I have never seen so many threads discussing intakes and exhausts. If you scroll down the section, I'd say half of the threads are discussing the gains of intake and exhaust. You know, there are more ways to modify your car to make it faster. For the people looking at turbo kits, it wont matter which intake you want to buy because you will need to get one that goes into the turbo. You will probably need a different exhaust too, since it will be coming off the turbo as well. Is anyone else worried about the engine management for the 8? what about some lightweight pullies and flywheels? Lets expand our horizons everyone.

not everyone is looking for such wild engine modifications such as turbocharging. intake and exhaust are usually a fairly inexpensive way to bump up some power, and for those looking for a few aftermarket goodies for our 8's, we want our hard earned cash to go well spent, so we try to research as much as we can before we buy.

true, there are ALOT of intake/exhaust posts in the aftermarket tech forum. i just take it for granted that i am able to use the search function and keep myself updated on most new happenings in the rx-8 community. some are not so computer literate and may have a hard time finding a specific answer, so they just post a new thread because they don't know any better.

personally, i need to keep the factory warranty so im probably only going to be putting on mazdaspeed parts. as for exhaust, thats probably going to be the only engine mod i can do, so im gonna wait until most new systems are out.

People are talking about intakes and exhaust because that's about all that's available! I guarantee you if there were turbo kits available someone would be talking about them.

jds

I agree with Rex, There needs to be a broader range of things to do. A flywheel is inexpensive, and the lighter weight makes the shifts quicker, increasing acceleration and performance just for an example. Engine management is of the utmost importance for this vehicle. its not about being computer literate, its about knowing how a damn engine works. It seems like everyone here has just watched fast and the furious, and looks at the intakes and exhausts. I guarantee there are things less expensive than the fricken rotary extreme intake which is way too costly for the measly 10hp it gives. Lets get educated folks, this car has so much potential, it just needs some learned, experienced attention. People need to stop stupifying this forum, whether they mean it or not.

Agreed. So let's talk about what ELSE can be done to the car. How about someone lists out all the other possible mods?

its perfectly natural to be talking about these things. the car is too new.

well i think if we start talking about what we want to get done, and what we wish was in the market, hopefully the manufacturers will see the demand and make the parts. I guess mazdaspeed has a pully kit that is available, but i doubt that is much lighter than the stock pullies. It seems that really lightweight pullies should be easy to manufacture, and deffinately an easy way to make power. We can start with those. What else do people want to see go on the 8 to have it make more power. This can be everyone's wish list, throw something out there and we'll expand on it, discuss its feasability.

Lighter flywheels are always a great mod.
I am reluctant on underdrive pulleys though. Lighter underdrive pulleys are, in some engines, associated with harmfull engine vibrations that can shorten the life of the engine or simply cause engine failure. This is due to the fact that many aftermarket underdrive pulleys are not harmonically balanced, which, from what was explained to me by some master mechanics (they mainly worked on ford, chevy, and honda engines), amplifies the engine vibrations.
This may not be applicable to the renesis, but its certainly something to consider. Many people use underdrive pulleys without a problem, but some do face concequences... Time to start getting some renesis mechanics in here to comment and enlighten us I guess.

How about some port and polish work? Are there manifolds in the 8 that can be optimized? Throtle body?

Yes, I have heard that with pullies. Deffinately something to consider before purchasing. The lightened flywheel along with strengthened clutch is always great. I'm not sure of the strength of these 6MT's but I'm sure time will tell with that. I am not too familiar with the port and polish work because I am ued to 4-strokes, anyone else care to comment?

Originally posted by bureau13
People are talking about intakes and exhaust because that's about all that's available! I guarantee you if there were turbo kits available someone would be talking about them.

jds


there's a few bolt-on turbo systems avail in japan. also a bunch of intakes and exhaust systems too. i do not know when or if they will be available in the US though.

Originally posted by Buster77
I agree with Rex, There needs to be a broader range of things to do. A flywheel is inexpensive, and the lighter weight makes the shifts quicker, increasing acceleration and performance just for an example. Engine management is of the utmost importance for this vehicle. its not about being computer literate, its about knowing how a damn engine works. It seems like everyone here has just watched fast and the furious, and looks at the intakes and exhausts. I guarantee there are things less expensive than the fricken rotary extreme intake which is way too costly for the measly 10hp it gives. Lets get educated folks, this car has so much potential, it just needs some learned, experienced attention. People need to stop stupifying this forum, whether they mean it or not.

A: It's what people are talking about because of a lot of 8 owners, such as myself, are new to this sorta thing and it's some of the easiest places to start.

B: Alright. We need ot be educated. Then educate rather than critisize. It's easy to say the car has potential. Why does it? I understand some of it so far, but cars are not my life and is a rather new hobby. I am still learning. You sound like you know stuff. Lets hear it.

Rotary engines are 4-stroke just like pistons...

As far as power pulleys, SR Motorsports has some that are already available. I'm not sure whether they are underdrive or just lightened, though.

I also was curious about Throttle Bodys for the 8, but I don't recall ever seeing that as an option for any other NA rotary like the FC.

shadowcougar...

For most of us, a light flywheel would not be a great mod. Sure, it would allow the engine to increase and decrease revs faster, but the reduced mass would make the car less driveable. Great for racers, not so great for us average Joes. CAT back exhausts are mainly cosmetic and no CAT is not an option to most of us, leaving JUST released intake systems and NOT YET released and unverified Canzoomers' CZ mod the main stories so far. I'm with djmano, except I am not as worried about the warranty and ordered Rotary Extremes intake. I don't have the budget for any turbo!
Tom

Throttle bodies are largely pointless. Anyone know how much the stocker flows and what the max amount of air the stock engine can *take* is? Bigger isn't always better. You want to make a throttle body worth something you need to go internal on the engine to increase the flow *there*, thereby necessitating the larger throttle body.

I'd love to see a twin-plate clutch/lightweight flywheel combo. I dunno what people are complaining about as I have found 11lb flywheels to be perfectly accesptable for everyday use, even in larger cars driven in snow ;)

Lightweight pulleys are one thing, underdrive is another. I'd take lighter pulleys, but stuff the underdrive units. Especially considering the weakass stock battery, the last thing you want to do is underdrive your alternator.

The most important thing is really going to be programmable engine management, same as with any car that will be modified. Consider that your "foundation." Without that, any intake/exhaust/turbo/NA porting is a house of cards...

I am new to the whole rotary scene, but my understanding is that these motors are not balanced the same as a conventional piston engine so the vibration issue (with pulleys) is irrelevant? Please correct me if I'm wrong. Also, I know that most of us can't remove the cat, however I keep hearing about how the ECU is so concerned about keeping the exhaust temperture down so it doesn't fry the cat because rotaries tend to run hot. This would make me think that removing the cat and tuning that would take advantage of it would yield some serious power increases. A bolt- in "race" pipe that you could switch out for the cat once every year or two when emissions comes around would be perfect. Any thoughts?

Rikki, I mentioned lightweight pulleys..

I'm not endorsing their effectiveness.. its one of those "placebo-esque" mods anyway. But we were talkin' about every possible avenue..

Aren't you gonna chime in with the tornado? ;)

Ok, so here's a synopsis of what's been suggested so far:

- Lightweight pulleys, standard size or underdrive
- Lightweight flywheel
- Twin-plate/Strengthened clutch
- Port and polish work? Are there manifolds in the 8 that can be optimized? Throtle body?

Is this it?? Seems like a pretty SLIM list. And a twin-plate/strengthened clutch isn't even a performance enhancement per se, but more a way to keep things from blowing up your tranny and/or differential when your engine puts out more HP than the car was originally designed for.

Back in the day when I was into hotrodding cars, the rotary was not something I worked on. Mostly worked on small and big block V8s, with the occational I4 or I6 mixed in. I have no idea about ECU tuning, although I can understand the theory behind it. But the basics remain the same, and back in the old days we used this basic formula for "souping up" an engine, in roughly this order usually:

- Intake element and manifold (reduce restriction)
- Exhaust: Headers/manifold, piping, and mufflers (reduce restriction)
- Hotter ignition system
- larger fuel system (bigger or hotter carburator and fuel pump, and in later years, adding fuel injection)
- porting and polishing heads
- more radical cam(s)
- changing gearing in the transmission and/or differential
- higher base compression
- forced induction, usually via a Supercharger
- strengthened internals (usually required with higher compression and or forced induction)
- strengthened clutch and/or transmission (usually required with more power from above mods)
- balancing (and/or blueprinting) engine

Now a few of these don't apply to the rotary, such as the hotter cams, and others have been discussed ad naseum (intake, exhaust and forced induction). Pretty sure we don't want to boost the base compression of the engine, as it's already pretty high. So that leaves

- Hotter ignition system
- porting and polishing
- changing gearing in the transmission and/or differential
- balancing engine

I have no idea if a hotter ignition would help the rotary, although I suspect modern ignition systems are so much better than the old "coil and distributor" systems that they don't need much improvement. Dunno, does anyone think this could help?

I'm pretty sure both the intake and exhaust ports could at least use a smoothening. Seems I also heard somewhere that adding headers to this car don't do much either because of the angle of the exhaust ports negates the potential flow increases of the header, but if it were cut down by some angle (perhaps 22 degrees?) it would flow much better.

I'm also sure changing the gearing would help, although I doubt many of us will tackle it. Back in my day, a 3:96 or 4:11 differential gears were the hot setup for drag cars... does anyone know what the gear ration is in the 8? This area has potential....

Also not sure if balancing this engine would help. Anyone?

Then there's the lightweight flywheels and pulleys mentioned at the first of this post.


What else? Come on folks, let's brain storm here....

Not sure if this applies to the 8, but would limited slip differentials help??? (try to put some more power to the ground...)

Good thought, but the 8's differential is already limited slip.

I'm going to throw nitrous out there just because no one has said it yet. I heard the renisis can't take it, but can anyone confirm this? It might be good for some decent power.

Originally posted by Omicron
Good thought, but the 8's differential is already limited slip.

Well, worth a shot...

Don't think this will work as the renesis is such a new engine, but short of an engine swap, are there any other compatible rotary engines that have parts that can be adapted to the renesis? If so, there's always the possibility of some hybrid work...

I have a friend that put a 6oz underdrive crank pully on his turbo civic to replace the stock 7lb one! He saw a big increase on the dyno. I dont know the exact number but he lost .2 in the quarter mile.

Originally posted by Turborex
I'm going to throw nitrous out there just because no one has said it yet. I heard the renisis can't take it, but can anyone confirm this? It might be good for some decent power. Good thought, although not for everyone. Ok, I'll add it to the list.

