Just out of interest i\'m wondering what is the most powerful (non turbo and non supercharged) rx8 out there after it\'s had a few mods done. Has anyone ever achieved 280bhp+ and if so what mods have been carried out. I still have a few things I want to do to mine then gonna get it rolling roaded and see how it performs.
From the US forums, the best NA seems to be 220 to the wheels and that takes a lot of money from the racing teams. Otherwise, intake/exhaust/mapping gets you to 200rwhp.
One UK guy I was email with about my mx5/renesis conversion claimed 269 engine bhp from the Renesis but this was for an offroad vehicle, everything custom, no cat.
The impression I get is that the RX8 engine is pretty well tuned from the factory and unless you go forced induction (or nitrous), the possible gains are very limited.
There was the pip did not too long ago that was a 3 rotor PP, ran around 450bhp. Although that isn\'t the stock engine !
The 13b in the Rx8 is very well tuned to start with !
Shaun
If that was the one in Banzai, I expect that was based on the 13B from the RX7 rather than the RX8 13B.
so if i was to remove cat on mine this wouldn\'t count as its strictly not road legal?
Quote from: mj2326;720797so if i was to remove cat on mine this wouldn\'t count as its strictly not road legal?
Not legal is my understanding.
Have a look at http://www.rx8club.com/ for improvements to non-FI cars. (US site)
think i\'ll do it anyway i think we pay too much tax for emissions and the fact that their not making the 8 anymore is a sad thing
Quote from: jpc;720787If that was the one in Banzai, I expect that was based on the 13B from the RX7 rather than the RX8 13B.
Yes based on the rx7 13b, but there has been a renesis 20b built before and and used in an rx7. Carl built the engine if I remember rightly !
Shaun
our kit car with an rx8 engine made 251 fly on the stock original engine on reworx dyno which reads lower than most. Just a decent set of headers and Motec Ecu
Does anyone have the sports cat fitted and would reccommend this instead of the decat pipe for an increase in bhp
I\'ve got a high flow cat on mine, I don\'t think it makes significant power difference however the reduced silencing and increased flow make it sound gnarly.
where abouts did you get your high flow cat from ive seen petit racing do one 420 plus vat
I got mine from the States but Pettit\'s one is the same.
Quote from: shaunwil;720786There was the pip did not too long ago that was a 3 rotor PP, ran around 450bhp. Although that isn\'t the stock engine !
The 13b in the Rx8 is very well tuned to start with !
Shaun
268@9.2krpm :) :WaveBye
I can\'t see it getting much higher than that without serious internal work.
In fact, the SII engine we\'re now running has a bit less peak power, just over 260, (but holds onto it for longer, so we\'re not too bothered, it\'s only done 1300 miles so it\'s probably a bit tight anyway)
Nice ! Is that at the wheels or the Flywheel ?
Shaun
Flywheel, I wish that was at the wheels! :lol:
Rather less at the wheels by the time it goes through a van transaxle and high-angle CV\'s with big knobbly tyres unfortunately!
We don\'t have any cat, 105db exhaust, plenty of room for nice long runners on the manifold, heatshields, straight through fuel rails, bit of tidying on the ports/manifold, etc, etc. Nothing that gives a lot of power (if someone finds something that does, let me know :D ) but lots of small gains here and there.
Supercharger soon though so it might be ;)
I think mazda pulled as much out as they could safely without too much headroom !
Sounds like a great deal of fun :D
Shaun
It is indeed, bit of video of it on the old engine here:
http://www.youtube.com/watch?v=kj6jiFTUHxg
\'s a bit faster now, new engine, lower ratio diff, wider wheels + better tyres, higher limiter, new airbox, dropped a couple of 2" baffles out of the exhaust (only way to get it meet the sound regs in time last year).
Like you say though, there\'s not much in these engines that Mazda didn\'t already get, not without serious reshaping, and tbh, there\'s not much room for that either without going peripheral.