i was talking around the shop today and we are all pretty confident that we should attempt it.

my question is: who on here would buy a complete renesis 3 rotor kit if it were available for lets sayyyy... 15 grand, if it put out 300+ N/A? a stock 20B can put about 230 in N/A form and can pretty easily reach 300 with some mods. the renesis already puts out 180 in N/A form, so 300 shouldnt be too far of a reach, if one at all.

it would probably cost a very experienced rotory shop a good amount of dough to install it as well. unless we decided to install them.

i just want to see who would be interested.

For that kind of money, I would send my car to rgonza (http://www.rx8club.com/showthread.php?t=78088)

Yeah, I know this is probably completely unrealistic, but I would pay ~$12 (parts and labor) to get an RX-8 to 300whp+. Of course, having a turbo in addition for that low-end kick would be better. I know I could get better cars for that price and blah blah blah -- the RX-8 is the car for me.

My main problem is that I wouldn't want to void my warranty. If I knew a dude that ran a rotor shop down the street then it might be different. I'd feel confident that things were done right and that problems could be handled without a huge cost (maybe just parts or something).

But yeah, rgonza got to 650whp with minimal turbo boost for well under that price (parts only). Granted he's in PR so it's not exactly down the street, but it's still awesome.

I think I would make the sacrifice.... So I would say yes

15k? nope

I'd rather buy a nicely built, 300-400 WHP FD for that cost and have both...

$15g installed I'd consider it... depending how much I could sell the stock motor for

I'm with abbid on this one.

I'd rather buy a nicely built, 300-400 WHP FD for that cost and have both...
me too but 400 is gonna cost you alot more than 15. my FD alone was 15 with 40k on it. a friend of mine spent 24,000 (not including the car) getting his FD safely to 400 at the wheels.

who would do it for 12 grand?

As the club president of the 3-rotor dreamers club I would be REALLY interested in this, but like everyone said (and as president of the cheap modders club) 15K is a little steep.

Can I offer a suggestion...two possible alternatives:

(1) You sell a DIY kit that gives the customer all you need to build a 3 rotor with his/her own Renesis as the major parts source

(2) You bring in the customers 8 and build it for the customer by using as much of the customers Renesis as possible

Both those option would keep cost down and bring you ALOT more customers! :SHOCKED:

According to the initial post, the $15k would only be for the kit, not the actual install. The total cost would be completely absurd for the hp gain.

According to the initial post, the $15k would only be for the kit, not the actual install. The total cost would be completely absurd for the hp gain.

its cheap considering a professional install of a 20B into an rx7. last i heard Peter Ferrel charges about 35 grand for a 20B conversion into an FD. your looking at a completely new subframe, intake and exhaust manifolds, ecu, cooling system... the list goes on...

300 is just a guess, it could be alot more than that, nobody knows. its never been done. i know its quite easy to reach 300 in a conventional 20B, so honestly, i believe the renesis will yield much more than that.

i think 12k (which is also an ESTIMATE) is pretty reasonable. your getting 300(+)hp thats all motor, no turbo, no boost guage, just power. IMO, id rather spend the money and have 300hp that i know is going to last years and years, rather than spend half that, double my hp, and have to rebuild every six months. more boost = more problems. keep it simple. and if you REALLY wanted to spend some cash, you could still slap a huge turbo ontop of things later down the road.

im not trying to argue or anything, but theres alot more to good power than just dyno numbers. i do understand that everyone spends their money differently, and i respect that.

i shudder to think of the inverse relationship that HP & gas mileage have on a 3 rotor engine...

Too expensive

i shudder to think of the inverse relationship that HP & gas mileage have on a 3 rotor engine...

There are ways to lessen the blow, like going from 4.44 to 4.11 or 3.90. Not sure its possible but with 300+ HP our gearing doesn't have to be so aggressive.

i shudder to think of the inverse relationship that HP & gas mileage have on a 3 rotor engine...
gtorx7 on the rx7 forums has a street ported N/A 20B that has all customs manifolds and he says he gets around 17-18mpg with a few trips to redline every time he drives. he pushes 315 to the wheels and has P Ports that havent even been opened up yet.

this car is HEAVILY modified for drifting. the 20B renesis we build will be designed for everyday use in an everyday rx8 (or rx7). the gas mileage on a renesis is MUCH MUCH better than the previous 13B or 20B. the side exhaust ports completely eliminate port overlap, improving efficiency greatly.

http://www.rx7club.com/attachment.php?attachmentid=127087

http://www.rx7club.com/attachment.php?attachmentid=127119

15 grand w/out install isn't worth it, you can probably put a covette engine in there for less money and you get twice the power and twice the torque. I know it's not a rotary, I'm just comparing what you could get for the same price.

I think it'd be cool to see if it could be done though, it's an awesome project, and then mazda might get smart and make a 3 rotor version.

and if we get really lucky we might see a mid-engined 4-rotor mazda supercar that would be something like the NSX... only with a rotary... *droooool*

15k no. 12k no. thats just too much to spend for 300hp, especially if that doesnt include installation.

I love the idea. I cant afford the price but it is the first step toward an 4- rotor Renesis and that would be worth seeing. I dont know if this is feasable, but why not build a first 3 rotor renesis and then attract customers from that. People are turned off to the price but i think its becasue they have yet to see any form of results.

for 15K you get a 20B installed and running in a 8. That is with your choice of turbo and tuning.

Now, it be nice to show Mazda what a 3 rotor renesis can do.

wow 12k... thats a hard pill to swallow. But well worth it, collectively i've already spent that amount on mods.

A 3 rotor n/a is a great idea and something I have been considering for a while now. Of course, for that price you can find other means to make that kind of power but the 20b just sounds incredible. Plus, 300whp without a turbo would get a lot more respect and you can always add a single turbo to the 20b if you want 400+.

My only gripe is the fact that the renesis is still in the early stages of FI and I feel that ditching the renesis is not giving it a fair chance. I really like the renesis for what it is and it really depends on what goals you have. I think that 300whp will be enough for a 12 second 8 and that is enough power for a street car imo. If you want astranomical hp, then the 3 rotor is the best way to get it but I believe the renesis is more then capable for all our 300whp goals.

for 15K you get a 20B installed and running in a 8. That is with your choice of turbo and tuning.

Now, it be nice to show Mazda what a 3 rotor renesis can do.

Unless you do all the work yourself you're not going to get a 20b swap done for 15k.

Unless you do all the work yourself you're not going to get a 20b swap done for 15k.


sure you could. The 20b swap is wayyy easier with an rx8 then an fd(more space). Plus, it's not an exotic swap like it use to be. In a couple more years I can see this swap done for even less.

