Can Rx8's produce big power like the Rx7?please view
 

Ok guys,(my apologies if this is a re-post!) I need confirmation on this but there is a big argument on the irish rotary forum that i'm a member of that Rx8's can produce big power.I disagreed that they could but thats just from sources in the rotary world.We all know what fd's can do with the right money and tuning and the reason i'm posting this up in the 3rd gen specifics is coz there is a few comparisons between the 7's and 8's (just so the moderators know!).There are quite a few 8's over here and I don't know if there are many over there but if anyone can post up some information about it that would be awesome.Here's the link of the argument so you get the jist.Note of warning,there is a lot of crap posted up!!!!:lol:
http://www.irishrotary.com/forum/php...?p=22807#22807

We're not here to help you win an internet argument. Do a little research yourself before spouting off on internet forums, who really cares anyway? You don't get a prize for being right. Go check out www.rx8club.com and read for yourself.

Through design, the renesis cant make power like the REW.

It wasnt designed to be power efficient IMO, it was designed to be more fuel efficient IIRC which they still failed at doing.

How much money do you have?

Sure it can... just fill the ports in on the irons and go peripheral port intake and exhaust. ;)

Wow man:scratch:,someone needs to get laid!!!!Personally I couldn't care less about it.I have had an fd for 5 years now and know nothin bout 8's so was just lookin for a bit of info bout them,NOT TO WIN AN ARGUMENT.I've gotten a lot of useful info on this forum whenever I have asked for it so a little more never hurt.Thanks for your input though:icon_tup:

My thoughts exactly!

I knew the renesis model was the big hp model but wasn't sure of its capabilities.I read about the turbo'd rx8 in tokyo drift and they didn't even make 300 at the wheels on the dyno.Yeah you're right,they still guzzle the oil and petrol like the fd

I think some guys in PR managed 500hp but those guys are insane. I remember watching a BM video with a 500hp rx8 but it had a REW in it hahahaha. I think because of some side ports or something, boosting a renesis to really high power levels is not easy to do. Im guessing that is what the argument comes down to right? 13b-rew vs. renesis?

This is something you could look up easily. Its been asked many times.

Yes, but the FE only makes 5hp less than the FD stock

Im confused, whats the paint your trying to make?

Spot on!I've never seen it done which is why I was wondering?

The main reason is different exhaust ports. Potentially, the renesis can make just as much power, BUT you have to be VERY careful.

You have to remember, the higher the boost you are running at, the harder it is to spin up that turbine, and the more back-pressure you will have because of that.

Under high boost, back pressure builds up in front of the turbine. It sometimes reaches critical levels where the side ports on the renesis get warped, and you need a new engine.

This is not such an issue on the REW, because of the apex seal being beafier and wider than the side seals,
also, the exhaust is pushed out in a straight line in the REW rather than at an angle as it is in the Renesis.
Finally, the single exhaust port is simply BIGGER which allows for stronger pulses that can have more force to push through the turbo. Also, the bigger exhaust port allows more room for the exhaust gases to be compressed and not do damage.

I would imagine, however, that with a straight-pipe and a correctly set-up cooling system, you could push just as much power of the renesis.

Tell me what you think about my theory

It sounds like you know a bit about 8's my friend!
If it can be done in the renesis engine why is it so rare to see a tuned,modified or single turbo 8 on the roads:scratch:?I haven't seen or heard of one here or in the uk.I've actually seen more bugatti veyrons!!!:hahaha:

so then i have the perfect solution to that problem...supercharger! haha im planning on putting either the pettit or the new hymee rx8 supercharger kit in my rx8 this summer..guys are making 350whp with a bone stock motor at only 8psi. so im sure there is much room for improvement..

True .... but you will run into the next weak link - the plastic intake manifold that likes to explode under high boost ... i was in the market for an 8 for a while .... until i decided to go fd. Honestly, if I did get an 8, I would try to keep in N.A for a while ... then I would go with the greddy and then the greddy turbo delete kits ... straight pipe, custom intake manifold and would get 350-400 at wheels ... i dunno about reliability though

I wish I could get my hands on race-spec renesis 3 rotors though!

try getting a horizontal intercooler in your 8 ... few have done it ... it would be so legit!

Its starting to sound like just sticking a 13b-rew would be easier.
I really would like to get an LSx inside an 8 real bad. That would make a fun dd.

^um no

RX = rotary

piston = gtfo

It basically comes down to it that you can't take an 8,port it,up the injectors and stick,lets say for instance a t78 in it (or a big turbo kit thats compatible for the 8!) and expect big hp figures.I just said those mods coz they're the basic big mods on an fd,feel free to correct me!!!
I would consider getting an 8 if the other half told me she was foaling and we needed the back seats for a baby seat,otherwise i'm staying fd for now!!!!

the supercharger kits come with a new cast alluminum intake manifold so the old plastic intake gets thrown away..