So here's the updated list:

- Lightweight pulleys, standard size or underdrive
- Lightweight flywheel
- Port and polish intake/exhaust?
- Intake/MAF and exhaust/header (manifolds) improvements?
- Throtle body improvements?
- Hotter ignition system?
- Changing gearing in the differential
- Changing gearing in the transmission
- Balancing the engine
- Twin-plate/Strengthened clutch
- Nitrous Oxide

And of course, the old standbys:

- Cold Air (or less restrictive) intake
- Less restrictive exhaust
- Less restrictive (or completely removed) catalytic converter
- Supercharger or Turbocharger

Falls into intake, but its only worth it as one of the last mods:
Calibrated MAF

Please keep in mind that i'm tossing ideas based on my knowledge of ford engines, which might have no significance to the renesis.

shadowcougar, good point..

I have heard of massive gains to be had by putting on a larger MAF, especially on the SHO engines.

we should add a tuned ecu to that list. If we can lean out the mixture we will get more power. Also if we can get more fuel and more air through the manifold we will end up with more torque. Is there any way to control ignition timing on rotories? Advance the timing to make more power as well.

yeah, what he said...

For whoever asked it, the rear end ratio on the RX-8 is 4.44:1!!!

FYI callibrated MAFs dont add a lot of power unless you already have significant mods. Think about an extra 5 hp (10 if you are really pushing mods).

Sports chips, ecu's, etc are always good add-ons, but like maf I would do them last, in order to properly calibrate for all mods and have a better fuel/air mix (some sports chips mess with that...). I just don't like the idea of paying an extra 100 to 200 to do a custom burn every time I change or add something...
After a certain degree of mods, fuel management systems are a must.

No doubt about it, one must pay to play. Power costs money...

4.44:1??? WOH!! Dem's drag racin gears back in my day!

So here's the new updated list:

- Lightweight pulleys, standard size or underdrive
- Lightweight flywheel
- Port and polish intake/exhaust?
- Intake/MAF and exhaust/header (manifolds) improvements?
- Throtle body improvements?
- Hotter ignition system?
- Changing gearing in the differential (may already be optimal)
- Changing gearing in the transmission
- Balancing the engine
- Twin-plate/Strengthened clutch
- Recalibrated ECU for fuel and ignition

And of course, the old standbys:

- Cold Air (or less restrictive) intake
- Less restrictive exhaust
- Less restrictive (or completely removed) catalytic converter
- Forced Induction: Supercharger or Turbocharger
- Nitrous Oxide

What else? Anyone want to comment on a "hotter" ignition, and/or balancing?

Going with a flywheel is not cheap. Labor alone is $300. Most people do it when they replace their clutch since the tranny has to comeout anyway.

Jason
www.rx8store.com

Perhaps low compression rotors, or crate engines, will be offered for high boost applications in the future also...

Ok, so here's the list re-sorted by areas where products are either already on the market, in development and will be out soon, or nothing in development as far as I know:

On the market now:
- Lightweight pulleys, standard size or underdrive
- Lightweight flywheel
- Cold Air (or less restrictive) intake
- Less restrictive exhaust
- Exhaust header

In development and will be out soon:
- Twin-plate/Strengthened clutch
- Recalibrated ECU for fuel and ignition
- Less restrictive (or completely removed) catalytic converter
- Forced Induction: Supercharger or Turbocharger
- Nitrous Oxide

Not under development as far as I've heard.
- Port and polish intake/exhaust?
- Intake manifolds and MAF improvements?
- Throtle body improvements?
- Hotter ignition system?
- Changing gearing in the differential (may already be optimal)
- Changing gearing in the transmission
- Balancing the engine

So I guess what we need to establish at this point, is
(a) Have we got everything on the list that can be done to the Renesis engine to make it produce more power?
(b) Can anyone talk to these areas that still need be developed?

The "port and polish" as you refer to it will be done by aftermarket shops such as rotary performance. I port all my own rotaries and I'd love to peek at the Renesis. Eventually someone like Mazdatrix will come out with a porting template for it.

This intake manifold is far and away better than anything Mazda has ever built before. Since each port has its own tuned length runner, this may be hard to improve upon without sacrificing certain parks of the powerband. The throttlebody can already provide enough air for 9500 rpm. I only suspect a throttlebody would do any good if the engine were extensively ported but until we see the extents of this we won't know.

Abetter ignition system is a great idea. All the RX-7 ignitions systems whil already very good, could be improved upon with the addition of a simple box such as an MSD or equivalent. I had the MSD on both of my RX-7s and the result was always a little smoother running with much improved top end power.

Balancing the engine would help a small amount. Do this while it is being ported. Try seeing if the engine can be lightened any further. Racing Beat and Paul Yaw both can lighten rotors and balance the assemblies. I'd try to find a way to add a center bearing on the eccentric shaft in the intermediate housing. Guru racing offers eccentric shafts like these for the 12A and 13B engines but the buyer needs to modify the center housing themselves with the supplied template. This bearing would greatly reduce shaft flex and more safely allow higher rpms. Take note however that the automatic engine and the standard engine have different part numbers for their eccentric shafts. This is a first for the same car. I would also see if the apex seal area can be enlarged to allow the deaper 2 piece 2mm 13B apex seals from Rotary Aviation. Solid corner seals could then be used too. This would make the engine very tough in regards to detonation. The Rotary Aviation seals are very hard but can easily survive lots of detonation. Good for future forced induction.

That's what I would do.

Glad to hear a real rotary expert weighing in on this. But I thought you were the "Audiogod?" :D

Seriously, to speak to your last point first...

Originally posted by rotarygod
I would also see if the apex seal area can be enlarged to allow the deaper 2 piece 2mm 13B apex seals from rotary Aviation. Solid corner seals could then be used too. This would make the engine very tough in regards to detonation. The Rotary Aviation seals are very hard but can easily survive lots of detonation. Good for future forced induction.

CanZoomer is already working with a rotary tuner in Canada on this, fitting ceramic apex seals, as well as remachining the rotors to reduce the compression and make the engine more resistant to detonation and better
suited to forced induction. Hopefully he'll chime in here and tell us more about it. We've talked on the phone quite a bit, but that's the best level of detail I can provide right now.

As for the rest of your post...

It sounds like the intake manifold and throttle body are close to optimal, so not much work to be done there. We'll see if someone improves it as time goes on.

We'll also have to see if someone comes out with a better ignition system, or tries the addition of a simple box like an MSD or equivalent. Time will tell.

Sounds like you think the "port and polish" would help, but needs some serious development to determine the best grind angles, etc.

Finally, what probably really needs to be done is for some rotary tuner do a serious (re)build on the engine. While it's apart they can do the port and polish job, and install stronger apex seals. Another strengthening measure that could be done while the engine is apart is to find a way to add a center bearing on the eccentric shaft in the intermediate housing, which would greatly reduce shaft flex and more safely allow higher rpms. They may also seeing if the engine can be lightened any further, and possibly balance it.

Hopefully someone on the forum will begin working on these mods, and let us all know. Racing Beat, Guru Racing, and Paul Yaw are all possible future developers. Not sure if our board owners here, VividRacing, does actual engine development or not, but hopefully they do and will jump on the bandwagon too.

My PERSONAL basic plan for my '8, assuming time and funding allows, goes as follows:

Stage 1:
- Borla catback exhaust (Done)
- Racing Beat Cold Air Intake (On order)
- CanZoomer's "Stage 1" fuel controller ECU piggyback (On order)
- Possible: CanZoomer's "Stage 2" ignition controller ECU piggyback and high temp/high flow replacement cat

I will probably hold at this level of mod until the manufacturer's warranty runs out. Too many risks without it in place. Then, when it expires, I'll go to

Stage 2: Magor engine work, adding
- Forced Induction... SC or TC, we'll see what's on the market and has proven to be best
- Lightweight flywheel and pulleys
- Center bearing on the eccentric shaft
- Ceramic Apex seals
- Slightly reduced compression ratio, so my FI can be set to higher boost
- Intake and Exhaust port and polish
- Exhaust header
- Improved ignition (if available)
- Twin-plate/strengthened clutch
- Overall balancing of engine

Hopefully a "crate motor" will be available by the time I'm ready to do this with some or all of these mods. I suspect it will be, then all I'll have to do is drop it in and bolt on the FI. :D

On the subject of upgrade stages, I'm curious to see who, and when, some of the numerous rotary tuners in the U.S. market will come out with some complete stage kits. Similar to what M2 or Petit have done with the FD.

I think that's only a matter of time. The car's just too new for much to be on the market now.

Originally posted by Turborex
I'm going to throw nitrous out there just because no one has said it yet. I heard the renisis can't take it, but can anyone confirm this? It might be good for some decent power.

I am sure it can. There got to be a way. However, NOS is a really delicate thing to pour into any engine, if the installation, the timing are wrong, everything will be over in minutes. For regular engines, a lot of people have gone through this, and they developed enough experience and skill.

For the Renesis engine, you can try that, and you are most likely gonna be a guinea pig. Let us know how it goes if you decide to put NOS in your 8, maybe someone comes along will learn from your experience and do it a bit better, or worse.

Haha i think i'll wait for someone else to try it first. BTW Omicron, does canzoomer have a website or is he producing these parts for public sale? If so I know some people who would be very interested. If not he deffinately should, it seems like there is plenty a demand for power on this site!

Ahhh... i found him on the vendor thread. Nevermind

CanZoomer should have a website up soon, but I think his priority right now is getting the first batch of ECU piggybacks built and out to door to demanding customers like me. :)

In the mean time, you can get a hold of him via the Vendor's forum (which you already found) or via email: maurice@harddata.com .

Also, if you want to read up on what he's done in developing this ECU piggyback, check out this thread: http://www.rx8club.com/showthread.php?s=&threadid=11614 It's really long (28 pages last I checked) but is a fascinating, and worthwhile read.

Red Line or Royal Purple oils. Cheap and will add a few wheel ponies. You can buy them for the motor, tranny, and differentail.

I know Horespwoer TV tested them on an SS Camero (newer model) and it gained 9 whp.

Hmmm, sounds like too big a gain for such a small change. Are they synthetic, and if so, doesn't Mazda tell us we cannot use synthetics? If we do, we run the risk of voiding our warranty. I guess I'll have to go read that thread about synthetic oils...

Originally posted by rotarygod
Abetter ignition system is a great idea. All the RX-7 ignitions systems whil already very good, could be improved upon with the addition of a simple box such as an MSD or equivalent.

Balancing the engine would help a small amount. Try seeing if the engine can be lightened any further. I'd try to find a way to add a center bearing on the eccentric shaft in the intermediate housing. Guru racing offers eccentric shafts like these for the 12A and 13B engines but the buyer needs to modify the center housing themselves with the supplied template. This bearing would greatly reduce shaft flex and more safely allow higher rpms.