I hope we don't discourage them, I think they can tell that this is a universally loved idea. I prefer NA power which is why I'd love to entertain the idea of a 3-rotor Renesis but the price is just not at the sweet spot.

drivelikejehu...how about my idea's to bring down cost? Please please please make this possible.....just thinking about it.... :Eyecrazy: :shocking: :crazy: :Drooling_ :icon_droo

I hope we don't discourage them, I think they can tell that this is a universally loved idea. I prefer NA power which is why I'd love to entertain the idea of a 3-rotor Renesis but the price is just not at the sweet spot.

drivelikejehu...how about my idea's to bring down cost? Please please please make this possible.....just thinking about it.... :Eyecrazy: :shocking: :crazy: :Drooling_ :icon_droo

oh dont get me wrong... it WILL be done. now selling kits was just an idea, and the purpose of this thread is just to kinda see who would actually want to buy something like this. no offence to the rx8 owners out there, but its a much older crowd, and the majority of you arent looking for (or need) something like this.

im not trying to keep this a big secret, but rather progress rotary technology. if anyone has ideas suggestions or solutions to problems that are unforseen at the moment, feel free to give your 2 cents. hell, since we dont have an 8 at the moment to put this engine into, if anyone would like to volunteer their car to be the first you would walk away with the worlds first true 20B renesis... for free.

sure you could. The 20b swap is wayyy easier with an rx8 then an fd(more space). Plus, it's not an exotic swap like it use to be. In a couple more years I can see this swap done for even less.

It may be easier but still requires many hours of work and custom fabrication. I'd be shocked if you can find anyone in the US to do it for less than 25k, doing it yourself you could probably do it for about 10k. Either way you had better have another car, or be able to walk everywhere you want to go for a while...

^and that is one of my main problems with stuff like this. First, if my 8 is a near brand new car and I just could not give it over to be wacked at....GOD HELP ME if they couldn't build it back the way it was. 2nd....what in the world would I be driving to get to and from work?

Other than that...I would love to turn my 8 over to these guys since it's well known how much I would want such a engine.

^and that is one of my main problems with stuff like this. First, if my 8 is a near brand new car and I just could not give it over to be wacked at....GOD HELP ME if they couldn't build it back the way it was. 2nd....what in the world would I be driving to get to and from work?

Other than that...I would love to turn my 8 over to these guys since it's well known how much I would want such a engine.
sacrifices have to be made somewhere...

but this gave me a sweet idea. what if instead of selling them to normal people... i build one into an rx8, then drive that damn thing to mazda headquarters and be like "look fags, the shit is possible, now DO IT! and give me a job..." then we will have 3 rotors out of the factory... again. :)

It may be easier but still requires many hours of work and custom fabrication. I'd be shocked if you can find anyone in the US to do it for less than 25k, doing it yourself you could probably do it for about 10k. Either way you had better have another car, or be able to walk everywhere you want to go for a while...
Ike that is a good point but if some one was going to do this trust me, they will have another car. This is not your weekend motor swap. I think most of us know this.


When i was looking into doing this, I already had the motor from my FD that I was planning putting into it. The engine mounts, turbo manifold, fuel rails with injectors (1000 cc x 3 and 1600cc x 3) with FPR and s/s lines, was going to run me $1800 from Rgonza . The sub frame mods are minimal, just some triming but it doesn't required to be replaced or hacked which is cool because is reversible.

I wish you were on my side of the continent, I be the first one to volunteer.

i would be interested...not for 15 grand though

sacrifices have to be made somewhere...

Yeah I know…if I was single it would be easier for me to do, I hurt only myself but with family (and a new baby) I can’t make such an irresponsible decision that impacts my family in general.

If you never end up doing this, once my 8 is paid for I’ll be knocking at your door.

By the way, how far along are you and what’s your companies’ background/history? Any links? Any previous projects you could give us more information on?

Again…I’d love to be Guinea pig #1, but I just cant’ afford to be. Maybe some of our “well off” members wouldn’t mind turning over their 8’s???

I’m probably dreaming…but wouldn’t it be cool to build a 3-rotor Renesis (change the gearing to 4.11’s or 3.90 instead of 4.44) making 300whp drive to Mazda’s HQ and tell them that you still got 18/24 so they have no excuse on not building a 3-rotor.

I’m such a dreamer…

By the way, where are you located?

I can see how this can be done but not sure if it will work. Parts that are needed is another housing, middle plate, new header, rotor and a 20b e-shaft. Then the hard part of making the intake manifold. I haven't looked at the stock one but I know it is plastic. I wonder if it can be slipt it in half the make a custom upper intake manifold (where they all merge at). then ECU the ECU is anothe issue on its own.

I think that 15k is a little steep for the returns. However, a little decrease in the price gains a disproportionate amount of interest in a 3-rotor Renesis.

Parts that are needed is another housing, middle plate, new header, rotor and a 20b e-shaft. Then the hard part of making the intake manifold.


he mentioned all the other bits. and of course an intake manifold would be part of the "kit"

.....and if you complete it and show it off at Mazda HQ, you should probably drop the "Hey Fags...." opening from your presentation - may rub them the wrong way (no pun intended, of course.) :mdrmed:

S

he mentioned all the other bits. and of course an intake manifold would be part of the "kit"
But I don't see it adding to 12k

^yeah, that's what I want to know...how does the custom parts come to 15K in price? If you use most of your current 2-rotor Renesis that should cut cost down significantly.

Not for 15K. Basically, I'd need justification why it's more worthwhile to spend money on more displacement when I can keep my current displacement, spend the same amount of money and produce more power.

I'm curious how you would solve the exhaust port configuration issue with fitting an extra rotor. I'm sure it's possible, but that's a lot of trial and error and custom machining.

edit: I do think it would be very cool and worth considering if it was offered, though.

15k for 300 hp lol... give me 1k and i'll fly to your hometown and punch you in the mouth. That way you'll save 14k and the embarassment for spending 15k for 300 hp.

For 15 grand I'd go with either a ls7 conversion to 500 hp NA or do a 3 rotor 20b turbo setup.. If it was closer to 5-6K i'd consider it... You can grab a rebuilt 20b for about 4k. The rest of the cost is labor and custom work.

In short, no I personally would not pay 12K or 15K for parts alone to do this.

I'm happy enough with my 8 the way it is, no desire at all to pay that kind of money. I'm not sure I would've even paid an extra 15K to have had it as an original, installed factory option. Maybe $10K.

So, as you can tell the 15K price tag is way too high.

A kit for 5-6K seems to be the sweet spot for such a product. Of course, initial price would be higher since you all would try and recoup the R&D.

Can someone tell me then why Acosta charges arm, leg, internal organs, and future children to make a 20B Turbo? They must sell like 1 per decade at that price.

How is cooling going to be upgraded? How are the oil coolers going to be upgraded? What coils, ecu setup, etc are going to be used? It definitely won't pass inspection anymore. Is traction control going to be gone? (I'll say yes to that one) How is oil metering going to be dealt with? What clutch is going to be included? Is the fuel system going to be upgraded? Is there a battery relocation kit included? Is there a new intake included? How is the exhaust going to be upgraded? What oil pump will be used? I could go on...

I haven't even gotten to the actual engine yet. How much money would be tied up with the above items? How much time would be tied up making thse changes and how much does shop time cost per hour? Let's get to the engine. You will need to have a custom cast and machined front intermediate housing which will cost quite a bit up front. You'll either have to acquire a supply of 20B eccentric shafts and counterweights which would get expensive or machine your own which also wouldn't be cheap or easy. Then you'd have to get it all balanced with the Renesis rotors which again takes time and money.

If this could all be pulled off for $15K, it would be a bargain. However I don't see it happening and even if it could, I don't know many that would pay that much for a 300 hp engine. It would be cool though.