I dunno how good supercharges are for an already low torque motor tho ... on a rotary, I would still go for turbo. I think Mazda is moving in the right direction with keeping it NA with direct injection.

http://www.mazda.com/mazdaspirit/rotary/16x/

Contact Alec Bell in New Zealand +64-9-577 1047 sales@kiwi-re.com if you want a race spec renesis 3 rotor engine.
The current NZ dollar currency exchange against the US makes for a real bargain. The Puerto Rico Major League RX-8 car runs one. This is also the only car in the world to have run under 7 seconds with a Customer Crate Rotary engine Package.

well you should go over to rx8 club and do some reading..people are just bolting on the supercharger and reflashing the ecu and they are making 330 whp at only 7psi

If for you lots of power = 400-520whp then yes it can ....:)

I should know....

http://videos.streetfire.net/video/E...RX8_210037.htm

This video was on pump gas at about 16psi with the stock esmeril racing kit as it comes out of the box. The same car/engine was later switched to E85 with astonishing results running 20psi on a PT71gtq turbo. Now a new intake manifold and intercooler setup is being fabricated...

Best regards,

Chris

I know .... I am just prejudiced against superchargers ... and N.A engines will always have a soft spot in my heart. But you should check out some more paperwork on how mazda is changing the geometry of the engine to get more torque rather than just linearly increasing displacement

Is that backfire at 2:35 in that vid?

And how can an Rx-8 tranny handle all that power? I thought they were weaksauce

Link to the Renesis Motor

http://www.rotaryengineillustrated.c...-pictures.html

And a link to all Mazda Rotary Motors

http://www.turborx7.com/repics.htm

Here is a excellent link for animation and explanation of more Rotary engines. Download the Renesis animation and all engines are explained

http://www.turborx7.com/rx8renesis.html

Lol .... point proven .... I may have to be in the market for an 8 now instead of a 7

Please show me a link of where this is happening on the rx8 club. I believe they are not making 330whp at 7psi, its more like 13psi+ I am just saying that I wouldnt give the supercharger that much credit on the rx8...its not just gonna give the torque that people are looking for. As for the turbo, I believe its the way to go. But then there is always the debate turbo vs. supercharger....

the JIC magic D1 RX8, rod millen's Grenade RX8, and tony angelo's RX8 all have the REWs in them. arent the mounts in the same place?

Very few people have achieved 400+whp with an Rx8, but it is possible if you have enough money to invest. Alot of owners that go FI first purchase the Greddy kit and then upgrade the turbo and other components.

turbocharging the rx8 (oem block) is a waste of time.That thing runs high compression, its not like the fd block ...and..no you cant change the gasket to lower it neither put low compression pistons lol

So what has brought you to the conclusion that turbocharging the rx8 is a waste of time. It can't produce crazy numbers like the rx7, but I believe there is a guy on the forums both (7 and 8) that his renesis can produce over 500whp. So then its just becomes a personal preference as to how much power you want and what you are going to use the car for. With Jeff (MazdaManiac) tuning with the Accessport, it has really opened the door for having 300whp+ with reliability.

i say give it two or three more years when people like me can get their hands on one and spare engines are available from cars being totalled. every time an engine changes format people hate it. hell people hated the ls1 at first... look where it is now.

i still believe.

Read my post, Turbocharging the rx8 with OEM block is a waste of time. you will end up hurting the motor fairly quick and it wont produce the full potential.. if you wanna turbocharge an rx8 do it from scratch, new block, new intake manifold and something important that hasnt been mentioned here is the gearbox.. it will not handle much power


Youre answering the topic's question

I understand what you are saying, but to say it is a waste of time IMO is a little bit exaggerated. If I have done the research correctly...

The clutch is good to about 320-325 h.p.
The input shaft on the trans will generally snap around 400 rwhp.
The PPF snaps at 420.
The rear axles snap around 420-450.
The rear control arm links bend at 600 rwhp and the rear differential is close behind it.

This is coming from a very good source on the rx8 forum.

I think ChrisRX8PR with his 500whp in still using the stock transmission if I am not mistaken, I maybe wrong. I think he just upgraded his clutch. But other than that its holding up. Correct me if I am wrong Chris.

So with the transmission being a weak point, even at 375whp that is still good power to be decent for a car. Hell even with my crappy TD06 Greddy turbo I was able to break the speed limit pretty damn easy. And it was probably around 275whp. I can't wait to turn my boost up, run meth, and tune with my new upgraded 60-1 turbo from BNR on my rx8. It will only be a matter of time before you are able to consistently see BIG HP from the Renesis motor.

Uhh...no its not.

