Recently I purchased my beautiful 04 GT. Since then, I did everything I do to all my cars: intake, coilovers, wheels, ngk plugs and wires, new coilpacks, and now I'm looking for exhaust. I'd prefer headerback exhaust to unlock a little more power, but this where I'm undecided.

I've done a lot of research and learned that these cats can ultimately be killed and clogged by misfires and bad ignition, along with high temps. Once the cat is clogged, the motor can go with it. My car (and cat) only have 11k miles. I'm assuming these OEM cats don't typically go bad to higher mileage, correct? So considering my mileage, would it be worth it to sacrifice the cat for a midpipe too?

If I get headerback exhaust, I would prefer a catted midpipe. I was going to go with the turboxs setup, but it seems to have a bit of raspiness to it. So, for what it's worth, I may just get a catback.

What do you guys think? I've read the gains from the midpipe are minimal, which is surprising because I figured the OEM cat would be the most restrictive part of the car, with intense filtering for rotary emissions. So should I just get a catback, or spend the extra couple hundred now and swap out the cat too while I'm at it?

 

I'd just get a catback. The main performance bottleneck are actually the exhaust ports anyway and even with a good header, de-cat mid-pipe and exhaust you're only seeing something like 4-8bhp total gains, possibly a little more if you also have someone competent remap the car. If you're not changing the header, putting in a catless mid-pipe isn't going to do that much for you.

That said, if you are planning to track the car it might be a good idea to have a race pipe in your arsenal just for track use. Rotary exhaust gases are very hot and running on the track can shorten the lifespan of the cat.

If you do decide to remove the cat, keep in mind that it's going to affect the noise levels as the cat also muffles the noise. You might want to consider a midpipe with a resonator in it.

 

I would go mid pipe with a resonator as stated above and work your way back. Keep the CAT around for inspections if your state requires such. Or if you just get sick of smelling unfiltered rotary exhaust. Keeping your ignition parts changed every 20 to 30 thousand miles will help eliminate killing the CAT should you decide to keep it on. I removed mine just to eliminate that potential point of failure. There is not much to be gained by changing the header on the RENE.

 

Black Halo Racing Midpipe - Has a resonator, increases noise and flow. Mine is Catted because I have dumb emissions laws and rules in my state (But not for long, as I'm moving to an area where it doesn't matter.) I also have an HKS Hi-Power and it. is. LOUD. Single exit tubes, while reducing weight are very loud. Like "Let me coast on idle for the next mile in this subdivision otherwise someone's gonna call PD on me." Go for a twin-pipe system, HKS Legamax is great from what I understand. Big mufflers are good. These cars get loud, quickly... But at 8k RPM in the mountains it's pretty fun.

 

If you want the best sound, get an R Magic exhaust. The tips are titanium so they change color while driving. Personally I think that's the best sounding exhaust for the RX8. Look it up on YouTube

 

Upgrading the exhaust system to gain more power is a futile attempt really. You won't gain any noticeable power and you'll have a car that with the wrong exhaust, can be a loud and annoying raspy machine that will certainly gain the attention of the law.

Now, if you are more concerned about a better sound or exhaust tone and want a quality product, I would buy a Racing Beat exhaust. Best product I have found in the last 18 years of owning the RX series, 35 RX-7's and 4 RX-8's. The have a mellow tone that won't get you into trouble and the piping is thick enough to withstand the heat of the exhaust temps. Many cheaper makes will have the muffler packing blow apart or melt down, disintegrate, etc. You get what you pay for with the RB exhaust.

 

BHR makes great catted midpipes and other exhaust setups. tested and proven.

 

Went with a TurboXS catback for now and it sounds awesome. I was tired of getting catbacks in the past and having a quiet note from them. The TurboXS catback alone is loud enough to turn heads. Is it loud on the inside? Yes, but that's what I was looking for. Is it overbearing? No, not quite. It also sounds amazing for a 1.3L. I plan on getting a high flow catted midpipe for the future and am looking the RacingBeat one.

 

Racing beat or BHR, can't go wrong with either!

 

I have a turbo xs cat and a racing beat cat back. The last car was all turbo xs and was ear bleeding loud. It hurt. The cat back was destroyed in the accident. I bought the racing beat one for the next car.

These two line up, but I had to switch to slightly narrower bolts to make it happen. They were a few degrees off.

XS with the factory cat may be fine, but with a high flow, it was harsh. I installed an auger silencer, but it was still loud. Good news was, no matter what someone did to a honda, I could not hear it.

 

Get BHR LongTube Header + any cat back
I have thorougly enjoyed my ExoticSPeed RII Titan Exhaust it was not only the best looking exhaust but sounded amazing and shot amazing flames..

Also note, when you take off the CAT and OEM catback off you shed some weight off plus unleash the tiny bit extra power lol..

 

Yeah,

The OEM Cat was a lot heavier than the high flow cat. The new exhaust was heavier than the old one. weight off the front, weight to the back. Not bad...