I would also see if the apex seal area can be enlarged to allow the deaper 2 piece 2mm 13B apex seals from Rotary Aviation. Solid corner seals could then be used too. This would make the engine very tough in regards to detonation. The Rotary Aviation seals are very hard but can easily survive lots of detonation. Good for future forced induction.

That's what I would do.

the points on how to get more RPM out of the motor are good, but missing: race clearancing of the housings, lightening of the e-shaft... but one thing i'm curious about, thinking about it: how the heck are e-shafts made?? ground out of some billet alloy?? or are they a forged alloy?? cast alloy????

does anyone know??

ok, and for Omicron, cams and porting go together as just porting for the rotary. your comment about "what grind angles would be best" is, um, innocent. there's never ever been agreement (anywhere i've found) about shapes, sizes, smooth vs. rough, etc etc etc as far as rotaries go. it's a completely black art. everyone's got different ideas and theories (the only thing you'll ever hear at nopistons.com is "AS BIG AS YOU CAN GOOOO!!!", no matter your target output level), and it's all a little dodgy.

now, because of the new location of the exhaust ports, AND the fact that they're now side ports as well, this opens up quite a few funny things that can be done: once someone can open up this engine and publicise the quantified timing of the ports (the exhaust being the biggest unknown to me), the rotary wizards can crack their knuckles and begin to plan some port shapes. i think it might actually be possible to run a small bridge on the secondary and primary port, with an additional bridge on the tertiary port (i think they're still sleaves, so you'd have to cut those too... OH!! and get the Pineapple racing inserts) while still keeping a streetable amount of overlap (2-5 degrees) in the system.

a HUGE area of import is the back side: how to tune that bloody siamese port???
well, RG has some big fancy ideas, but another solution is to try and keep separated the two pulses entering the centre port with further baffling in the middle, porting out the sides, and creating a custom header with two runners to keep the pulses apart until the collector. i'm sure RG's idea would be a lot less work, money, and riskiness, so get him to re-detail the whole procedure (a big, huge, fancy header with dead legs and the runner from the siamesed port collecting with the others like 3x the length down the way... or something).

The center bearing negates any need for race clearancing. The reason engines have their clearance increased for high rpm's is because the factory eccentric shaft flexes slightly due to the lack of center support. The extra clearance is needed on the sides so the rotors don't go crashing into the side and intermediate housings. Hurley has run a custom eccentric shaft engine to 12000 rpm with no race clearancing and Guru Racing takes theirs to 10000 rpm. The biggest issue at this rpm is the bearings failing. I'm not so concerned with getting any more rpm's out of the Renesis but rather making it stronger so that it can take the abuse of forced induction, nitrous, etc. and still maintain high rpms's for a long amount of time.

Well, thanks for calling my comments "innocent" and not "stupid" Wakeesh, that's mighty polite of you. I know what you really wanted to say. :D

I have just been trying to get and/or keep the discussion going here on ways we can improve the Renesis. If you look back over my original lengthy post, you'll see that I made no secret of the fact that most of my experience (almost 20 years ago, sheesh!) was with piston engines. I'm a total neophyte to tuning rotary engines, and like many of us here, am just looking to get the REAL rotary experts - like you and Rotarygod - to chime in.

One of my main points is that to really extract more power out of the Renesis, it's going to take a professional rotary tuner to do it, who has the proper equipment and knowledge needed to go messin around with the engine's internals. The best the rest of us can do is to bolt on performance goodies, which will have limited results.

What I'm really trying to do here is to get a professional rotary tuner engaged and thinking about what they can do, then to begin DOING it. I'm really hoping to be able to buy a thoroughly massaged "crate motor" Renesis putting out 400+ WHP about the time my Mazda warranty expires. :D

Omicron, Ill be right beside you. An 8 with 400whp and coil overs (one set giving 1.01 g's on the skid pad, only topped by lets say, an enzo) would be one of baddest cars on the road, anywhere.

No doubt! :D But why coilovers, and not just replacement springs, sway bars, etc? Or are you already aware of some coilovers already on the market for the '8 that give this kind of performance? If so, who makes them? Can you provide a link?

Omicron,

Here's the link: http://www.rx8club.com/showthread.php?s=&threadid=14806&perpage=15&pagenumber=2

This guy has a RX-8 equipped with JIC coilovers, he talks in his post about how he is going to be featured in SCC soon, and they tested his car on the skidpad and that he pulled 1.01 G with the JIC's.

Nice! Now if I can just find out how much, if at all, they change the feel of the car in daily driving...

Originally posted by wakeech
well, RG has some big fancy ideas, but another solution is to try and keep separated the two pulses entering the centre port with further baffling in the middle, porting out the sides, and creating a custom header with two runners to keep the pulses apart until the collector. i'm sure RG's idea would be a lot less work, money, and riskiness, so get him to re-detail the whole procedure (a big, huge, fancy header with dead legs and the runner from the siamesed port collecting with the others like 3x the length down the way... or something).

What about keeping the siamese port's pulses together (no baffle) using equal lenght runners on the header but different diameters? Wouldn't this be a way to tune the pulses?

Different diameters wouldn't matter and probably wouldn't be a good idea since you don't want to slow down the inertia that the exhaust gas has. Velocity over volume. What would be beneficial is to use a different length center runner with a dead leg pipe off of it to fool the center port into acting like the outers. I really need to draw a picture.

Originally posted by rotarygod
What would be beneficial is to use a different length center runner with a dead leg pipe off of it to fool the center port into acting like the outers. I really need to draw a picture.

^^ what i was talking about before ^^, but he's the only one that actually knows what's going on with it.

thanks for the info on the centre shaft bearing: is it just another bearing as you'd find in the end plates, or a part from one of Mazda's 20B's with the 2 peice e-shafts??

Custom needle roller bearing.

Originally posted by rotarygod
Custom needle roller bearing.

oh custom, hey?? and you say 12k rpm on a roller bearing?? :eek: woah.

...how's it get an oil feed?? tapped from the e-shaft?? er, wait... if so, how does it drain??

and just a reminder: it's past your bedtime ;)

Having been somewhat involved in several aspects of the canzoomer project I will tell you this. It really makes that little rotary rock hard. Nice drivability and fun to drive.

Having seen the poorly designed apex seals of this engine. Put this in writing " There is no way that engine will survive any substantial amount of boost and one bad batch of fuel will finsh that engine.

Too much compression.
Too thin of apex
Too popr of material in the Apex( you would have though Mazda would have gone right to the ceramics)

I'd still just rather find a way to mill out the rotor to use the Rotary Aviation 13B apex seals.

There is already a nice 3mm solution just bolt a turbo on stock and you gonna have issues

Here is some stuff Racing Beat is currently working on performance wise...

- Lightweight Race Rotors
- Exhaust Headers
- Engine Balancing
- Porting


I am thinking what we might not need to reduce compression to get good boost. If we can get some stronger seals, we should be able to run 12-15lbs. At least this is the impression I am getting for Rotary Reliability. I think Christmas time next year the market will start to explode for the RX8. Should make things interesting.

Well hell, im glad to see a tread about something other than intake/exhaust, I personally am ready for more soon as its available, dont think ill try the NOS angle as i learned the hard way on my 13B :( (tried to install myself.....ahhhhh ill just leave it at that)

I'm with you Omicron, a complete packaged 400-450hp setup would be great. But I imagine with that much power the transmission will need attention.

When I buy the car in the spring, after the winter, I think I will purchase Canzoomer's Stage 1, and then concentrate on Suspension and weight reduction.

As someone else said, will just have to wait and see all the power options around a year from now.

Originally posted by Red Devil
I'm with you Omicron, a complete packaged 400-450hp setup would be great. But I imagine with that much power the transmission will need attention.By the time crate motors become available with this kind of power, I'm sure stronger transmissions will be available too. :D

When I buy the car in the spring, after the winter, I think I will purchase Canzoomer's Stage 1, and then concentrate on Suspension and weight reduction. As someone else said, will just have to wait and see all the power options around a year from now.Me too, except I'm probably going to go pretty quickly to the Stage II with a high flow metallic cat, and I've already added a cat-back exhaust and better intake.

If you're after weight reduction, when you purchase your car, you may want to go with just the base model + sport package only. This'll save you some weight in power seat motors and other doo dads. I'd also be interested in what other ideas you may have for weight reduction... it's been discussed before here, and short of gutting the interior (which I personally am not willing to do for the few pounds it'll save) not many good ideas have been come up with.

I've noticed there aren't many weight saving options right now. But I'll be hopeful and see what the more mechanically inclined can come-up with.

Some things I've seen through the years, or what's been mentioned on the forum already:
-Fiberglass Body Paneling
-Lightweight Seats (loss of side airbags, correct?)
-Sunroof Motor Removal (T/GT package - Installing a removable top model saves about 18lbs on an FC)
-Complete titanium Exhaust
-Titanium Bolts/Washers/Nuts/Wheel Stars
-Carbon Fiber Strut Braces Front and Rear
-Replacement Titanium Chassis Braces (saw custom fabricated on a Vette, probably $$$$)
-Ceramic Brake Rotors (heard they don't last long, though)
-Lightweight Wheel (I've seen that the 8's are already very light)
-Racing Battery
-Aluminum Engine Housings
-Aluminum Radiator (always seem to be lighter than OEM)
-Flywheel

Perhaps at least some of those have potential, and none of which would sacrifice comfort or driveability of the vehicle. And the custom Ti work, I have no idea what it takes, or who was involved in doing the fabrication. I'd like to remove another 100-150lbs out of the car. But I do think that may be difficult.

As for the transmission, I'm sure upgrades will be available; I was more stating it because I think it is a necessary cost that is often overlooked.

And Sport Package is almost definitely the way I'm going. Not the GT, don't appreciate leather anyway.

WHAT ABOUT RACING BEAT?? DID THEY HAVE SOME THING NEW????

besides engine mods the best performance you could get would be weight savings, it increases performance in every aspect breaking, acceleration, cornering whatever, the only performance peice Ive seen that uses this idea was the full titanium exhaust, I personally would like to see more performance peices with this idea in mind.