RG :balls: rx8wannahave

lol :p:

I thought the greatest issue with the 20B was the E-shaft. Maybe this project could be made financially viable by using alternative materials for the E-shaft, and making them available as a 20B upgrade as well...

^alright thats alot but im going to try and answer as many of those as i can. oh yeah i just to clear up anything, 15k is just a very very rough guesstimate, and would be an entire new motor and everything you would need to install it. we would take your core though.

rotarygod: good questions! many of those questions youve asked are the basics of a conventional 20B, so look there for some of them.

as for the intermediate plate: we solved that issue today in the shop and soon we will begin an aluminum mock up to be molded, then the actual plates can be casted, then the faces machined. no big issues there.

intake: this is actually the largest issue in itself, because it contains alot more than just the routing of air into the housings. the hardest part is controlling everything electronically (new ecu), which isnt my department in this project, but my boss says its doable so ill just leave it at that.

shop time: free, its our shop.

clutch: we dont know yet because we dont know how much power its going to put out. obviously more power needs a stronger clutch.

emissions: something we also have thought about, but we need to first build the engine, then actually test it. this is also up to the person who is going to be using it. if your desire is pure dyno numbers, then im sure your going to have no cats and strait through exhaust, in which case you wont pass. if you are looking for more power without rebuilding every six months or staring at a boost guage 24/7, then im sure you are going to leave some sort of cats on, and you still could pass. who knows.

e-shafts: yes these are expensive and are the majority of the 15k tag. supply is not the issue since there are many aftermarket makers of them. and if we REALLY wanted to spend some time, we COULD make these, but thats not our concern right now.

just keep in mind we arent trying to build a track engine here, but a daily driven engine, with more (maybe much more) power, without sacrificing reliability. N/A 20B's are just as reliable as their 2 rotor counter parts. 300hp is a guesstimate, and as you can see the project is already starting to take wind, so we should know soon.

i think i adressed most things, let me know if missed anything.

rx8wannahave: we are located in the DC area. as for work our shop has done: alot of rollercoster and theme park stuff. the best example of what we've made that you may be able to relate to is a motion base. have you ever gone into one of those 3D movies where you and 20 or so people are strapped in like a roller coaster, and the entire things moves around with the movie? 36 of them were designed and made by my boss in the 90's (before my employment here). they sold for a quarter million each, so im not talking about the cheap ones. these things are HUGE, and could push you at over 6 g's of force in the x y or z plane. i can get some pictures if you want.

for that money i would do a low boost turbo and add water cooling system so that it can boost for long periods of time with less heat probs. for track use of course. :)

If you have access to cheap or free materials and machining, you're way ahead of the curve. That's a big expense. I'd definitely like to see it done. It'll take someone with this knowhow and ability to be able to pull it off. If you do successfully cast a Renesis 20B front intermediate housing, I'll buy one off of you. I'm going to throw a Renesis into my RX-7 but a 3 rotor would be nice.

1 thing: Please, whatever you do, do not siamese the exhaust ports!!! Avoid doing this at all costs!!!

Sorry for reposting this from the other thread, just thought its the same topic, so why not :) , copy and pasting:


What about a 4 port per rotor renesis, 2 rotor renesis is 3 ports per rotor

2 end plates would be stock, and the 2 middle plates you'd fab up and have 4 circular intake holes in it and 1 exhaust port, since you are machineing so many parts, you might as well create a new 3-rotor-renesis with 12 ports that can rev even higher!, instead of using what mazda have, why not improve on its design, dont know if more port # is better tho

http://img223.imageshack.us/img223/4691/untitled29xs.png
________
Vaporizer wiki (http://vaporizerwiki.com)

:rock: Fuck Yea!!!!!! im always up for more power

What about a 4 port per rotor renesis, 2 rotor renesis is 3 ports per rotor


i compltely agree with this... but that falls on the R&D side of the fence. if we can get the "mazda" version of the renesis to work, im sure we will explore other paths further downt he road.

rotarygod: what exactly do you mean by siamese -ing the ports? putting 2 holes for one rotor and one slot for the other on the intermediate plate?

rx8wannahave: we are located in the DC area. as for work our shop has done: alot of rollercoster and theme park stuff. the best example of what we've made that you may be able to relate to is a motion base. have you ever gone into one of those 3D movies where you and 20 or so people are strapped in like a roller coaster, and the entire things moves around with the movie? 36 of them were designed and made by my boss in the 90's (before my employment here). they sold for a quarter million each, so im not talking about the cheap ones. these things are HUGE, and could push you at over 6 g's of force in the x y or z plane. i can get some pictures if you want.

Yeah, I know what you mean...those things are FUN. Your company also built 20B's right...or what I'm getting at is what type of automotive/engine experiance do you all have. I'm not questioning your ability, so don't take that the wrong way, I'm just trying to learn more about you guys.

In DC huh, I'm going up to Virginia to visit my wife's sister and I always take a drive up to DC. If you guys are still working on this mind if I stop by and take a look at what you are up to? I don't know if your working on this hush hush or something, so it's cool if I couldn't see the work in progress.

I'm going up in May-June...maybe you will be done by then or maybe not?

Again, I don't know if your work is hush hush but picture of the progress in parts would be GREAT! But...I understand if you can't.

Thank you for working on this...because of the cost I might never be able to get this but like RG stated you might have more than one product here (4-rotor, custom rotary, do-it-yourself kit, etc etc) and I think this makes alot of business sense for your company.

Also, like stated the people building planes really like the rotary engine so that might be another future application/product.

Thanks and please keep us updated as much as you can, it's fun hearing about the work your company is doing.

Come on RG and driveslikejehu...let's have a 3-rotor group hug :grouphug: (LOL)


Note: By the way, you said you are building this thing and only need an 8 to stick the engine in. Does that mean that if this fails...you could simply stick the original Renesis back in there...no harm done? Or, do you have to take apart the original engine to build the custom 3-rotor.

I can't help but wonder if taking parts from an existing renesis is really the way to go.

ie, (Cost of 100% new engine, minus the sale value of still-intact renesis) versus (Lesser cost of a cobbled-together engine, and a bunch of leftover parts that won't be worth much)

edit: one question. If the plate is aluminum, are you going to have to plate it with iron somehow? Aluminum piston engines have iron sleeves (or that nikasil stuff), is that something you'll have to do on a rotary as well?

a fantasy forum would be a lot less expensive ... :cwm27:

doing a 20b conversion is really expensive even if you do it your self, you dont know how much it is involve until you do it! and if you want to make it NA it is even more expensive since you got to make headers and put NA rotors in it, I can list the parts but it is in the 10,000 to 12,000 just in parts.

and that is without going over board buyng stuf.

I would really REALLY like to see a blog made of this project, I normally hate blogs but I'd read that one.

how about moly plating the rotors? GM has moly plated it's ecotec engine if I remember correctly and that would really help if you want to make the seals tighter and reduce losses thru there.

I still wouldn't pay 15k for it, but I sure as hell am interested in the project.

rotaries for airplane engines is probably where you should focus your market, more than auto engines, they are far superior to the piston engines they'd replace. You just need to market it.

Wow keep up dreaming :boring:

we came up with an idea in the shop today to keep cost down.

since many of you are concerned with the initial price, and the gas milage (although not that bad) that would follow this conversion, a cool idea emerged...

