I did a search but couldn't find the answer I was looking for.

I'm wondering if I cut my cats off my 85 GSL-SE if it will hurt performance or make it better. Where I live I don't have emissions so not worried about it. Plus this is mostly autocross car anyways.

I'm wanting to put a 2.5" from the header to a magnaflow muffler out.

Discuss...

 

u will increase performance and your noise level. be careful of the exhaust pieces u put on an rx-7. the exhaust is 3 times as hot as conventional. I have melted glass packs and turbo pulse mufflers. check mazdatrix.com for compatable replacements for performance based issues.

 

HighwayRacer speaks the truth

Cats restrict the exhaust gas ALOT and thus decrease your HP. The only thing you have to worry about is that with a GSL-SE, you have 6th ports which are actuated by exhaust back-pressure. RB's exhaust system is built to deal with that (as long as you get the GSL-SE specific one).

Conventional exhaust WILL deteriorate faster on a rotary due to the extreme heat and pulsing cycles. Check out www.racingbeat.com . They're a little more expensive, but definitely worth it. Get the GSL-SE specific exhaust package. You only need the headers and presilencer to be able to do the back-pressure activated 6th ports, but the muffler is awesome. If you want/like loud, you can go with another muffler.

Jon

 

I personnally recommend getting the muffler too.. I had a normal stock one ( not the ordiginial, but still a stock ) and it's now shot , I'm gessing because of the bigger backpressur ... BUT, I did notice a gain in power so ... up to you ! ... ohh yeah, I'm getting my muffler within 2-3 weeks from RB, thus completing my complete RB exhaust .. NA NA NA NA NA NA !! :P

jkjk

 

i heard that rotaries run like 2200 degrees and normal conventional cars are around 1600-1800 degrees to the headers and exhaust. is this true?

 

but hell i wouldn't know. my cats are clogged and i live in CA so emissions is all up my @$$. haha. damn pollution *****. once i pass smog somehow, then my rex will breathe! without cats. muhahahahaha!!!!!

 

Get a Racing Beat presilencer to replace cat. Heavy duty for rotary engin & runs free. Don't know about CA emissions but RB is in CA so just call. RB is the industry standard for performance & fuction.

 

that is nearly true. the exhaust temp can get up there but usually stays between 16-1900 degrees. so i am told. lets put it this way, i wouldnt want to have my have on any of the exhaust even 15 mins after the car was shut off.

 

thanks guys, I think I'm just going to go with the Racebeat exhaust. Its damn expensive! It better be worth it...

 

just buy the racing beat headers, and get a shop to weld all the way back to a RB Muffler, RB whole system package is good but it will damn better sounding this way and cheaper

 

How do you get a shop to weld your exhasut and not put a cat back on?

 

If you don't have a cat to begin with then it's no problem, ie. custom, if you're taking one out and replacing it with a straight pipe thats when they're going to bitch.

 

yeah the only prob about the RB presilencer is the money. I am too poor to afford that at the moment. CA emissions are a bitch, and I cannot drive without a catalytic converter on my car. I am lucky b/c I live here, not lucky b/c of emissions. Luckily I am getting a free cat from my friend's shop and having a straight pipe hopefully made, not installed though. The same shop who is giving me the cat will install the straight pipe for me. it's going to be a straight pipe/ cat bolt on conversion. it's going to be sweet. then to top it off, because of the CA emissions *****, if i have my straight pipe in, I will have a catalytic converter cover covering the pipe so it looks like my cats are on. TRICKY TRICKY!