Let's see:
Ignition - possible but expensive as there would be four boxes required and four coils. Would need to address the effective "leaning out" (see my post in main discussion - multi strike iginitions).
Underdrive pulleys - these will work, though in my opinion they don't give HP, they allow the engine to loose less when speeding up, and they could be effective in reducing cavitation in the water pump (a la 3rd gen RX-7). They are also pretty ;) I don't see any problem with the charging system.
Porting/polishing - RX-7 Specialties in Calgary are working on this (among others). Adam has crate renesis engines to "play" with. I hear via the "grapevine" of some good progress.
ECU mods - limited to "piggyback" systems for now due to the extent the ECU has it's hands into the entire car. Canzoomer's stage 1 is in production/shipping. Stage 2 still has work to be done, but preliminary results are scary (to 3rd gen owners) as it puts the RX-8 at or past 3rd gen performance without turbos. It is "on the edge" enough that altitude compensation will probably be necessary to avoid detonation. This is already in the car BTW.
Transmission - this is an area that will need work soon. It's a unit from the Miata, a car with 150-170 HP. Torque is close to the renesis, but once we start getting up above 250 HP at RPMs of 5000-7000 the torque will surpass the transmissions' abilities.
Weight reduction - this is an area we can really benefit from. It improves performance without stressing the car. Question is, what did Mazda miss or "cheap out" on. e.g. My 3rd gen has steel brackets holding small pieces on the engine. By making replacements out of aluminum, I was able to drop 10 lbs in a few hours of work. That is what we want to find on the RX-8. Don't scoff at just 10 lbs, it adds up. Quickly. Read Yamaguchi's book on the 3rd gen RX-7 to see how.
Wheels - if you want to drag race, go smaller diameter with larger aspect ratio so the sidewalls can flex. This can greatly reduce wheel hop. You can get lighter wheels too, but you have to have good credit ;)
Battery - I'd consider moving it to the trunk, but only to improve weight distribution. You would need a sealed one if you did this, and Optima now make a size 50 series.
This is getting long so I'll continue it later.

What about replacement of the PPF, if I'm not mistaken they are made of steel. Switching to titanium or aluminum - not sure if aluminum is strong enough for the application - could save a lot of weight.

Nice, well thought out post RX-8 friend, please continue where you left off.

Coupla thoughts...

ECU mods - Could you elaborate a bit on the preliminary results of the CZ Stage II mod? (OMG! The RX-8 at or past 3rd gen performance without turbos? :D) What's the best GTech time and HP/torque estimates that've been obtained with the Stage II so far? Also, you say it is "on the edge" enough that altitude compensation will probably be necessary to avoid detonation, and that "This is already in the car BTW." Do you mean the altitude compensation is already in the car? If so, then why bring it up explicitly?

Transmission - I know there are Miatas out there putting out 350+ HP, so what are those people doing about the tranny? Is there a pre-made, stronger unit already in existance that would work for the '8? If the trannys really are the same, I would think there would be...

Weight reduction - Great way to go about it... I will start looking for bracket and metal bits that can be remade! :)

Wheels - Are you talking like 17 inch rims, or 16s, or what here?

Well, the stage 2 tests took the car into dangerous territory last fall (burned out coil packs, overheating, etc.) so testing was stopped until stage 1 was in production and we could figure out how to safely proceed. I'm told MUCH HP was seen but I'll believe it when I see it myself. The tests were abreviated due to the above problems. Understandable at those power levels, BTW. We are beginning to understand what caused the problems, and are becoming confident enough to proceed in the spring. Any who go this route should consider carefully if they really want to go into this extreme engine environment. It will mean you have to watch closely what is happening at all times. You -will- be close to the edge. Just like my car <- :) .

If you look just behind the ECU you will see a small black device mounted next to the shock tower with a short hose going straight down. That is the pressure sensor for altitude compensation. Stage 2 may require an input from that sensor (it feeds the stock ECU only on stage 1).

From the Miata people I've talked to, those with stock transmissions (6 speed) break them when they add turbos. The 5 speed Miata transmission is from the RX-7, and is strong enough (most of the time). Most of the turbo conversions have so far been done on the older cars, so there isn't a lot of complaining yet.

For drag racing, 17s I think. I don't think 16s will clear the calipers. The "hot setup" on 3rd gens is 15" on rear only, with 3rd gen spare wheels on the front (weight and air resistance reduction). 16s may clear the rear calipers on the RX-8.

Exhaust - (yeah, I know, this thread is OTHER than intake and exhaust) - BUT, no-one has considered 2-stroke technology. Yes, the rotary including the renesis is "4 stroke", but really it's a "continuous combustion" engine. There are no "strokes". Many people like to compare it to a 2-stroke, but it's similar only because it is "piston ported" (rotor ported). Now, in a 2-stroke engine, to extract "unreal" power (how about 150+ HP from a 500 cc), we use the exhaust pulses to suck the exhaust out and force charge the combustion chambers. This is not possible with a turbo (it blocks or interferres with the pressure waves). With a NA however, it is possible. What you do is put in a pipe feeding a resonant chamber just after the exhaust port. The end of the chamber is shaped to reflect the exhaust pulses such that the pulse exiting the engine lasts long enough to suck fresh intake charge into the exhaust system, and when the pulse wave reflects back it shoves this extra charge back into the exhaust port. This requires one to design the porting and the exhaust as one system. Yes, it will start to sound even more like a "weedeater", and yes, it will almost double the engine output (if the internals can stand that level of power). Oh, and yes, fuel economy means you can get from one gas station to the next ;) .
Something I've always wanted to try, being a 2-stroke M/C fan. I think I've got Maurice enticed (he also is familiar with 2-stroke tech). Maybe sometime later this year....
Aero - next time.
PPF in aluminum is a possibility. As I recall, aluminum has to be thicker than steel for the same strength, but not enough to be as heavy. Could save perhaps 20 lbs. I don't think titanium is a cost effective option (unless you think the titanium exhaust is inexpensive - then go for it ;) .

I agree that Ti is very expensive, and I don't know if it is, or isn't, much more labor intensive than Steel or Aluminum. I just like to throw around the option because of its inherent strength and weight advantages.

Great responses RX-8 friend, and MUCH appreciated!

Originally posted by RX-8 friend
Well, the stage 2 tests took the car into dangerous territory last fall (burned out coil packs, overheating, etc.) so testing was stopped until stage 1 was in production and we could figure out how to safely proceed. I'm told MUCH HP was seen but I'll believe it when I see it myself. The tests were abreviated due to the above problems. Understandable at those power levels, BTW. We are beginning to understand what caused the problems, and are becoming confident enough to proceed in the spring. Any who go this route should consider carefully if they really want to go into this extreme engine environment. It will mean you have to watch closely what is happening at all times. You -will- be close to the edge. Just like my car <- :) .Hmmm, not sure I want to be that close to the edge, especially when I'm certain some FI kits will be out by the end of 2004 that will give the same or more preformance without going to quite this extreme. But we'll have to see what exactly the Stage II looks like when it comes out... I'm sure hopin you and Maurice will be sharing the development of this unit with us. DAMNIT, now I wish I lived in Canada, so I could be directly involved in this! :D

Originally posted by RX-8 friend
If you look just behind the ECU you will see a small black device mounted next to the shock tower with a short hose going straight down. That is the pressure sensor for altitude compensation. Stage 2 may require an input from that sensor (it feeds the stock ECU only on stage 1).Ok, nice to know exactly where it is. Thanks.

Originally posted by RX-8 friend
From the Miata people I've talked to, those with stock transmissions (6 speed) break them when they add turbos. The 5 speed Miata transmission is from the RX-7, and is strong enough (most of the time). Most of the turbo conversions have so far been done on the older cars, so there isn't a lot of complaining yet.A 5 speed? Damnit, but I like the 6 speed! ;) Now I'll have to start closely following Judge Ito's development on strengthening the factory 6 speed...

Originally posted by RX-8 friend
For drag racing, 17s I think. I don't think 16s will clear the calipers. The "hot setup" on 3rd gens is 15" on rear only, with 3rd gen spare wheels on the front (weight and air resistance reduction). 16s may clear the rear calipers on the RX-8.Hmmm, interesting. This might just solve the wheel hop problem the '8 has on a hard launch with stock tires and pressures. So if I were to run 17s on the rear and 18s on the front, how would that affect my car's handling?

Originally posted by RX-8 friend
Exhaust - (yeah, I know, this thread is OTHER than intake and exhaust) - BUT, no-one has considered 2-stroke technology. Yes, the rotary including the renesis is "4 stroke", but really it's a "continuous combustion" engine. There are no "strokes". Many people like to compare it to a 2-stroke, but it's similar only because it is "piston ported" (rotor ported). Now, in a 2-stroke engine, to extract "unreal" power (how about 150+ HP from a 500 cc), we use the exhaust pulses to suck the exhaust out and force charge the combustion chambers. This is not possible with a turbo (it blocks or interferres with the pressure waves). With a NA however, it is possible. What you do is put in a pipe feeding a resonant chamber just after the exhaust port. The end of the chamber is shaped to reflect the exhaust pulses such that the pulse exiting the engine lasts long enough to suck fresh intake charge into the exhaust system, and when the pulse wave reflects back it shoves this extra charge back into the exhaust port. This requires one to design the porting and the exhaust as one system. Yes, it will start to sound even more like a "weedeater", and yes, it will almost double the engine output (if the internals can stand that level of power). Oh, and yes, fuel economy means you can get from one gas station to the next ;) . Something I've always wanted to try, being a 2-stroke M/C fan. I think I've got Maurice enticed (he also is familiar with 2-stroke tech). Maybe sometime later this year....Now THAT's interesting!!! I'm sure we all will be awaiting news of further development on this with baited breath!!! :D

Originally posted by RX-8 friend
Aero - next time.Ok, it's NOW next time... care to elaborate a bit more? ;)

Originally posted by RX-8 friend
PPF in aluminum is a possibility. As I recall, aluminum has to be thicker than steel for the same strength, but not enough to be as heavy. Could save perhaps 20 lbs. I don't think titanium is a cost effective option (unless you think the titanium exhaust is inexpensive - then go for it ;) . Sorry to appear ignorant here, but metallurgy is not my field. What exactly is PPF?


Thanks for all the great info!

PPF = Power Plant Frame
It holds the engine, tranny and diff together as one unit.

Ti is more difficult to work on than steel or Al that's why it's so expensive apart from the actual cost of the material, of which I think would need less because of it's strength...

To reduce wheel hop you want to let the tire sidewalls absorb the grip/release that induces it. Next time your tires are off the rim, check out the sidewall stiffness of the 18" tires. No give. That's why the RX-8 has such bad wheel hop. So, you reduce the wheel diameter and increase the sidewall height (not 35 series but perhaps 50 series), and maintain the same -tire- diameter. This is for drag racing, remember. It will affect the handling in corners because the rear will "lean" on the sidewalls a bit more, so I would predict more oversteer if you did the rears only, which would be considered dangerous if it's bad enough (understeer is safe, oversteer is bad because the car can loop on you). So what 3rd gen owners have been doing is just buy two wheels and tires for drag racing, and put them on when going to the track or when they get there. Wheel hop is death to the diff. on the 3rd gen. That and rear half shafts. But only for extreme modded cars (more than 300 HP).