WHAT IF the third rotor was only active under heavy throttle? and only 2 rotors were active under normal driving conditions. this would be much much easier to design AND control, because the stock engine could be left almost completely alone, except for the exhaust manifold. imagine a 20B with a 2 rotor intake manifold on the rear 2 rotors, and a second intake manifold on the front rotor, with a completely separate throttle body and control.

gas milage would be the same as it is now, since 90% of the time, you wont be using that 3rd rotor. but when you want the power, its there. the rotor will already be spinning at the same speed as the engine, so barely (maybe one rotor revolution at the most) any lag.

this would only require you to ADD a manifold, rather than replace the entire thing. you would also be able to keep all of the little mazda tricks that they added into the intake system, without us screwing around with it. this would keep the cost down considerably.

ECU would also be much much simpler, because we could basically just add onto the existing ECU (i just found out today we have that capability) for the third rotor.

to keep the thrid rotor from putting an extra load on the engine, the thrid rotor housing would have to be modified slightly. but this is an addition to the engine anyway. when the third rotor is INACTIVE, we would keep the intake completely open, and add a valve on the spark plug side of the housing (much adding trailing spark plugs to a race engine) and leave the valve open, so the rotor doesnt compress any air, just spins around like its supposed to. when the rotor is called however, this valve will close and normal firing order abnd compression will begin. like before, one rotor revolution may be lost in the transistion, but thats nothing in the scheme of things.

the only issue with the design of this is controlling the oil spray into the chamber for the apex seals, since the rotor wont be combusting, the oil wont be burned... but im sure we can come up with something. or maybe someone else can.

just imagine cruising down the highwayin 5th gear... then you drop it into 4th (or 3rd if your really tryin to GO!) and stomp the gas... that thing would GIDDY UP!

just a thought.... lets hear some opinions.

i think i will pay 15000 for everything including parts and labor. but the kit must come with warranty.

i think i will pay 15000 for everything including parts and labor. but the kit must come with warranty.

same here. money ready :)

Anyone interested in this kind of swap...please pm me.
I dont have resources for unlimited 20B blocks, so if the customer can provide a block, then the swap can be done no problem.
I'm talking with a couple forum members right now about getting their 8's into the shop soon.

Make the 3rd rotor peripheral intake and exhaust
________
TopJoy. live (http://camslivesexy.com/cam/TopJoy.)

^Why? That won't work in conjunction with the other 2.

The rotor deactivation sounds cool but complicated. Didn't RX8PR say that he gets like, 18 mpg if he can keep his foot off the gas? Anyway, if you've paid $15k for an engine, I doubt that worse gas mileage would matter.

Besides, you've increased displacement by 50%...but does it necessarily follow that mpg is going to fall by a similar amount? You aren't adding significant weight, or any wind resistance, or rolling resistance. And if it's a problem, you could switch to the 4.10 gear and still have a car that's much faster than stock, while keeping RPM's lower than stock.

Well within a 3 rotor you are increasing friction by adding more displacement and a heavier eccentric shaft. Also it should be less thermally efficient, which is already not a strong point of the rotary engine. Those alone I think will adversely decrease gas mileage. I didn't see RX8PR's comment on mileage, I'd be curious to see what MPG he is getting.

edit: just read the displacement on demand idea...I'm by no means an engineer, but this sounds overly complex. I'd just like to see a properly functioning 3 rotor Renesis before I'd put more faith into the added complexity of DOD. To me, a rotary by virtue of so few parts is about keeping it simple.

it would be more complex for US, but not for the consumer (you). it would also keep cost down ALOT.

20B's do have a major problem with heat, but GTORX7 uses a pretty large radiator and does fine, even when hes on the track. the Displacement on Demand (i like that name by the way :)) would really cut down on the heat issue during normal driving. your car more often overheats in stop and go traffic because of no air flow right?

the other issue with doing a strait 3 rotor renesis, is im not sure on which stock intake features we would be able to keep, and which ones we will not, but we arent at that stage yet by any means.

wither way, the longblocks will be the same, so this could be sorted out later when its time to do the manifolds.

I can't take the credit for the "Displacement on Demand" namesake. I think it was first a GM term used for their Cadillac engines back in the 80s.

you want an intresting and powrful NA rotay with good gas milage?

take a 4 port engine and make it a side port an peripheral port engine, under normal driving conditions it works as a renesis, under hard driving it works as a peripheral race engine with a 10,000 rpm red line :rock:

saying you would buy one and committing financially are two different things entirely

Would the thing still rev to 9k? Seems to me that a 33%+ increase in rotating mass would lower max rpm.

Would the thing still rev to 9k? Seems to me that a 33%+ increase in rotating mass would lower max rpm.
honestly, i think thats the first question i dont know the answer to completely. i know GTORX7 can rev his N/A 20B to 10.5k, but his is rebuilt that way. or is on its way to be at least.

i would think it wouldnt affect it much at all, since all the rotors will still be spinning at the same rate. the shaft might see some extra flex though since its longer therefore easier to twist... but someone else can chime in on this one.

driveslikeajehu...is this just "idea's" or is actual work being done as we speak?

Just wondering how far along you are, my guess is this is mainly idea's right now (other than the stuff you already said you guys have made)

Hi all, I was offline for long due to my pc's hard disk failure,then getting new vpc and then software glitches.

I will love a 3 rotor but agree thats too much, especially to get it to us in SA,but why not take a normal 20B, put in high compression rotors, do a good bridgeport or street port with say Microtech LTX 12 engine management and do same idea as that other 3 rotor turbo from earlier.

should be good horses I think, and cheaper and more basic.

but no turbo, with a very light flywheel, and good exhaust / intake system,

a screamer.

to be honest this is what I am thinking of doing, later when the renesis says no more and no 3 rotor renesis is available at a good price.

U want a 3 rotor Renesis, simply duplicate the center plate from the a regular 20b and engineer some more stock 20b e-shafts. You would need the wider 20b's center plate for several reasons. For 1 the wider plate would allow for the engineering of the 6th ports and the correct exhaust area ratio. You can't have this if you used another center primary port plate. It's too thin and won't allow for the correct matching port area. Now as far as the tension bolts, either engineer some really longs ones with butt loads of dowel pinning or fabricate another front plate to accept tension bolts from the front like the 20b does. There's your new 20b Renesis short block. ;)

U want a 3 rotor Renesis, simply duplicate the center plate from the a regular 20b and engineer some more stock 20b e-shafts. You would need the wider 20b's center plate for several reasons. For 1 the wider plate would allow for the engineering of the 6th ports and the correct exhaust area ratio. You can't have this if you used another center primary port plate. It's too thin and won't allow for the correct matching port area. Now as far as the tension bolts, either engineer some really longs ones with butt loads of dowel pinning or fabricate another front plate to accept tension bolts from the front like the 20b does. There's your new 20b Renesis short block. ;)I think if you did that you would have issues making sure the same amount of air was getting into each of the rotors. Honestly you are going to have to make custom center plates to make sure the center rotor is running the same way the outer 2 rotors are. I like the idea of the 4 port per rotor mentioned earlier. It looks like a very good design. If you produce a 4 port per rotor, 3 rotor renesis, id be interested. that looks and sounds like a fantastic idea!

I think if you did that you would have issues making sure the same amount of air was getting into each of the rotors.


