Okay, I have been very interested in the RX-8 for a while and finally got one, and not to my surprise, I am also disapointed in the hp and performance. So I have designed a non-sequential twin turbo system for the RX-8. My only real question is... how much can the Renisis handle? I am doing a full stand alone emu(which if anyone knows who I should take it to for the final tuning I am all ears) so really I just need to know if the actual components can handle approx 18 lbs of boost or more.

 

I'd be willing to bet you could make it at least a 1/4 mile before it blew.

j/k

 

No. You bought the car for the wrong purpose. You want a straight line car you should have bought a GTO or something. But I don't think many people have gone over 14 yet. But hey, maybe your turbo is special.

 

Can I do something as simple as changing out the rotors? Or should I just think more along the lines of swapping in a 20b and modding that?

 

way to give him dumbass replies, guys.

fast_rides88, There's a bunch of people doing 12-13 psi on the car, I'm not sure about higher. I'm sure others will chime in.

 

Depends, what are your goals? 400whp reliably is probably reachable now, but you'd probably want to do some internal mods (porting, seals..). With more development more could probably be had. For anything over 500whp, you should probably consider that 20B.

The limits of the Renesis aren't known because few have pushed beyond the current standard. So this question will only get you speculation. Although, the rx7 community can provide alot of insight.

 

I would be very happy with around 400 whp.... the reason for the twin turbo configuration is that I want to get the boost early, but I cannot describe how much I had superchargers... I will be doing some internal stuff but I didn't really want to get carried away (i.e. remachining etc...)

 

You will have to machine the rotors to fit different seals in them. Check out Scott from Mazsport. He is working on such things.

I have to agree with you. The one thing I love about the Greddy turbo is instant boost, but you're limited to around 300whp with it. I would love to see a twin turbo kit.

 

I have actually contacted HKS to see about getting their turbos for a discounted price for advertising (i.e. stickers on car or what not) and also brought up possibly selling the design to them for production. If not... I may just see about selling them custom order.

 

Why don't you be the leader and show us the real limits of the renesis with good tuning.

 

Well, for durability you have Racing Beat rotor machining (take off about .2 lbs), Racing Beat modified metering oil pump, Ianetti Ceramic Apex Seals, 550cc's+ fuel injectors to & try porting it a bit. If you live in Los Angeles, I'm sure this might be a project Guitar Junkie wouldn't turn down. PTP has pushed the car to about the high 300's, so around 400 whp seems plausible. But nobody has done a twin setup. Has always been T04/GT35r type turbos, but flow is flow, so 400 whp seems doable with the right supporting mods.

 

Good luck. There is no reason you can not get that kind of boost to work with the proper tuneing. I have seen the 13B work with 38lbs boost with a single T72 putting out 510 HP ,,, but it was not the Renesis 13B.
I think I would be doing some porting to up the intake/exhaust flow capabilities.
Let that baby breath.

 

I was told by someone with rotary history that at 20 psi the rotors on the Renesis give out and become "ventilated".

 

renesis should be stronger than a 13b rx7, since the seals are totally enclosed it's all side ports. also the rotor housing are much stronger and the seals are much stronger than stock 13b rx7 seals. the only real problem is the higher compression rotors. at high psi unless it is tuned very well you are going to get detonation or preignition.. it's going to limit the boost you can run until you can lower the compression. afaik there is noone making lower compression rotors yet.

 

Compression ratio isn't near the problem some think it is, with this engine or any other. In this particular application the weak spot seems to be that Mazda, in order to reduce rotor weight and achieve the 9K+ redline, removed material from the backside of the rotor face. This leads the rotor to be unable to contain the dynamic pressures when getting in the neighborhood of 20 psi boost. The reason that compression ratio isn't as problematic as it used to be in modern engines, particularly piston engines, is due to combustion chamber shape. Pretty soon piston engines won't have much of a combustion chamber at all and will follow in the footsteps of Diesel engines and, instead, combustion will occur in a dished piston rather than a domed c.c.

 

This line right here makes me think you don't know what you are doing.

"Approx 18psi...or More." That doesn't sound like anyone with a plan - sounds like a kid with a dream.

Build your system - Tune it to run as safely as you can, and leave it. If that's 10psi - fine....if it's 200psi, cool.

 

with 400horses you have to mod more than the engine Good luck dude!
Olddragger

 

If it is 400 at the fly, OD, things should be okay with street tires. Drag radials make things a little iffy, though. The input shaft on the trans, PPF, and rear axle shafts become issues around the 450 rear wheel mark either way. Then at 650+ one can look forward to bending the rear lower links. I am making some great connections with shops who can help me pursue stronger versions of all those parts. Remember, my first fabricator abandoned those projects. Back to our regularly scheduled program......

 

kid with a dream, you are silly. that does not happen here.

over and over again.

beers

 

are you here yet... i see a mazda 3 in my future for the commute!

beers

 

hey it doesnt matter. if he can put up the money and create the twin turbo for the ren. then its all good. and you all will love him as much as...say...rgonza. if he doesnt make it.... fine. we all have dreams. letg us think on them if he voices his maybe he will find others with the same idea and they can build it together.

 

Who will love whom? I don't love ANYONE for what they do to their car. That's crazytalk. I'm not a fanboi of ANYTHING but the Republican Party, Big *****, and Sci-Fi Friday.

 

safe boost I will say is 7.5psi and max. 300whp. Many ppl saids is get 300whp+, but the question, is how long will effort before blowing the rotors. My single turbo kit is only set up to wastegate (7psi).

 

what happened at the end of SG1? i missed like 15 minutes

 

I think you should talk to PTP & Speed Force Racing, they have had well over 300 whp RX8's running for tens of thousands of miles. Not about boost level, it's about airflow. A Greddy boosting 7.5 psi, is far different then a kit with a GT35r, or big T04 flowing 7.5 psi.