PPF - yeah, it's short for power plant frame. A neat addition to car design by Mazda. It's U shaped and bolts to the rear of the transmission. The driveshaft runs in the U and it bolts to the diff on the other end. As for cost, we used to call titanium unobtanium. It can be pretty expensive, just for the raw material. It work hardens so easily, it's really hard to work with. Just drilling holes in it is a nightmare (they use spark erosion machines when cutting holes for military aircraft). Hey, I've got some aircraft grade titanium 8-32 screws. I guess I'm rich! ;)

Aero - I'll just post a little as I'm having trouble thinking straight with the flu right now. Amazing how much energy it takes to think! The rear spoiler is mostly used as decoration. To be useful (downforce) it has to be up pretty high (12-18") and pretty large. Look at race cars. It also does almost nothing until you get close to 100 MPH. Further, it adds drag. Much more effective is a rear diffuser. It goes under the trunk and directs air flow out from under the car. It produces downforce (again, above 100 MPH), but doesn't increase drag. Still looks cool, too ;) . We'll have to wait to see if the RX-8 can benifit from it. With cars entered in a few racing series this year, we should see some wind tunnel work results soon. RE Am. is famous for these things.

In regards to the 2 stroke exhaust technology, some of those guys can do some incredible things with an exhaust. However the design qualifications between the Renesis and a 2 stroke engine are the exact opposite. A 2 stroke engine has to have a perfectly designed exhaust to get the most power out if them. You can have too good of a scavenging system on a 2 stroke engine. You can't on a Renesis or any other 4 stroke engine for that matter. On a 2 stroke engine since there are no valves, the intake and exhaust ports are open at the same time but not for the same duration. The key with this exhaust design is to be able to promaote good airflow out the exhaust port rather than the intake port and to not make it flow so well that there is alot of fresh intake air pulled out of the exhaust port. The exhaust port is slightly high in the cylinder than the intake port so that when the piston moves down, the air finds the exhaust port first since it opens just ahead of the intake port. The exhaust design helps continue pulling it out and makes sure the chamber is completely clean of exhaust gasses. Since the intake and exhaust ports are open at the same time for a while some of the intake air gets pulled in too. The exhaust needs to make sure that too much isn't pulled all the way through. 2 stroke technology relies heavily on acoustic tuning in the exhaust. This is why the pipes expand to a chamber of a certain size and then contract out the tailpipe. The expansion acoustically promotes scavenging but the contraction puts enough backpressure in the system to control flow through the cylinder. It scavenges yet has a controlled amount of backpressure all at the same time.

The Renesis has no port overlap at all. Even other 4 stroke engines have a small amount of overlap. With no overlap, there is no benefit from a 2 stroke exhaust design. We want as little backpressure as possible. We can't get an exhaust that flows too good. The expansion is benefical but we can accomplish the same thing in a collector and almost all race engines do. We do not want to add backpressure. The 2 stroke idea may be a neat experiment on a peripheral intake/exhaust race engine but on the Renesis it is the last design that we would want to try. A good idea but the wrong engine to try it on. There is alot to learn rom the people taht do design 2 stroke engines though. It is a very interesting topic for the technically inclined. Barnes and Noble has a 2 stroke theory book. Well, at least the one by my house does.

There are two ways to look at an exhaust system. One is "get rid of all the exhaust gasses with a low restriction pipe". The other is to use "acoustic tuning" to help with this.
As I read it, the renesis has port overlap. 2 stroke engines have port timing just like the rotary, though the exact timing is different. Early 2 strokes (and lots of current ones) didn't use expansion chambers, and their timing was different. The backpressure you are talking about is in the expansion chamber only (the "stinger" or exhaust bleeder tip is designed to vent the chamber just enough that as little acousic energy is lost as possible but all the exhaust gasses escape so as not to build up back pressure - that acoustic energy is the shock wave that makes the thing work). The exhaust port doesn't see backpressure (unless you are calling the reflected wave backpressure - it isn't), it actually sees a slight vacuum pulled by the acoustic wave. The effect would work just fine for a rotary engine as the exhaust would all be "sucked out" by the tuned system. The RPM range that this happens at is controlled by several factors (see "Two Stroke Tuners Handbook" by Gordon Jennings). Input pipe length, chamber input funnel length, chamber end funnel length, chamber volume, etc.

You're right about perfect design being required for peak power, but there were lots of "street" two stroke M/Cs with expansion chambers that worked quite well over fairly wide RPM ranges (my RZ-350 for example - 40 HP from 350 cc and my DT-200 - 30 HP from 200 cc).

If you want to object due to the two rotors complicating matters, there I'll agree. I'm not sure there would be room for two expansion chambers under the car. Also, if you wanted this to be a "street" system, I'm not sure how you would treat the cat.

As I said before, it's not whether it's 2 stroke or not, it's how the venting is done. Piston or rotor porting lends itself to tuned exhausts. The current exhaust on the RX-8 has a little bit of "acoustic tuning" already. This is probably why so little improvement has been made so far. All I'm saying is it's time to try this different method.

Originally posted by Red Devil
(discussing weight reduction opportunities)
-Lightweight Wheel (I've seen that the 8's are already very light)

Actually, the OEM 18" wheels are pretty porky - somewhere around 21 or 22 lbs. My 17" winter wheels (17.8 lbs ea) with winter tires are 6 lbs each lighter than an OEM 18" wheel/tire!

Regards,
Gordon

The Renesis unlike all previous rotaries has absolutely zero port overlap. In fact it has 64 degrees of dwell. Even on rotaries with port overlap, we do not have very much overlap in relation to that of a 2 stroke engine. On a 2 stroke piston engine there is a period of time where both the intake and exhaust ports are open in their entirety at the same time. This is only true on a peripheral port rotary and even then the rotor does not have to sweep back across the exhaust port to close. Even a peripheral port engine does not have the long duration of a 2 stroke engine in regards to overlap. As with exhaust gas velocity, acoustic energy also has high and low pressure waves. We have 2 different pressure waves in an exhaust or intake system not one and we must optimise both simultaneously to achieve the greatest results. Some of these waves do get sent back to the 2 stroke engine to slow down escaping gasses but are primarily focused at stopping the incoming fresh air mixture from passing through. This is where the acoustics come in. To say that a 2 stroke exhaust would work well on a rotary would also be saying that it could work evenly as well on a piston engine. Every piston engine in production has overlap and high performance race cars have lots of overlap. None of them uses a 2 stroke exhaust and they spend lots of time and effort on exhaust design. They have lots of overlap and don't benefit from it. The Renesis is an even worse candidate due to zero overlap so it will not benefit from it either. A properly collected 4 stroke exhaust system does scavenge a chamber clean. They already have the potential to achieve efficiencies of greater than 100% at certain rpm's. The problem with the Renesis is that the 2 center ports are siamesed. You will not get any benefit from any system until the center port is treated differently than the other 2 ports. This is why conventional headers will not do much. The expansion in a 4 stroke exhaust is best done in the collector. As an example, 2 pipes that are 2" in diameter are joined at a 2 1/4" collector that expands to a 3" pipe in only a few inches. This setup can actually promote scavenging through better mixture of each pipe with the other. If you are not using any collector you are now tuning strickly according to organ pipe resonance theory. Since we don't have a 2 stroke engine and have absolutely nothing in common with a 2 stroke engine other than lack of valves (this is not a qualification of similarity), I will stand by my words. 2 stroke exhaust technology will not work on the Renesis.

BTW: You named the book that I mentioned. I just forgot the name when I typed this up. Go check out these books on proper exhaust theory. 2 stroke theory is also mentioned in the textbooks. I do like the book from Gordon Jennings though. It is full of some fantastic info. It just doesn't apply to the Renesis.

"Scientific Design of Exhaust and Intake Systems" (265 pgs. or so)
"The Internal Combustion Engine in Theory and Practice Vol. 1: Thermodynamics, Fluid Flow, Performance" (570+ pgs.)
"The Internal Combustion Engine in Theory and Practice Vol. 2: Combustion, Fuels, Materials, Design" (500+ pgs.)

Not exactly easy reading by any means but full of more than anyone ever wanted to know.

Wow, interesting stuff RX8-friend and Rotarygod! I'm lovin this exchange. :)

For some reason I thought 21lbs was light for an 18" wheel?

I've seen Paul Yaw has his wheels coming out soon, I wonder how much they will weigh.

In the thread I believe it says about 2-3 lbs lighter than stock

http://www.rx8club.com/showthread.php?s=&threadid=9655&highlight=yaw+wheels

Originally posted by Red Devil
For some reason I thought 21lbs was light for an 18" wheel?


It is very light for a STOCK wheel, amongst the best!

Originally posted by Omicron
I'd also be interested in what other ideas you may have for weight reduction...

besides the obvious like lighter wheels etc- get a dremel tool, file, knife and scrape/cut/ slice an ounce off of every piece of plastic/metal/fabric, that you can safely, in the car. with like a million parts in the car you could conceivably take of a half a million ounces or more.

Let's see here, 16 ounces per pound divided into a half million ounces is 31,250 lbs. Good luck taking that much off!

Originally posted by neit_jnf
It is very light for a STOCK wheel, amongst the best!

Bah. The Mazdaspeed 18" wheels (according to Rosenthal Mazda's web site) are 17 lbs, and aren't that much more expensive than the OEM wheels. I know big tractor wheels are trendy these days, but the performance of the car would have been better if they'd just put lighter 17" wheels and tires on the car from the factory. Unfortunately, that's not the style going these days. Just look at all the guys wanting 19" wheels - heavier, poorer handling. Look especially at the guys staggering the wheels with wider wheels and wider tires on the back of an RX-8 - purely for looks, and guaranteed a staggered setup will handle worse than stock.

Regards,
Gordon

Originally posted by Gord96BRG
Bah. The Mazdaspeed 18" wheels (according to Rosenthal Mazda's web site) are 17 lbs, and aren't that much more expensive than the OEM wheels. I know big tractor wheels are trendy these days, but the performance of the car would have been better if they'd just put lighter 17" wheels and tires on the car from the factory. Unfortunately, that's not the style going these days. Just look at all the guys wanting 19" wheels - heavier, poorer handling. Look especially at the guys staggering the wheels with wider wheels and wider tires on the back of an RX-8 - purely for looks, and guaranteed a staggered setup will handle worse than stock.

Regards,
Gordon
I tend to agree. Not only that, but the RX-8 is geared pretty darned high with those 18" on it.

I have had absolutely NO problems hitting 250kmh.

With my 17" winter wheels on I find noticeably better aceleration.
According to my GTech about a quarter second better in the 1/4 mile.

Mind you, a bit more overdrive in 6th would be nice for gas economy on highway runs. I generally drive at about 140kmh on highway 2, and that puts me at around 4500rpm, which makes for crappy mileage.

Originally posted by canzoomer
With my 17" winter wheels on I find noticeably better aceleration. According to my GTech about a quarter second better in the 1/4 mile.Now isn't THAT interesting! 1/4 second is significant. Hmmmm.

