Greddyturbo1

Hey guys I have not seen any threads comparing the Rx8 Motor build up versus the 93-95 RX7 build up, if I'am wrong please someone correct me ..

I'am really in a confused state on which way to go. First off for those who know me know I have an RX8 with 284whp Greddy Turbo setup in my car, and I know I should be happy with that since most don't seem to be putting out that much with the Greddy...

But spring is around the corner and I'am looking for some major changes for this car, so here goes.......

Does anyone really think this Renesis motor can handle the same power and more than the 93-95 Rx7....This is very important so please any and all experts in this field let me know, Because if this Renesis engine won't handle what the 13B can , then I won't go through the trouble of installing a bigger and better Turbo for the RX8... Maybe I would either go with a 13B built by one of you experts, or maybe a 20B... So again please I'am asking all you experts in these rotaries to chime in, also I'am not looking for an all out race only car here, But one that can handle the power and still be streetable and not blow-up so easily... Thanks, Rich

rotarygod

I'm really tired right now so I'll give a detailed comparison later. I will say that the Renesis can be pushed up to around 400 hp or so which is plenty. Keep in mind that if you went with any other rotary in an RX-8, you will lose the ability to pass inspection and this is ignoring the fact that your emissions would go through the roof by comparison.

Fanman

There are a few kits out there running 330 whp now with better reliability than the Greddy. As long as you get all the supporting mods I think this engine can run reliably at that power level. Not sure if you are looking for more than that, or how much more.

gh0st

while there are kits that put out a little more HP, they are doing it with the aid of a larger turbo, more consistent management and pretty extensive fuel upgrades. in that sence, yes, they are theoretically more reliable but your comparing a kit that is maxed out at 290whp vs kits that can push 360+ running at 330 with standalone management and fuel upgrades.

there is no question that kits like the mazsport and ptp are made with more quality but i suspect that if you take a greddy kit, change out the rubber pieces, modify it to take a larger turbo, pop on the same emu and fuel upgrades and ran it just as conservatively you'd get similar results. you'd also be spending just as much though (ie. arm, leg, ********, 1st born).

IMO, not all the issues with turboing a renesis have been addressed. when the first greddy kits were blowing up we thought "conquer the ECU, power and reliability will come" but ive heard of at least 2 people that have blown their motors with the int-x. fanman being one of them. both owners were not pushing their motors. also being at 10:1 compression, we have to tread lightly in a time when turbo cars run 20+ boost from the factory and when many turbos dont reach max efficiency until they hit the stratusphere.

i dont think there have been enough of the more roboust kits in circulation to conclude they are more reliable. they should be and my fingers are crossed but only time will tell.

to address the topic, if a kit as beefed up as the mazsport units where installed on an FD, it would easily outproduce an 8. for now.

gh0st

20b.... DO IT!!

it will offer the most hp and torque without sacraficing streetability. DO IT!!

RX8THELAW

the renesis engine can't handle big boost or power of north of 3 and change the engine is just not meant and was not constructed for that purpose if you want more power the best way to go is with a fusion of a renesis & a 13b or 13b all together or 20B to get better power & if your looking for 20B then acostamotorsports i think is the most capable shop to do the 20B swap

rotarygod

It's easy to say that a few Renesis motors have blown up regardless of the ecu's running them and then claim that the engine isn't strong as a result. Explain then why so many RX-7 people blow up their engines? I've seen people with forced induction on a 13B blow them up at 250 hp before and I've seen Ari make 620 rwhp on a stock remanufactured block. The Renesis is really no different in this regards. It's not a weaker engine than the 13B and all evidence actually says otherwise when you really get down to the little stuff. It's got plenty of performance capability in it. Of course you will always have the people who will throw out the card that if the engine had more in it we'd have seen it by now. this attitude really cracks me up! The engine is plenty strong and plenty capable in the right hands.

zoom44

acosta the most what?

chickenwafer

iTrader: (9)

I believe the Renesis will eventually outproduce the 13b in terms of power once more tuners get on board and work out better FI and EMS options. Once the Renesis is unquirked, I think there is plenty power to be had.
I remember when people first starting tooling around with the 3rd gen RX-7 and it's twin turbo 13b-rew, people thought max output was something like 380-400-rwhp before it became a one-time use fun gernade. But then better tuners got involved and better products came out, and now a 550+ rwhp FD isn't that crazy, and 700 seems to the be "streetable" ceiling- nearly double what was orignally thought.
Now I'm not saying the Renesis is capiable of 800-rwhp or even 500-rwhp with any means of reliabilitly, but the Renesis, although sharing much of the same deisgn as the 13b, is still different and has different tuning needs. Don't worry, the power will come with time.