All we do at Esmeril Racing is turbocharge the RX-8. We've sold over 25 turbo kits (Our own kit, not greddy) and most of them are at 350whp and a few have passed 400whp. Its all about tuning. More compression simply means it takes less boost to make the same power...you just need to know how to tune properly. Even so, if you are worried about reliability, we offer the only available Apex seal upgrade for the renesis out there and they have handled 500whp+ on our test car, albeit on E-85.

Here is our web (Please excuse the fact that its primitive, we are working on a flash site as we speak): www.esmerilracing.com

I believe 400whp can be attained comfortably and on pump fuel. for anything above that, good fuel is required.

Oh and the tranny is good for up to about 550-600whp from a 20b(proven) if not abused and probably 600-650whp from a 13b/renesis because it will have less torque so that is not an issue....

Best regards,

Chris

Thanks Chris for clarifying and for your support...

There is one fundamental thing that makes the REW easier to achieve more power out of than a Renesis and that is it's lower compression ratio. As was stated above, higher compression means less boost per the same amount of power. The problem with this is that is doesn't mention detonation qualities of the fuel used. In a perfect world we'd have the highest compression ratios that we could use while still having good ignition timing and hitting our power goals on the fuel chosen. The problem is when someone wants one of these variables to increase without touching the others. Let's say that at a 10:1 compression ratio you can run about 18 degrees of total timing on 92 octane at 13 lbs of boost. I'm just making this up. Let's say that this is all you can do and that any more timing, or boost will result in detonation. What do we do? That's the problem. People complain rather than realizing that their setup isn't optimized for more. The solution is to run a higher octane fuel such as alcohol or at least some other type of anti detonation measure such as water injection.

What if we don't want to do this but still want more power? What's the solution? We can't raise the boost without backing off ignition timing. We may in fact pick up a little power this way but we also may be at a point where we'd have had more power from a lower compression engine at this point because it could run more timing. Everything is a balancing act and when you are near the edge of optimal, it can be a very difficult thing to do well. The best solution would have been to lower the compression ratio by using lower compression rotors. Unfortunately that's not an option on the Renesis. The REW already has lower compression rotors than a Renesis so it can take more boost on the same fuel and still run a decent amount of ignition timing hence greater power for any particular fuel used. If the Renesis came with 9.0:1 compression, we'd be seeing 400+ hp regularly on pump gas. There are only a few people who have been skilled enough to do it though with the current compression ratio. Even still, with an REW engine, you don't see many people top 450 rwhp on pump gas. Yes a few have but most don't. It's still a brick wall, it's just higher than the higher compression ratio Renesis. The truly high powered REW engines are not using pump gas. As Chris pointed out, he's hit 500 hp on a Renesis but it was on E85 which is a fuel that has the detonation characteristics that can handle this on that engine.

People need to understand that the Renesis is a fantastic engine. It's not a lack of port overlap that holds it back. It's mostly the high compression. People are just scared of it for some reason. It is true that there are other areas that it isn't the best in when it comes to FI but then again how many n/a 2nd gen engines have we seen boosted really high?

Nailed it, Fred. Every bit of this making power thing rests upon the quality of the fuel once the engine (and turbocharger) part is decided upon. The fact is pump fuels aren't made for the high power potential the RE engine is capable of making. When going from a low to high compression setup, this fact about pump fuel's deficiency is further exacerbated due to a rise in chamber heat.

+1.

B

I dont mean to offend you but READ MY POST.

I am saying if you wanna do the right job and go for high and reliable numbers, you need to rebuild the block. Yes you can achieve 350-400hp max on the oem block...but Lets stick to the original question. Can the rx8s produce big power like the rx7? by just a turbo kit, NO THEY CANT.

I have turbocharged an rx8, using the greddy kit and it produced 310hp on 0.4 bar with greddy's preloaded map on the e-manage. YES it can go more but not like the fd

Is this 310hp at the crank? If its whp really, that is the first time I have ever seen that. Do you happen to have a dyno sheet? If this is the truth, then good on you. But I can dont see how at only 0.4 bar you are making that much power on the stock greddy turbo. Even at 10psi most people dont get up to 295whp+ because the turbo doesnt allow you to flow that much. Its to small on the rotary. Not trying to cause a feud, just would like to how you were able to produce 310hp on the stock greddy kit the way it was shipped from the company.

310 crank hp not WHP... The kit i bought came with the emanage and a specific map for this setup

rx8 motor was not engineered for boost with reliability .
if you want reliable boost you need to go with a 13Brew

would anybody like to humor the thought (and comment) of sending FI to only the auxiliary ports as a way to possibly bypass some bs on the renesis? I probably should have started a new thread but oh well.

uhh ... WAT?

I mean ... you might as well make a frankenstein engine ... which I believe some people have done .... like 13b housings + renesis rotors .... i am not fammiliar with the pros and cons however, but we are getting off-topic