Originally posted by Omicron
Now isn't THAT interesting! 1/4 second is significant. Hmmmm.

It is quite significant.

But then (assuming equal tire aspect ratios) it is about a 5% difference in tire diameter.

I just measured my stock 18" wheel and tire and my Nokian WR on the 17" and it is almost exactly an inch shorter.
24.25 x 3.141 = 76.16" circumference
25.5 x 3.141 = 80.1" circumference.
76.16/80.1 = .9508

And it does not cause another shift in the 1/4.
And noticeably more wheel spin on 1-2 and 2-3 gear shifts, meaning less rpm loss.

It all adds up.

Originally posted by Gord96BRG
Bah. The Mazdaspeed 18" wheels (according to Rosenthal Mazda's web site) are 17 lbs, and aren't that much more expensive than the OEM wheels. I know big tractor wheels are trendy these days, but the performance of the car would have been better if they'd just put lighter 17" wheels and tires on the car from the factory. Unfortunately, that's not the style going these days. Just look at all the guys wanting 19" wheels - heavier, poorer handling. Look especially at the guys staggering the wheels with wider wheels and wider tires on the back of an RX-8 - purely for looks, and guaranteed a staggered setup will handle worse than stock.

Regards,
Gordon


My sentiments. Technically, the justification for going to larger wheels stemmed from the need for larger brakes. That is usually not the case for most people on the street of course.

Staggered wheel sizes works on many cars. For the 3rd Gen RX-7, I think the 225/55 coming on the rear was much too small to handle the torque it made down low, especially once you start upgrading. Putting larger wheels and wider tires in the rear did a lot for taming its loose rear end. People who complain about the RX-8 must have never driven one. Same for large displacement engines with gobs of torque down low.

As for us, with our power band, I agree I do not see the benefit of a larger wheel in the rear short of appearance. When my tires go I will most likely put a 245/40 Potenza S-03 in the rear with a 225/45 S-03 in the front on the stock wheels. This is as much as I will go. If they had a performance 17" wheel option, I would probably have taken it as the choice of good tires for us right now sucks.

Just pony up and get the magnesium Mazdaspeed wheels. They only cost as much as a Hyundai. ;)

Pardon my lack of knowledge but, will installing smaller diameter wheels on a car designed for larger ones alter the computer, odometer ect? Will this also diminish traction and ride quality. I do like the overall time improvement though, it's almost like installing a stage 1.

I think people earlier were talking about wheel diameter (minus the rubber). You can use a different size tire to maintain basically the same total diameter (including rubber), so it won't affect the odometer. The smaller wheels will have a larger profile tires, so more of the diameter is rubber. More rubber means they absorb more shock, so ride comfort should be improved, maybe with a loss of a little handling. Lighter wheels will reduce unsprung weight (not supported by suspension), which makes the car much quicker than an equivalent amount of sprung weight (supported by suspension) would.

I am talking about the same profile tires on smaller wheels.
My car runs on winter wheels and tires whcih drop it 1"
The effective ratio is 5% lower.
So, when it shopws 100MPH I am going 95.
So what? Less speedingtickets maybe.
Ride? No worse. Remember the base RX-8 as shipped in Japan comes with 16" wheels.
Handling? As long as the contact patchis the same size. Might take wider tires to accomlish that.
As far as traction goes, depends on which case you desire. smaller contact patch may allow more wheelspin, useful for 1/4 mile times.
But will have negative effect on cornering.
MAybe. More a matter of tire stickiness and road conditions.

Doesn't the tire sidewall being taller, resulting in more flex, affect handling?

Sorry! I forgot about this thread. Thank you for the help guys! If your very serious about draging, this is a great way to do it. I would still keep the 18s for daily driving and make the switch for the strip, some extra sticky rubber or drag tires would help as well, but I have to keep in mind the guys that were killing their transmissions on low psi stock tires! Omicron: your right, like rabinabo said, the thicker rubber acts like a shock giving you a more compliant ride but more body roll in corners.

Yup, about what I figured. Sure wish I could drive one with the 17s on it for a few days, as I'm seriously considering getting aftermarket 17" wheels, and using THEM for my daily nice-road driving. Figure I'll use the 18" factory wheels for snow tires. LOL, is that a switch , or what? :)

I guess, I wouldn't know anything about snow, as I've only seen it once! I'm a native!I think there was another thread about the smaller diameter helping to achieve more gear in the lower rpm range, but you would have to shift more often which sounds like more fun to begin with. Canzoomer stated that the only difference using the smaller wheels and overall diameter is you are going about 5mph slower than what reads on the speedo, so I guess it wont screw with the computer to much!

I was doing a search on the whole stock wheel issue - there are a couple of different posts stating the weight of the stock 18"x8" wheel (21 and 26 lbs). If it is the later, that is fairly heavy unsprung weight - there are a few good looking options in the 15.5-17 lb range that can have a noticable improvement in acceleration and handling. Cut 40 lbs of unsprung weight is ~ a 0.1 sec 0-60 improvement. 2-piece aluminum brake rotor hats on the wheel hub vice iron can save 10 lbs at each wheel as well. Now you are up to 80 lbs of unsprung weight removed. 1 lb of unsprung weight is equivelent to 10 lbs of weight anywhere else on the vehicle. 800 lbs off of a 3000 lb car...

Well I'm new to this community and don't know if you found mods other than Intakes and Exhaust, but I've been able to find pullies already, light weight flywheel, turbo kit in the works, a 20b 3 rotorary engine swap, and a few other things. Here's the web pages I've found.

http://www.srmotorsports.com/RX8-Parts.html
http://www.yawpower.com/
http://www.acostamotorsports.com/rx8parts.htm

I hope some of these websites help you guys out. I haven't even picked up my 8 yet, going to pick it up wed the 18th, but trust me I've been looking around already for performance mods, and body kits and the such. So hopefully ya'll can use these web pages and get some of the parts ya'll want for your cars.

Originally posted by CjsfastSS
Well I'm new to this community and don't know if you found mods other than Intakes and Exhaust, but I've been able to find pullies already, light weight flywheel, turbo kit in the works, a 20b 3 rotorary engine swap, and a few other things. Here's the web pages I've found.

http://www.srmotorsports.com/RX8-Parts.html
http://www.yawpower.com/
http://www.acostamotorsports.com/rx8parts.htm

I hope some of these websites help you guys out. I haven't even picked up my 8 yet, going to pick it up wed the 18th, but trust me I've been looking around already for performance mods, and body kits and the such. So hopefully ya'll can use these web pages and get some of the parts ya'll want for your cars. Nice contribution.... good use of the search too. Pretty unusual for someone new to the forum, so you're definitely starting out on the right foot. :D

All of these items have been discussed in one form or another here too, just keep looking and you'll find multiple threads about them.

In all honesty I'm kinda lazy when it comes to reading, so normally what I'll do is take the most recent topic, read like the last 2 pages and hopefully hit the nail on the head. :D

Greddy SP2 Exhaust....looking for it:D

with all these mods going on you will need an adjustable piggyback ecu that is easy to use and tune fuel and ignition. and for turbo if needed. yes???
we have one here in Australia at Ric Shaw Performance. it has been diccussed before .

Originally posted by shadowcougar
Lighter flywheels are always a great mod.
I am reluctant on underdrive pulleys though. Lighter underdrive pulleys are, in some engines, associated with harmfull engine vibrations that can shorten the life of the engine or simply cause engine failure. This is due to the fact that many aftermarket underdrive pulleys are not harmonically balanced, which, from what was explained to me by some master mechanics (they mainly worked on ford, chevy, and honda engines), amplifies the engine vibrations.
This may not be applicable to the renesis, but its certainly something to consider. Many people use underdrive pulleys without a problem, but some do face concequences... Time to start getting some renesis mechanics in here to comment and enlighten us I guess.

How about some port and polish work? Are there manifolds in the 8 that can be optimized? Throtle body? Correct me if Im wrong ut isnt the Renesis engine internally balanced? If so then it is like my ZX2 motor also, and a lightened pulley shouldnt affect it as much as say, a lightweight pulley on a 5.0l with a 28 or 50 oz. damper on it.

Originally posted by Doug McGill Jr.
Greddy SP2 Exhaust....looking for it:D
In stock now!
Shipping from Canada or Huntington Beach, California.

Originally posted by Pk14
I was doing a search on the whole stock wheel issue - there are a couple of different posts stating the weight of the stock 18"x8" wheel (21 and 26 lbs). If it is the later, that is fairly heavy unsprung weight - there are a few good looking options in the 15.5-17 lb range that can have a noticable improvement in acceleration and handling. Cut 40 lbs of unsprung weight is ~ a 0.1 sec 0-60 improvement. 2-piece aluminum brake rotor hats on the wheel hub vice iron can save 10 lbs at each wheel as well. Now you are up to 80 lbs of unsprung weight removed. 1 lb of unsprung weight is equivelent to 10 lbs of weight anywhere else on the vehicle. 800 lbs off of a 3000 lb car...

Is that right? Where can you find weights for the various rims on the market? Enkei and Team 5 Zigen didn't have any weights on their sites... The same goes for the brake rotor as well...

We've had a discussion of the impact of unsprung weight versus weight removed from other areas of the vehicle and the consensus is that the most benefit will be noticed in the handling side versus outright acceleration.

Wheel weights are not all that easy to figure out from most web advertising. There are a couple of sites that offer weights for specific wheels in a given size, however, the quickest way to figure it out is to pick the wheel you are interested in and contact the reseller or manufacturer directly. The stock wheel (18 x 8) is 21 lbs.

Take a look at Stoptech and Brembo. (Stoptech just came out with a front 2-piece rotor as part of their upgrade kit, ~$2000), and I believe they were advertising ~9lbs less at each wheel.

Pk

Ouch... dem rotors are expensive!

Changing the weight of the vehicle period is mostly good for handling only... unless you can drop the car down to like 2500 ~ 2700 lbs... correct?

Well either way it won't hurt to grab a set of aftermarket rims...