Dave

SlideWayz

I think the biggest thing that's holding back the Renesis is a lack of low compression rotors. Once the compression ratio comes down it can be force fed more air.

I don't know what anyone will do with all that power, though, because even with the GReddy and a good EMS I can't keep mine hooked up even with bigger, stickier tires in first thru third gear when the torque comes on. Yeah, I could go 19s & staggered, but then the handling won't be balanced.

Do you really think this is the right platform for making use of crazy WHP ?

mikeschaefer

So what exactly would be left of the greddy kit? A few pipes and an intercooler

RoXanneBlack8

fyi the renesis IS a 13b

Renesis_8

IMO the biggest thing is lack of market demand and R&D $$$$$
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BATISTA

Greddyturbo1

I appreciate all this input, so thanks...
Let me explain alittle bit more,
1. Looking for around 425-450whp
2. Rotarygod, I'am not worried about passing emissions, because for that one time every two years I would put the original Renesis motor back in, That's of chorse if I was to use the 13B from the RX7.....I would do something else if I had the 20B installed..
3. Cost comparison which engine would be cheaper and more reliable to accomplish
my goal..
4. Also very important, This year, This Spring, I won't wait another year...
Please all comments will be appreciated... Rich

dillsrotary

20b seems to be the answer, cuz if you go 13b with a single turbo you'll ask yourself why didn't i just go 20b to begin with.

be prepared for some major transmission work though, in addition to everything else along with a swap.

N rider89

if you want power from a known powerful source just swap in the 13b from the fd.

the rx-8 has potential but there just hasnt been enough development done yet to see its full potential.

if you are as confident as you sound with an engine swap then by all means just go that way and swap back when it comes to emmisions.

Skiptomylue

i think the people getting the crazy power, dont really care about the track/handling, i think they want it more for street/drag racing,
err.. correct me if im wrong... but.. i dont think you'll be able to swap the 13b in very easly at all?

Renesis_8

If you're just looking for 425-450whp, thats not too far away from the mazsport kits, maybe before you decide between the 13B-REW and the 20B, give mazsport a call to see if Scott can make you a one off kit that can push that much power

it seems that money isnt a big concern for you, cause you are considering the 20B, which is great. That opens up a lot of possibilites!
________
real estate for sale Pattaya

dillsrotary

correct, some custom work, and no chance of swapping a renesis back in probably (correct me if i'm wrong but the frame or cross member has to be cut)

WantedTwo

iTrader: (4)

I have a feeling that RG is hard at work in MS Word right now. And I cant wait!

rotarygod

Actually I've written on this extensively before. I need to go find that thread again.

EDIT: Here it is:

https://www.rx8club.com/series-i-tech-garage-22/advanced-renesis-tech-99617/

Greddyturbo1

hey Rotarygod, like always thanks again for your knowledge on this subject. I did read all you suggested . I did read that you said the exhaust pulses are different from the Renesis versus the 13b, you also said that the pulses are more like a piston engine, Do you feel in any way that this difference might make the Renesis less likely to boost like the 13b.

With the info I read about the Renesis, It does seem to be a better engine, But I didnot see any info on -

Whats the cost comparison to building the Renesis versus the 13B 93-95RX7 engine to handle the kind of power I'am talking about..

Renesis8, I should call scott to see what he's upto...Friday.

I believe it would much cheaper to swap a 13B-rew in the RX8, There is so much more parts available and I bet cheaper.
And just like N Rider89 has said there just is'nt enough development yet. But I will call scott see where he is on these turbo kits..

gh0st

i hope you didnt take my post the wrong way, i firmly believe the renesis will prove to be a more durable motor. my comment with the ECU is to show how there simply isnt enough info to give a clear and definitive answer to the original post. i agree that we still cant explain all rx7 failures and we probably will but for now we have a lot more experience older rotaries and we are just starting to explore the renesis (obviously).

youve pretty much answered your own question. 450whp has yet to be reached on a renesis so a comparison isnt possible yet.

as for the exhaust pulses go, most turbos are designed with pistons in mind so the more we can mimic the signature the better. id like to see just how close our signatures look though.

Greddyturbo1

ghOst, thanks for info, you say that 450whp has not been reached yet so there is no comparison yet, but there is... Mazsport is saying 400whp for $ 8,500 so we can compare 400whp cost for both engines , does anyone know what it would cost to put out the same numbers for a 13B... Now we are just talking parts to achieve this, not swapping motors,mods etc.

Moon Assad

Looking at the way new parts for 7s keep rissing id think it would be a good idea to stick with the renissis. The parts are alot cheaper for the 8.