Psylence

shadowcougar, good point..

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

Turborex

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.

Buster77

yeah, what he said...

rotarygod

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

shadowcougar

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...

Omicron

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?

Jason

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

Red Devil

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

Omicron

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?

rotarygod

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.

Omicron

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...

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

Red Devil

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.

Omicron

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

starstar5

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.

Turborex

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!

Turborex

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

Omicron

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: https://www.rx8club.com/showthread.p...threadid=11614 It's really long (28 pages last I checked) but is a fascinating, and worthwhile read.

s13lover

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.

Omicron

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...

wakeech

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).

rotarygod

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.

Omicron

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

Buster77

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.

Omicron

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?

djmano

Omicron,

Here's the link: https://www.rx8club.com/showthread.p...5&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.