So long as they weigh the same or less than stock and are sufficiently strong to handle life's daily challenges like potholes! Unfortunately, adding unsprung weight with "less expensive" aftermarket rims can adversely impact the handling feel the car provides when stock. Some of those rocks easily are 30 lbs a piece!

whoa whoa whoa. 10 times? Unsprung weight does have a much higher impact than sprung weight, but this is quite the exaggeration. Here's an enlightening calculation:

"
Okay,

I recaculated. The kinetic energy of a non-rotational mass experiencing translational movement is:

Kt = 1/2 *mv^2,

where m is mass in Kg and v is velocity in m/s. For a rotating mass experiencing translational movement, the kinetic energy is:

Krt = 1/2 * mv^2 + 1/2 * Iw^2

where I is the moment of inertia and w is the angular velocity in radians per second. For a 18 inch (.4572 meter) wheel that has all of its mass on the outer rim (worstcase), it has an I of:

I = mr^2 = .0523m

and has a angualar velocity of:

w = 2pi * v / (2pi * r) = 3.03v

where r here is the radius of the 26" wide tire. Substituting back in to the earlier equation we have:

Krt = 1/2 * mv^2 + 1/2 *.0523m * (3.03v)^2 = .7398 mv^2

so Krt = .7398/.5 Kt = 1.480 Kt

Or, stated differently the energy needed to accelerate every 1 lb of wheel weight of an 18 inch wheel is equal to 1.48 lbs of payload weight in the car. I don't know where the "4 times" number comes from.

-Mr. Wigggles
"

1.48 times. Not 4 times. Definitely not 10 times.


If you cut 80 lbs. of unsprung weight, it's like cutting 120, not 800. Big difference.

Honestly, if it was really that big of a difference, 80 lbs of unsprung weight would drop like 3 secs. off your quarter mile. I'd be ALL about limiting unsprung weight....WHO WOULD NEED ENGINE MODIFICATIONS? :)

You'd probably see a LOT more innovation/R&D in the area of lightweight wheels, too, if this were the case.

--Landon

My question is what are the performance advantages of each? If a light flywheel or pulley improves your throttle response does that mean you're going to see your straight line acceleration improve?

I would like to know where the best place is to start if I want to improve the low end torque and overall acceleration.

If I bolt on an indy car intake scoop and tuba sized exhaust is it going to drive my gasmileage into single digits too? I read some of the threads on the ECU programming and the results looked promising but the packaging still seemed immature. Are there any good sites that are doing long term tests on the performance and engine life? What would be the best place to start if my goals are more low end and improved acceleration?

Originally posted by shaunv74
My question is what are the performance advantages of each? If a light flywheel or pulley improves your throttle response does that mean you're going to see your straight line acceleration improve?



Absolutely!!! A flywheel is a very noticable improvement. While technically a light flywheel does nothing to add horsepower it does give you more usable horsepower. In other words while the engine isn't making more power, it is getting more to the wheels. You will definitely notice it.

Well put, Rotarygod. :)

--Landon

I see. thanks RG. So why does the manufacturer not install a lighter flywheel to begin with if it is more effiecient? What are the downsides? I saw mention of reduced drivability. What is meant by that.

People say that a light flywheel is hard to drive on the street. I personally don't find this true at all but I actually can drive good! ;) Seriously though, the lower inertia of a light flywheel will not only cause the engine to accelerate faster but also decelerate faster. Between shifts the rpms will drop a little lower than they would normally. Off the line is the most noticable since it does require a little more clutch slippage to get the car moving. It isn't much more though and I don't feel it is an inconvenience at all. Both of my RX-7's have had the light aluminum flywheels.

Try this, drive around a parking lot in 1st gear. Don't push the clutch in just accelerate and decelerate at a reasonable pace. There may be times you notice the car try to jerk back and forth a little depending on rpms and speed. This isn't a problem if you give it more gas or slip the clutch. This effect will be worse with a light flywheel. It just requires a little different tactic. My logic is that if it only happens when you go slow, don't go slow!

LoL. Like when the patient reported to the doctor "It hurts when I do this" and his response: "Well then don't do that!"

I really dig how you apply technical issues to comprehendible real-life experiences, rotarygod, keep up the good work!!

--Landon

Thanks RG. You have a great way of explaining it. I understand exactly what you mean. I'm still a bit ham footed with the clutch and still getting used to the relative touchiness of the tight friction point and low torque so I was looking for something that would give it a bit more bottom end to make it a bit more forgiving and smoother when starting out in 1st and shifting. I guess I'll just have to get better at driving it. Do you find there is a significant difference in clutch life due to having to slip it more with the lighter flywheel?

I have a dumb guy question...

I've read the 13B has cast iron rotors and sideplates. Why don't they make them out of a hardened steel? I would think that would be lighter and still be able to handle the heat and the loads. If anything I would expect it would be better.

Anyone have any info on that?

I'm kinda late jumping in on this thread. I read about halfway through.

My dad, an ole stock car racer, has buzzed around with me in the car and we discussed this car at length. He read the Wankel Rotary book for interest and then came up with a few suggestions.

1) change the rear (differential) gear

2) provide AC air to engine intake

3) consider exhaust mod but try others first

4)find out what they are doing with that Mazdaspeed version on the management system


Those are his suggestions. I am not familiar with differential gearing but he said that modifying the rear end would make a BIG difference - effect top speed and possibly MPG but a BIG difference. He recently took his Miata in for service and drove a Mazdaspeed version and loved it. Apparently it has a different rear end gearing too.

The rear end ratio for the RX-8 is 4.44:1. The manual transmission RX-7's ran 4.10:1 and they were considered high ratios. The bigger the number, the better the acceleration. The smaller the number, the higher the top speed.

Rotarygod, regarding light flywheels I have noticed that their weight varies between approx 9lbs (ACT) and 15lbs for the MS.
Is the 9lb flywheel too light in your opinion and would it affect drivability too much relative to a heavier 15lb unit such as the MS?

The temtation is to go with the lightest flywheel available for best engine response but unsure of the consequences.

Your informed response would be appreciated

Regards
Rexi

ACT quotes the weight of the flywheel without a counterweight attached. The stock flywheel has the counterweight built in which contributes to it's published weight. Numbers like this are sometimes misleading to help sell more product. I'm not sure if the Mazdaspeed unit has a counterweight figured into that number or not.

I use the 9 lb. flywheel on my daily driven RX-7 with absolutely no problems. I love the way it drives. That weight figure is also without the counterweight.

Thanks Rotarygod

Rexi

I think the rear end has a high enough ratio. If we went higher to improve acceleration the engine would rev at a higher RPM than it already does at highway cruising speeds correct? This would reduce your gas mileage, potentially reduce moving part life, run hotter, yadah yadah. If we take it lower you might gain some top end if the car is not aerodynamically limited but I think ~155 is fast enough. (My opinion) That and with the low end torque the engine has, the car would not accelerate as fast I imagine. Now if people are thinking about FI I definitely think you are right on with changing out the rear end gear. My 5 spd FD ran at a lower RPM at the same speed as my 6 spd RX8! I've read a few threads about rear Differentials failing on people due to bearing retaining rings. If someone has opened up the rear end I'd like to know if they have an uprgrade for this?

I personally am interested in getting some more bottom end in the motor first.

In order to get more bottom end would rather:

a) Buy a turbo kit for about $4,000 and pay another $1,000 or so for install and tuning? In the meanwhile void your Mazda engine and drivetrain warranty.

b) Do the common mods available now... intake, exhaust and ECU... maybe a flywheel also. Not void your warranty... wait until it expires and then FI that bad boy.

c) Spend a little more for new tech intake and exhaust with tuned ECU, flywheel, etc. that claim to improve low-mid power. After the warranty period is up.. FI.

d) Get the new tech intake and exhaust, etc. Play wait and see... if the mods satisfy, stay N/A, if not... consider FI at some point in time.

I would do:

Power mods:
drop-in filter (green sounds good)
full exhaust
ecu
pullies
flywheel

I think these would put me real close or over 230 whp and I'd be happy with that

Handling mods:
Full Mazdaspeed suspension (shocks, springs, sway bars, strut bars, underbody braces)

Visual mods:
Mazdaspeed Nose and mirrors
Factory app package for the rest

Maintenance mods:
Synthetic engine, tranny and diff oils (Royal Purple)
Evans NPG+ with low pressure conversion
High-Temp synthetic brake fluid

I think these would put me real close or over 230 whp and I'd be happy with tha


I dont think that you would get that much HP out of those mods, add the intake and the canzoomer and you probably could

I mentioned an ecu there, you missed it? I'm not sure I would go with canzoomer or e-manage, I like how you can fine tune with the e-manage but also like the ease of a set map with the canzoomer...

I'm thinking that with the e-manage it would be better as I can fine tune for my specific mods.

I agree with RG. The ECU and light flywheel are the way to go first. Let's keep in mind this is a thread excluding intake and exhaust to come up with more creative ideas.

I've seen Aluminum and Steel replacement flywheels both claiming to improve engine response because the the center of mass is closer to the center of rotation. So my question is will the Aluminum be better than a well designed Steel flywheel? My concern with Aluminum is the metal fatigue. Even though they have hardened steel teeth I would be worried about all the Low Cycle Fatigue of continually spooling it up and down. Would a Steel flywheel, that may weigh more, perform just as well as long as it was designed with most of the mass far enough inboard that the moment of inertia is the same? Is this possible or are the strength to weight properties not there? Are there Titanuim flywheels out there that would be the best of both worlds...+$$.

Thoughts on flywheel design...

Speed magazine mentions a Carbon Fiber flywheel for the MSP RX-8 but I think it's a typo

Originally posted by shaunv74
I agree with RG. The ECU and light flywheel are the way to go first. Let's keep in mind this is a thread excluding intake and exhaust to come up with more creative ideas.

I've seen Aluminum and Steel replacement flywheels both claiming to improve engine response because the the center of mass is closer to the center of rotation. So my question is will the Aluminum be better than a well designed Steel flywheel? My concern with Aluminum is the metal fatigue. Even though they have hardened steel teeth I would be worried about all the Low Cycle Fatigue of continually spooling it up and down. Would a Steel flywheel, that may weigh more, perform just as well as long as it was designed with most of the mass far enough inboard that the moment of inertia is the same? Is this possible or are the strength to weight properties not there? Are there Titanuim flywheels out there that would be the best of both worlds...+$$.

Thoughts on flywheel design...

On my RX-7's I have had both the aftermarket steel and aluminum versions. My favorite is by far the aluminum and it is what I currently have on my 1st gen RX-7. Both units are an improvement over stock. The aluminum is just more of an improvement. The car revs much faster. It is racecar quick by comparison to the stock flywheel. This is very noticable in acceleration as well. There are no issues with a change in gas mileage. If it does change, it goes down beause the car is so much more fun you are flooring it everywhere. It isn't a good choice for drag racing but neither is the RX-8. For drag racing just keep the stock one. Most close drag races are won or lost at the starting line.

The aluminum does not have any issues with fatigue. They have replacemable friction surfaces which make them very good for long term use. The teeth only get used at startup for a few seconds and even then at a low rpm. Otherwise they are just spinning freely. Any flywheel should not be taken over 10,000 rpm though as this is where they start to get dangerous.