I know what your talking about. The stock 20B LIM is unbalanced because of the width of the center plate however, it is still capable of allowing the engine to make a tremendous amount of power reliably. If your going to bring up air flow issues, you might as well talk about how the center rotor always runs leaner in a 20b. The extra heat it gets from both sides of the engine naturally makes the center rotor run leaner. In the end, either of these flow imbalances can be tuned out. I mean we're talking a NA set-up here so it's really not that big a deal. A 9 port 20b is going to make the best power and be more emissions friendly in this application. 2 ports per rotor needs too much port area to match up with the flow of the aux ports. In a rotary more port area with 2 ports per housing usually means more over lap and lower velocity in the lower rpm's therefore killing any bottom end torque and less clean emissions.

Honestly you are going to have to make custom center plates to make sure the center rotor is running the same way the outer 2 rotors are.

Curious do you really understand how a 20b is put together? You would only be duplicating the stock center plate to allow for machining of the side exhaust and aux port. Racing beat currently has special aluminum side plates for the older 13b's to substitute the older heavier cast iron plates. Re-engineering the old 20b plate for side exhaust wouldn't be that big of a issue. Lastly the plate don't dictate the phasing of the rotors to make sure they run the same way, the e-shaft does. 13b is 180 degrees, 20b is 120 degrees and the 4 rotor in the 787b was phased at 90 degrees. Peace!

Any updates?

Thanks for the education lesson folks, while I'll probably forget most of it...lol

It wouldn't be too hard to get all the plates to flow equally. You just need to flow test them on a bench. The ports that have the least amount of flow need to be chacekd to see if any more can be freed up. If you can get them equal in flow to the rest, fantastic. You're done. If not you'll need to (gasp) decrease the flow potential of the other ports to match. This is actually a good thing though. Not too hard to overcome.

I personally think Racing Beat should modify the castings of their aluminum housings to include a side exhaust port but retain the 13B 4 port intake configuration. That would rock!

U want a 3 rotor Renesis, simply duplicate the center plate from the a regular 20b and engineer some more stock 20b e-shafts. You would need the wider 20b's center plate for several reasons. For 1 the wider plate would allow for the engineering of the 6th ports and the correct exhaust area ratio. You can't have this if you used another center primary port plate. It's too thin and won't allow for the correct matching port area. Now as far as the tension bolts, either engineer some really longs ones with butt loads of dowel pinning or fabricate another front plate to accept tension bolts from the front like the 20b does. There's your new 20b Renesis short block. ;)
mazda recently discontinued the 20B centre bearing plate, and they arent doing another production run. theres a guy on the rx7 forums that got the last one in austrailia.

I like the idea of the 4 port per rotor mentioned earlier. It looks like a very good design. If you produce a 4 port per rotor, 3 rotor renesis, id be interested. that looks and sounds like a fantastic idea!
the center plate thats already in the renesis isnt wide wnough to put 4 ports on it. making that plate wider means a whole new e-shaft, which means two more things you need to replace to get a 3 rotor, and two more things that dont exist.

from hear say (not my personal experience) aluminum plates wear down REALLY fast because of the rubber seals on the rotors spinning against them. thats why the plates are cast iron and the housings are steel "plated" ... sort of.

I will love a 3 rotor but agree thats too much, especially to get it to us in SA,but why not take a normal 20B, put in high compression rotors, do a good bridgeport or street port with say Microtech LTX 12 engine management and do same idea as that other 3 rotor turbo from earlier.
this involves either a complete japanese 20B, or all new 13B parts. both we are trying to avoid. we wanna use all renesis stuff, because we know its going to be around. the last 13B was made 11 years ago in the US, its only a matter of time before mazda discontinues those parts. plus you can use existing parts from your renesis, rather than getting an ENTIRE new engine.

we also want this car to be daily driven... and a bridge port basically throws that out the window. once we have a "stock" renesis 20B that works and get some numbers from that, THEN we will tear it down and REALLY see what it can do.

driveslikeajehu...is this just "idea's" or is actual work being done as we speak?

Just wondering how far along you are, my guess is this is mainly idea's right now (other than the stuff you already said you guys have made)
yes its being worked on currently. yesterday we found a 1990 FC N/A 13B that we are tearing down. you ask why? because the intake ports on that are very similar to those of the renesis... imagine that. we can use this for measurements, as well as the renesis center plate (for exhaust ports) and 20B centre bearing plate (for width) we are trying to obtain. once we finish measuring and CADing, we can mock up an aluminum plate to be molded, so they can be casted, then machined. once everything is measured and designed, its pie from there.

sorry for the delay on the update. oh yeah, the "displacement on demand" idea has pretty much been killed by some things we forgot about.
- it will basically be miss firing when its not in use since they are phased at 120 degrees rather than 90. we dont know what this will result in, but thats enough to scrap the idea. we arent trying to re-invent the wheel.
- the oil thats put into the housing for the apex seals wont be burned.
- avoiding compression when not in use.
- some others i cant remember off hand

mazda recently discontinued the 20B centre bearing plate, and they arent doing another production run. theres a guy on the rx7 forums that got the last one in austrailia.



I know that. I'm talking using the stock 20b center plate as a basis to fabricate a new one for the Renesis like Racing beat did with their aluminum side plates. Using that plate would allow you to reuse a stock 20b e-shaft.

from hear say (not my personal experience) aluminum plates wear down REALLY fast because of the rubber seals on the rotors spinning against them. thats why the plates are cast iron and the housings are steel "plated" ... sort of.

That all depends on what's used on the side plate surface. The stock iron side plates have a nitrided coating on the chrome surface to reduce the wear. A newly engineered aluminum side plate can be engineered the same way. Look at the aluminum rotor housings, those housings have a chrome ring on the compression surface.

I know that. I'm talking using the stock 20b center plate as a basis to fabricate a new one for the Renesis like Racing beat did with their aluminum side plates. Using that plate would allow you to reuse a stock 20b e-shaft.



That all depends on what's used on the side plate surface. The stock iron side plates have a nitrided coating on the chrome surface to reduce the wear. A newly engineered aluminum side plate can be engineered the same way. Look at the aluminum rotor housings, those housings have a chrome ring on the compression surface.

oh ok, i wasnt clear on what you were saying. we are defiantely using a stock 20B plate for a basis for the renesis plate, so we can use the stock 20B e-shaft like you said.

as for using aluminum and other metals. coating and layering im sure could be used for this application, but i think that casting and machining is the most accurate and cost effective for us right now. its also what we know how to do without a doubt. once this thing runs im sure we will look into other metals like you said.

Cool anyone with some photo shop skills wanna modifiy this drawing showing how this new center plate may look with Renesis side exhaust and aux ports? Here is a pic of a new 20b center plate to get someone started.

http://www.rx7club.com/attachment.php?attachmentid=154000

drivelikjehu...thanks for the update, I'm glad this is past the "initial idea" stage and actual work already started.

Per fellow rx8club members, they have said that the 4port (from the automatic RX8) Renesis would make a 3-rotor Renesis alot simpler. Have you thought about exploring this idea also? I know we all would want the 6port since it could develop more power but if the 4port could give us 300whp and still rev to 9K...while being cheaper and simpler...then maybe this is an idea worth exploring.

