All this talk about exhaust, what about a cutout?
 

http://www.quicktimeperformance.com/QTEC/

I'd like to get a CZ Stage 2 with no cat and a resonator and hook this up where the cat was... And thoughts? I was thinking the only problem I predict is the O2 having a problem with a little fresh air. Or loosing power from not having much back pressure? Not really an expert on the subject.

Picking up my Ti 6 speed in the middle on next week.

Nick

Interesting device. From what I know about the RX8 I do not think this will help. The RX8 needs some backpressure to generate max power. It will also be very LOUD and probably shoot flames from under your car.

You could do a whole custom exhaust for that much money. Not worth it.

That's kinda the point, quiet (stock) exhaust when you want it and as loud and annoying as can be rotary roar on demand. For 185 bucks I'm willing to give it a shot and sell it if it causes a loss of power. Now that I think about it the best place would be right before it splits into two at the rear end of the car. Hopefully it will provide enough back pressure to make some extra ponies. And you don't have to open it completely, I it takes around 2-3 seconds for it to fully open/close so say hold the switch for 1 second and you would have some good back pressure. I just don't like a loud car (or possibly ricey) all the time.

I thought the least back pressure would be best for power...? Why would back pressure give power??

I'm sure someone else can explains this more technically than me...

It has to do with exhaust pulses and gas flow.

I did a dyno session with my Mini Cooper and the lowest numbers were when we ran it without anything pasted the cat.

Same thing with performance 2 stroke engines - a tuned exhaust makes much more power and a better rev band than just an opened system.

Hey! I thought of this before! I didn't know someone was making that kind of device :D That's cool! But I'm not sure if it would benefit the RX-8 though.

I have one of those for my turbo 1st gen RX-7. It works great on a turbo car as no exhaust is the best exhaust. On a naturally aspirated car however you are only looking at a few more horsepower depending on where you install it. The noise is incredible with a rotary engine though. It starts to resemble the ricers who like their cars really loud but they don't have the performance to back it up. It is a fun device and a neat thing to have on something like an LS1 Camaro or Corvette that does get a noticable gain but the rotary doesn't benefit very much from it. I don't personally recommend it unless you plan on running a turbo in the future.

I think it's kinda cool. But FYI, these devices have been around for years sold out of the J.C. Whitney catalog. Their model is cable actuated rather than electrically with a solenoid, and a whole heck of a lot cheaper at $40!

Dunno, I might consider one, but definitely NOT without running some kind of a pipe out from the cutout. The uncapped rotary engine throws flames out the exhaust big time, and you could seriously fry things under the car if you don't direct the flames somewhere. Not good to cook your brake lines and such, you know?

Another thing about running a rotary unmuffled - it's actually loud enough to literally blow the windshields out of cars you pass. Yeah yeah I know, that'd be cool (:D), but not very practical on the streets.

Cast iron baby!! Wooo Hoooo!!!!

Flames from under the car?!?!?! Oh yeahhhh, baby! Robin, to the Batmobile!

I fired mine up with just the pipe on it (no mufflers)... it was loud, but not nearly as loud as I was expecting. The cat does a fair bit to muffle it, I think.

Wait until you actually drive it and accelerate under full throttle with an open rotary exhaust. You'll be in for a shock.

Enough to torture the poor corner workers, that's for damn sure.

I myself would rather spend a few more dollars and not have to deal with welding cast iron to mild steel (That's what factory exhaust is made of I assume?). Terrible with an arc, even with a MIG I get a few cracks.

$40 bucks baby!! Wooo Hoooo!!!! :D