Just curious... why shouldn't flywheels be taken over 10,000 rpm? If so, what do F1 racecars use? What about your average 1000cc and below motorcycle (15k redline!!)? I know that a motorcycle is a bit different technology and the gearbox is entirely different... but the F1 racecar?? AND with the 8 reving to 9,500rpm... 10,000 is you have a limiter cutter (JDM piggybacks)... isn't this dangerous?

Speed magazine mentions a Carbon Fiber flywheel for the MSP RX-8 but I think it's a typo

That was definitly a typo.

The aluminum does not have any issues with fatigue. They have replacemable friction surfaces which make them very good for long term use. The teeth only get used at startup for a few seconds and even then at a low rpm. Otherwise they are just spinning freely. Any flywheel should not be taken over 10,000 rpm though as this is where they start to get dangerous

Thanks for the definition on that one RG. I'm guessing you'd have to precision balance a flywheel over 10K or make it out of stouter stuff because it starts to creep?

A race car or a motorcycle are totally different. Manufacturers don't typically worry about car flywheels spinning over 10000 rpm because no street car revs over that. I'm not saying that you can't take one over that. Manufacturers just don't recommend it. Stress increases exponentially with an rpm increase. At really high rpms you run the risk of a flywheel or clutch exploding if there is alot of stress on them at that point. If you are this high in rpm you are probably racing and putting alot of stress of the car. If you want to run one this high it is extremely advisable to use a ballistics scatter blanket or shield so that flying metal fragments don't pierce your floorboard and potentially sever your legs. I personally like knowing my feet are attached and fully functional.

Race cars have components that are desinged for these stresses. F1 cars idle at 7000 rpm and rev to about 18000 rpm. I definitely wouldn't try that with any street car. Motorcycle components are much smaller. There is far less inertial stress on the same materials at the same rpms. Since they are smaller in diameter, their weight is concentrated much closer to the rotational center. Inertial loads also go up exponentially with distance from the rotational center.

Thanks RG... it was actually the answer that I expected.

How about plug wires from Nology or Autoexe?

http://www.vividracing.com/catalog/index.php?cPath=17_18_1053_1207&osCsid=8ff784cc8b015ed1e2844d87d3422c5b

Read this whole thread..... http://www.rx8club.com/showthread.php?s=&threadid=27230&highlight=ignition

Thanks for the link to the thread. Still unlclear to me what if any benefit there is to just the plug wires alone.

As I said in the other thread about plug wires with ground built-in... nothing prove via dyno, etc. But the but dyno and my ear say there's an improvement. NOTE... this comes from my experience with them on a motorcycle.

Quicker, stronger response, stronger, stable idle.. more torquie. Where I couldn't pull wheelies with out a lot to WOT, now I could pull them easily under partial throttle (only a 400cc bike).

These gains are similar to what all the different manufacturers claim as well. Thus what gains, if any, should be perfectly clear. The question is just, do you actually get any gains and how much...

Nology Hot Wires...

Nology HotWires are the most technologically advanced ignition wires available. HotWires create the most powerful spark possible. HotWires are engineered with a special built-in capacitor, exclusive only to HotWires. This revolutionary design allows energy from the ignition coil to accumulate in the capacitor until the voltage at the spark plug electrodes reaches the ionization point. At that split second point the entire power of the stored spark is discharged at once, creating a spark 300 times more powerful. The result is faster, more complete combustion, and most importantly, MORE HORSEPOWER that's 100%. Smog Legal.

The capacitor feature sounds intriguing to me. The logic and results on their website sound solid. :cool: Can someone back this up with personal experience in a car? I've heard arguments that drag racers like a slower burning flamefront so they have a longer power pulse rather than a shorter one? The Nology concept is counter to that theory. The website says to call about getting them for the '8. Has someone tried these out.

Only on my 400cc motorcycle. There are people on the SVRider forum who have also tried it on their 650cc and 1000cc bikes. Everyone reports similarly... low-end torque is noticiably stronger. I'd do new plugs at the same time that I install the wires.. in order to get full effect.

For Plugs... FEED says something about having high performance RX-8 only plugs...

After looking under the hood today at where the plug wires are positioned I think it would be easier to swap out the flywheel than the spark plugs...:eek:

According to comments by Mr. Fujita (FEED), NGK has released iridium plugs for the RX-8 (which are different than the iridium plugs used in the RX-7). They cost 3600 JPY each and he recommends #10 Trailing and #9 Leading.

He also mentioned in terms of maintenance, if you're going to run your RX-8 hard, the first thing to worry about is the transmission. He believes that the syncros are weak and will wear out after several thousand km of abuse. His advice is to let the transmission warm up before putting it through the paces, and change the oil to Narashi(?) type transmission oil.

HKS is also releasing RX-8 type plugs and at the Tokyo Auto Salon 2004, promises to be releasing more RX-8 parts (as they are mvoing more into the rotary world).

Maybe Narashi is the Japanese name for "Royal Purple?" :D

Could be. I can't get a translation of it other than "Narasimha " and "Narasimhan" as a person's name.

Either way, I'd say as soon as you can, drain the stock oil and put in quality synthetic transmission oil.

Also SEVERAL of the different shops (RE Amemiya, Knight Sports, FEED...etc.) offer special "rotary oil." Runs about 8,000- 12,000 JPY and many are 100% synthetic or half synthetic.

That was a joke. :D

yeah.... I kinda thought that. But I am serious thinking that its some kind of synthetic tranmission oil or a PFTE lube...

while we're talking about various engine mods...what exactly would be the point of buying a coolant tank cap that raised the pressure from 0.9 to 1.3?

raises the boiling point of the coolant, so you can run a higher temp without worrying about getting gas pockets in the line (which then prevent collant from being pumped around, quickly overheating and killing the engine). this also puts a higher heat load on the engine, and a LOT more stress on your collant system components, but in a race car is sometimes quite necessary to run the right temp knowing that you're gonna replace your components more frequently.

Originally posted by wakeech
raises the boiling point of the coolant, so you can run a higher temp without worrying about getting gas pockets in the line (which then prevent collant from being pumped around, quickly overheating and killing the engine). this also puts a higher heat load on the engine, and a LOT more stress on your collant system components, but in a race car is sometimes quite necessary to run the right temp knowing that you're gonna replace your components more frequently.

so, then, the potential negatives outweigh the positives for a car that is just a daily driver/weekend auto-xer...

I still don't have an 8 but thinking of getting one .. My problem is that where im from there are none whatso-ever performance shops or dynos :mad: so everything that I would buy for the 8 must be installed by me.. and most of the things you guys said are about porting/polishing, balancing ... things I don't think I can do at home but exhaust/headers/CAI/UDP I think I can.

If I bought a ECU for da 8 could I tune the car manually or do I HAVE to get it to a dyno (no dynos whatso-ever)??? and what other things could I do??

I would wait until there are more parts available. It's up to you whether you want to buy the car or not. If you do, you can join the rest of us in waiting for the aftermarket to open up. It takes patience, but it's worth it :). If you did buy an ECU, the best way to tune it right now is through the e-manage or the CZ ECU, which is similar to the e-manage. Tuning an ECU is not easy. I commend you for your DIY attitude :).

If I bought a ECU for da 8 could I tune the car manually or do I HAVE to get it to a dyno (no dynos whatso-ever)??? and what other things could I do??Get yourself a GTech Pro Competition model. No, they are not as accurate as a dyno, but they will allow you to measure improvements mod to mod.

I don't live in the US im from Saudi Arabia, ME. hmmmm what can I say?
people here truly suck when it comes to car performance.

for example: What they consider a REALLLY REALLY REALLY tuned car is a car thats:

1-Tinted
2-Wheelz
3-suspension upgraded
4- .. and other ONLY cosmetic stuff

So I can't wait for the parts to come out... cause there never gonna be out here!
thats why im gonna try ordering all my parts + me installing them.
Soo whats a GTech Pro Competition model and how can I e-manage.

(stil don't have the car but HOPEFULLY gonna buy it in about 2-3 months)

thanks in advance..

There are plenty of other threads on the board on intake and exhaust so please keep this one on some of the other great ideas I've been seeing.

I just installed the Racing Beat Aluminum flywheel this weekend. It's great! I love it! There are no drivability issues and I am not a boy racer. I actually think the clutchwork is more positive due to having the clutch material on the flywheel and the clutchplate. I left in the stock clutch since it barely has 15K on it. The car feels lighter and more responsive. It's a 9.5lb flywheel with a 3.5lb counterweight so it's 13lbs total. It's more responsive through the revs and you can feel it pull harder as it comes up the torque curve. Kind of like the difference between driving the car alone and when you have the weight of a passenger or two onboard. I highly recommend this as a good first modification. The only bummer is while you're down there with the cat and tranny out of the car you think about how easy it would be to do a bunch of other stuff at the same time.:-P

There are plenty of other threads on the board on intake and exhaust so please keep this one on some of the other great ideas I've been seeing.

I just installed the Racing Beat Aluminum flywheel this weekend. It's great! I love it! There are no drivability issues and I am not a boy racer. I actually think the clutchwork is more positive due to having the clutch material on the flywheel and the clutchplate. I left in the stock clutch since it barely has 15K on it. The car feels lighter and more responsive. It's a 9.5lb flywheel with a 3.5lb counterweight so it's 13lbs total. It's more responsive through the revs and you can feel it pull harder as it comes up the torque curve. Kind of like the difference between driving the car alone and when you have the weight of a passenger or two onboard. I highly recommend this as a good first modification. The only bummer is while you're down there with the cat and tranny out of the car you think about how easy it would be to do a bunch of other stuff at the same time.:-P

I've been wondering about this flywheel from RB (especially since the company is located about 30min. from where i live :)). Is it that much of an improvement over the stock flywheel?

I would just like to get more power out of my 8 with low-key (sleeper) mods. Actually, i'm wondering if there is anyway to get more torque out of the 8. 125ish Lbs. torque at the wheels is kinda a bummer ya know?

I have the SR Motorsport lightened flywheel. It helps the engine rev up a bit faster. Doesn't give hp gains, just makes the engine a bit more revvy. Actually take away a bit of torque feeling (that is before I got my turbo). Sorry, for low end tq. you are really looking at nitrous or turbo.

I have the SR Motorsport lightened flywheel. It helps the engine rev up a bit faster. Doesn't give hp gains, just makes the engine a bit more revvy. Actually take away a bit of torque feeling (that is before I got my turbo). Sorry, for low end tq. you are really looking at nitrous or turbo.

so you're saying that in order for me to get more torque, i gotta shell out like 5k on a turbo/nitro kit for my ride?

If you want low/midrange tq, then yes. If you want some extra high end tq, you can get something like a Canzoomer unit that will allow you to adjust air/fuel ratios & timing, but has shown the greatest amount of improvement in the 7000-9000 RPM range.

hmmm.....bummer. I was most interested in the low end torque. I feel this is where performance matters most when picking up speed. That's just me though.