Again…thanks for the effort to build a 3-rotor Renesis!

if the intake ports on the renesis are the same diameter as on the engine we have in the shop (they are very close, but maybe not exact) then 4 ports wont fit on the existing center plate, which means it would also have to be widened.

this creates two problems.

1) there wont be an existing e-shaft that will have the correct spacing between the lobes for the rotors and their housings.

2) an entire new center plate, as well as the intermediate will have to be designed and made, not including the new e-shaft. thats 3 entirely new parts that will have to be designed and made. so the price is going to be even more outrageous.

if the ports are SMALLER on the renesis then on this 6 port engine we have, then it might actually work. but i dont think this is the case. if someone has the end plate of a renesis so they can measure the diameter of the intake port inlets, it would be very useful.

making the inlets small enough to fit with the width of the existing center plate would restrict it more than keeping the slotted design.

The ports on a 6 port Renesis are much larger than those of the 6 port 13B. Most of this diference is on the intake opening side. The intake runners are also very different. They are farther out on the Renesis which means that the air doesn't have to turn as sharp to enter the engine. The secondary intake runners are slightly larger on the Renesis and the auxiliary port runners are much larger as the auxiliary port valve actuation system is not done the same as the older engines. The 6 port 13B probably isn't the best model to be using. You really need to have a Renesis housing.

oh were not using this engine for measureements by any means, really just looking at the plates for casting purposes, since they are the closest to the renesis plate, and free.

It's been 4 days...is the 3-rotor Renesis built yet?

LOL :p:

Honestly because of the cost involved for a 3-rotor and the poor bang for your buck NA mod's for the RX8, my love of NA power is getting more and more strained...I hope one day something comes along...

Hey Rotarygod, where did you get this info that the Renesis intakes are much bigger than the 13B.. The reason I 'am asking is, if this is true than maybe that explains why the boost falls on the FI systems. On my thread on New intakes, maybe its not the intake on the Renesis that's making the boost fall , but maybe the Turbo isn't big enough when the all the auxilaries kick in..

If that's the case , I wonder if twin seq. turbos would be a good idea for the Renesis...By the way I would love to put in a 3 Rotor Renesis in my 8, But try to keep the pricing reasonably...

All you have to do to find out that the intake area is larger is to look at one and compare it to a 13B. I've plyed with a few of them and compared them to the 13B. They are definitely larger. The port runners in the primary ports are the same size but the ports themselves open earlier which gives you more port area. The secondary and auxiliary runners are larger and again the ports open earlier which is more port area.

When it comes to boost falling off, it is all about turbo size. It's definitely not the intake's fault. The turbos used are just too small on the compressor side to make the needed power up high. This is the most likely explanation. There is one other possibility though.

The exhaust ports on the Renesis are terrible. I've seen them and played with them. When it comes to flow they are laughable yet the engine makes alot more power than the naturally aspirated 13B. There may be considerable pumping losses in these stock exhaust ports. Basically they could be a big restriction. Think of the difference in power between using a cat and not having one at all on a turbo car. It's huge. Now just build that restriction into your exhaust ports. A restriction gets worse and worse the faster the air has to travel through it. We might just be reaching an area of diminishing returns. It wouldn't be too hard to improve the flow of these ports but that requires opening the engine up and having some fun with a die grinder. We've got nice large intake ports but small poorly flowing exhaust ports. When it comes to making more power from forced induction, you need good exhaust flow. All you'll do with an exhaust restriction is to crank up the boost for little gain but more importantly you'll really increase your engine temperatures and the stresses on it. This is a possible explanation and at some point this is true. Where that point is I don't know. Since a few people have already crossed the 350 hp mark, I would start with the turbo size first. Porting definitely won't hurt it though.

^ i completely agree with this.

although with the exhuast ports being on the side of the housing, you can port them just like you can the intakes. imagine if it were possible to do a full bridge port on the exhaust like you can on an intake. the tradition 13B has peripheral designed exhuast, so flow is increased, but at the same time effciency is decreased from unburned gases crossing over into the intake chamber. this is where the side exhuast port design shines.

once we build this engine in the 'stock' form and get some base numbers, then we will tear it down and rebuild a monster. porting everything pretty well (keeping it daily driveable), and stream-lining the intake and exhaust manifolds to let everything breath. get some numbers from that. then tear down and rebuild again using FC s5 rotors and scalloping those, then slapping a huge turbo on there and seeing what happens. this one is a looong time down the road though.

my guess is the port job and opening up the intake and exhaust on the N/A 3 rotor renesis will crush 350. but once you hit 400-450+, your looking at a whole different ball game. at that point, the entire driveline needs to be upgrading to keep from ripping your car apart or staying on the road.

the cool thing about having an N/A motor... is that you can still get a WHOLE lot more out if it if you want to spend the time and money. you can only go so far with FI. unless you dont care about rebuilding every six months or your car is for the track or weekends only, then go ahead and pump that boost up!

i would either (a) get a c6 corvette or (b) wait for the new toyota supra or (c) wait and see if the kabura comes back as the rx-7 in explosive form. but, i'm really leaning towards the supra if push came to shove...

i would either (a) get a c6 corvette or (b) wait for the new toyota supra or (c) wait and see if the kabura comes back as the rx-7 in explosive form. but, i'm really leaning towards the supra if push came to shove...
what about the new 2008 skyline GTR? first one ever to be sold in the US. that takes my vote.

and you could buy a new rx8, and (once we build this) do a 3 rotor conversion, and probably slap a huge turbo on there for less than a new c6, and you would CRUSH it. and youd have a completely unique car. i see about 5 c6's a day, and that number keeps getting larger.

....but to each his own.

p.s. that kabura thing is UUUUUGLY!

Thanks for the info Rotarygod/guys.
Question, you did'nt answer if a twin seq. turbo like the 13b would be a route to go and if the exhaust seems to be more likely the case in the Greddy scenario, then would a new exhaust manifold be also beneficial or not.. So it looks like you saved me $ 1,599.00 thanks.

Also with regard to Detrich, Hey I was ---this close to ordering a C6, but after see one everywhere I realize how much more I really like my RX8 with all the changes I made, it just
looks much more unique then what I've seen out there so far...

The exhaust ports on the Renesis are terrible..

Do you feel that porting the exhaust ports would net anything in N/A form?

If the exhaust ports are the biggest restrction for this motor to gain more power, perhaps Mazda should look into redesigning the ports for the next gen RX-8.
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I will do it. Iam talking with speed force right now to boost my 8 to 400whp for 12-15k. If you can get me a motor that has at least 100% 300whp all motor and later look into a turbo system iam very interested. If this is for real i would like to get into touch with you over the phone. And see what we could arrange.

Nice movement since I last posted...and yes, RG...if it's that bad then wouldn't that be a huge area to work on for NA power in our Renesis?

drivelikeajehu...not to distract you from the 3-rotor project, but has your company thought about maybe working on the 2-rotor Renesis and just getting as much whp you can out of it without hurting reliability or adding a Turbo?

I feel that the exhaust ports need the most attention in the engine. The intake ports can be cleaned up a little bit but I really wouldn't enlarge them at all. The exhaust port area is far less than the exhaust runner area. On top of this the transition from port to runner is horrible. The first thing that needs to be done is to address this issue. You can enlarge the exhaust ports a little bit and this would help to smooth out the transition into the exhaust runner. The ports wouldn't get alot larger but flow would increase. From there I would work on the exhaust runner on a flowbench and actually add material to the runners. I see no reason why you couldn't make the runners smaller and still have them flow just as much. That's the goal. You want as much flow through as little area as possible. Larger is not always better. If this can be accomplished then you could design a good header that had the same sized primaries in it. Now you can better take advantage of the velocity in the exhaust to help pull the charge out of the other rotor.

The stock exhaust ports are so bad right now that even though the stock exhaust manifold has a terrible shape to it, it is still better than the ports. Even replacing the cat, muffler, header, etc isn't going to do much if you aren't addressing the single biggest isue in the system. No one has yet. Once you fix that issue you'll see other mods do a bit more. Don't expect miracles though. The engine is quite easily capable of flowing enough air for 250 hp. The problem is the cost and effort of making it happen. You cn pretty much figure that if you increase the flow internally that the ecu will overcompensate for it and you won't get much out of it. It's always something. Naturally aspirated power is expensive.

I will do it. Iam talking with speed force right now to boost my 8 to 400whp for 12-15k. If you can get me a motor that has at least 100% 300whp all motor and later look into a turbo system iam very interested. If this is for real i would like to get into touch with you over the phone. And see what we could arrange.
You won't get 300 hp naturally aspirated.

The stock exhaust ports are so bad right now that even though the stock exhaust manifold has a terrible shape to it, it is still better than the ports.
What you mean by this? You mean that the renesis exhaust ports are better than the older 13Bs exhaust port?

The Renesis exhaust manifold is just worse than the exhaust ports themselves. That's why we aren't seeing much in the way of gains from exhausts. The exhaust is fairly good compared to the actual ports in the engine.

RG, IMO you're still hung up on typical exhaust theories that aren't going to apply to this engine until you port overlap into the timing cycle. Given that, the OE design is actually not that bad or critical even. That's why you aren't seeing the usual header gains. Yet to prove it myself, but slowly working on it.

Once you see a Renesis exhaust port, you'll know what I mean.

The exhaust ports on the Renesis are terrible. I've seen them and played with them. When it comes to flow they are laughable yet the engine makes alot more power than the naturally aspirated 13B. There may be considerable pumping losses in these stock exhaust ports. Basically they could be a big restriction.


Another way to test the exhaust port area differences is if we had an old 13b with the same greddy turbo with Renesis 10.0 compression rotors and compare the spool differences. This would give us a better indication when comparing the flow differences between the two engines exhaust ports since both engines displacement is exactly the same. Now I know manifold design would play a big part but the PP exhaust manifold could be engineered similar to the greddy piece.

You won't get 300 hp naturally aspirated.
on a two rotor no way (unless your fuckin awesome) but on a 3 rotor, easy.

well, the guys fron new zeland sell parts to built your own 3 rotor engine and 4 rotor engines using 13b parts, I think it can be posible but it will be harder than an old 13b and more expensive.

13B and Renesis rotors and side plates are not compatible. Cause of a oil ring thingy i think ..hehe..

my race engine its a street port 13b with renesis rotors :rock:

yep renesis rotors are fine with 13b parts and vice versa. side plates arent compatible mainly becuase of the side exhaust, but im sure theres other reasons. i dunno has anyone ever tried that?

rotary crazy: what are the specs on your engine? did you notice anything with the rx8 rotors being scalloped?

I dit not built the engine, some one in florida dit (he is a weird guy I will ask him firts if I can say his name here) there is some machining of the rotor to take 13b side seals thats all, and power its totally diferent than it use to be with series 5 NA rotors, they are sclloped difrently( going on memory) but cant tell you exatly how diferent they are, maybe RG can give you a better idea.

Im trying to get him to built me a NA 20b street port with renesis rotors for street use but he is really busy this season :mdrmed:

It's easy to use Renesis rotors in a 13B. You just leave out the cutoff seal. That's it. They drop right in. You can't machine them to use the 13B side seals. The grooves are already larger than in the Renesis. The nice thing is that you can buy oversized side seals for the Renesis that will allow you to get to clearances smaller than they come in the RX-8.

I dit not built the engine, some one in florida dit (he is a weird guy I will ask him firts if I can say his name here) there is some machining of the rotor to take 13b side seals thats all, and power its totally diferent than it use to be with series 5 NA rotors, they are sclloped difrently( going on memory) but cant tell you exatly how diferent they are, maybe RG can give you a better idea.

Im trying to get him to built me a NA 20b street port with renesis rotors for street use but he is really busy this season :mdrmed:
you must have some serious cash flow. especially if you arent doing the work yourself. damn it must be nice...

Here's a photoshop rendition of what jehu had sketched out in the other thread.

http://img56.imageshack.us/img56/3260/3rotorrenesis0gb.jpg (http://imageshack.us)

well you have to remember the intermediate plate is much thicker because it holds a stationary gear and bearing, or else it wouldnt be doing anything to spin the shaft. with it being alot thicker, the ports will be spaced out more and fit much better.

on a two rotor no way (unless your fuckin awesome) but on a 3 rotor, easy.

http://www.mazdatrix.com/r-20.htm

Not for street use tho...
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http://www.mazdatrix.com/r-20.htm

Not for street use tho...
It can be, I've seen people use them on the street and daily drive. Tuning is key, exhaust setup is also key, it can be done...

It can be, I've seen people use them on the street and daily drive. Tuning is key, exhaust setup is also key, it can be done...
thats a RACE engine, a whooooole different ball game. when you say youve seen people drive them on the street do you mean from here to there, or to and from work everyday as a daily driver?

everything on that engine is completely custom or different in some way. you wont be able to find a replacement part from anywhere but there. and a p-ported engine typically doesnt see the streets everyday...

but theres always exceptions to the rule.

thats a RACE engine, a whooooole different ball game. when you say youve seen people drive them on the street do you mean from here to there, or to and from work everyday as a daily driver?

everything on that engine is completely custom or different in some way. you wont be able to find a replacement part from anywhere but there. and a p-ported engine typically doesnt see the streets everyday...

but theres always exceptions to the rule.
To and from work. It was this crazy dude from around my area, it was a Pineapple Racing p-port with carb tuned by Rob over at Pineapple and lots of other goodies. Also ran nitrous with it on the street.

Of course there are exceptions, always are, I was just pointing out that some people ARE crazy enough to do it :)

To and from work. It was this crazy dude from around my area, it was a Pineapple Racing p-port with carb tuned by Rob over at Pineapple and lots of other goodies. Also ran nitrous with it on the street.

Of course there are exceptions, always are, I was just pointing out that some people ARE crazy enough to do it :)
that is defiantely crazy! just curious, what was the gas mileage on that thing?! i drive 45min to work everyday, thats a hell of a lot of gas even for my stock FD.

that is defiantely crazy! just curious, what was the gas mileage on that thing?! i drive 45min to work everyday, thats a hell of a lot of gas even for my stock FD.
No clue, never asked him. If you're driving a pport on the street, I don't think you're too concerned about gas mileage :p:

I just saw pictures (finally) of what you all mean when you say porting, street port, etc etc. The Pport is pretty radical I must say so that guy is pretty nuts about his rotary, lol.

A question, why is helping the car breath better increase fuel consumption? I would think that would help things out...not just for power???

It's easy to use Renesis rotors in a 13B. You just leave out the cutoff seal. That's it. They drop right in. You can't machine them to use the 13B side seals. The grooves are already larger than in the Renesis. The nice thing is that you can buy oversized side seals for the Renesis that will allow you to get to clearances smaller than they come in the RX-8.

so all I need to put renesis rotors in a 13b are new side seals? wich side seals?

you must have some serious cash flow. especially if you arent doing the work yourself. damn it must be nice...

Lets just say I really love this hobbie :mdrmed:

and people like me are the ones that are going to buy your kit if you get it finish :)

so all I need to put renesis rotors in a 13b are new side seals? wich side seals?
You could just theoretically swap them into a 13B with all the stock seals and have it work. I would buy new side seals from Mazda. They make a set which are longer so you can clearance them yourself. I would not use these in a Renesis though as the extra clearance is necessary to prevent seal breakage from carbon buildup. The 13B's don't have this problem to this extent.

I would also mill out the apex seal grooves deeper and then use 13B apex and corner seals. The Renesis corner seals have a new special coating on them which makes them very hard. These seals will chew up a 13B side plate in no time. The Renesis side plates have a different coating which is stronger so they don't get chewed up. The 13B corner seals can not be used with Renesis apex seals but they are the one's you'll need to avoid scrapping your engine in short time. Some have reported the Renesis apex seals to flex when crossing the 13B exhaust ports but others have reported them to work fine. My biggest concern is the corner seal wear.

By the time you mill out the rotors for the 13B seals, you will have spent the same amount of money as you would have if you had just bought the S5 RX-7 high compression rotors which require no special attention. Of course they aren't as light. The Renesis rotors have not been able to top the power of the RX-7 rotors in a 13B yet. The compression ratio difference is 9.7:1 vs 10.0:1. This isn't enough to matter in a rotary.

Thanks for your help RG.

your completly right I call mi mecanic and he said the same thing as you , but he said that in his experience the renesis rotors give 20 more hp and 10 lbf of torque with some tuning, and this is what I saw at the engine dyno when my engine was put together, but not every one has the same luck with things.

so all I need to put renesis rotors in a 13b are new side seals? wich side seals?
...Some have reported the Renesis apex seals to flex when crossing the 13B exhaust ports but others have reported them to work fine....
ive heard this same exact thing. the peripheral exhaust suposidly chews up the seals. but as you did, i heard people both for and against that claim.

By the time you mill out the rotors for the 13B seals, you will have spent the same amount of money as you would have if you had just bought the S5 RX-7 high compression rotors which require no special attention. Of course they aren't as light. The Renesis rotors have not been able to top the power of the RX-7 rotors in a 13B yet. The compression ratio difference is 9.7:1 vs 10.0:1. This isn't enough to matter in a rotary.
agreed also. although the renesis rotors are scalloped a little, you can buy already machined lightened and scalloped (much much more than that renesis also) S5 rotors. supposidly the heavily scalloped rotors on a street port make it sound like a full bridge port with no bridge! theres huge advantages to the scalloping theory, but it seems not TOO many people go that route. cool stuff though.

A question, why is helping the car breath better increase fuel consumption? I would think that would help things out...not just for power???
when you add air, you need to add fuel to keep everything happy.

someone else can explain this better... but im way too tired right now :sleep:

^I forget, I've heard the same before...no need for more information...thanks.

But...the people who get the REVi intake consistantly have said they got slightly better fuel economy... :Wconfused

Maybe, it's just that it helps the air flow better into the engine...

Remember if you change the efficiency of the engine, it may take a different amount of air and fuel to make the same power. You only need a certain amount of air in relation to fuel to get a certain a/f ratio. This does not hold true to power though which is why you can get a mileage increase.

Ah ha....thanks

On a high overlap engine such as a peripheral port you need to run really rich at idle just to keep it going. Actually you need to ruch them farily rich almost everywhere. You gets tons of exhaust gas dilution at lower rpm's and loads which is devoid of oxygen and very hot. This hurts efficiency. You need to run lots of fuel just to get enough to combust well enough to keep them running. That's true with any engine really as that's how they run but in the case of a large overlap engine, they are very inefficent at low load and rpm levels. Higher rpm's and loads are different. This is where the inertia of the gasses tends to stay more in the proper direction and the overlap can even help build power. At full throttle a peripheral port will make more power almost everywhere in the powerband than an engine with less porting. This isn't terribly usable on the street though. If you drive around in the engine's rpm/load efficiency zones, you aren't going to get good mileage because you are flooring it everywhere. If you drive around like a regular street car, you aren't going to get good mileage because you'l be out of it's efficiency zone. It is physically possible to drive a peripheral port on the street. By some people's standards this means it is a streetable car. Of course we all know that a Formula 1 car can physicaly drive down the street and so can a Cessna airplane but I wouldn't consider them streetable because of it. Port overlap adds eficency at higher throttle settings but suffers at lower. That's the tradeoff. Mileage follows efficency at that load level. Most street driving is at fairly low loads which is an advantage to less overlap when it comes to efficiency.

my perfect engine would be an engine that uses side ports for normal driving and when you go to wot and over an rpm point it opens peripheral intakes and exhaust ports so you get the drivability and economy of a renesis with the power of a PP.

^^^
The rotary version of V-tech...

alot of things would have to change in an instant for that to work without a huge delay from the time you stomp the pedal until you actually feel the car move. entire ports along the entire engine would have to shut and open in perfect timing, fueling and firing would have to change instantly, and the ecu would have to compensate for this huge change.

that would be so cool. it would have to be a FLAWLESS design though. possible if you have the time and money... but thats something better left to mazda IMO.

^^^
The rotary version of V-tech...
You're already got that!

Indeed, the 4 and 6 port engines are like 2 and 3 stage vtec, in that each set of ports effectively changes the intake opening and closing and total area ('lift').

This is what you guys are looking for.

D'oh, my mistake RG. I've even read your write-up before about the variable intake being our version of V-tech...

Ohhhh...we now have pic's, thanks RG...lol

Me learn good wit pics...

that picture is great! just remember the distance between the 1st and 2nd rotors is not proportional to the distance between the 2nd and 3rd rotors.

it is the same in the 3 rotors kit they sell in new sealand, remenber it uses only 13b parts

BUMP!!!!

Long time no type....anything on this.....ANYTHING...lol.

Like the Handheld Flash Tuner thread.... Patience what else?

^yeah, but lately there is NOTHING to report on anything it seems. The site has been rather dead lately...

I disagree, its been rather alive in the MAJOR HP SECTION With the SUPraAaaaaaa EIght, maybe the supra guy convinced all of us rotor heads that 2JZ owns 3 rotors... maybe drivelikejehu should make a skyline 8 instead of 3-rotor renesis =d

hahahahaha

edit: i meant the aftermarket section
________
SensualJessica (http://www.girlcamfriend.com/cam/SensualJessica/)

no, he should do a 3-rotor-renesis powered Supra, ha ha

lol

A question, why is helping the car breath better increase fuel consumption? I would think that would help things out...not just for power???

more air = more fuel needed to get the correct A/F ratio.. The quicker you burn fuel, the more energy you have and therefore more HP and Torque..

Any news or is this just another dead dream?