what are some ideas for better performance on a 1985 rx7 1.1L 12A (Automatic transmission). if i change the exhaust, i think i might want to change the cats also, but do i really need all 3 cats or just 1 or 2? do i need to change the manifold while im at it or just leave it alone? some people told me that if i were to change the exhaust, that i would have to put the same piping width in it and the same muffler also, because they said if i made the piping bigger and added another type of muffler that i would lose horsepower instead of gaining it. is this true or not? Please i need some ideas

 

I think, if I remember right, the local guys say to go with a 2" exhaust, no bigger.

You'll need a muffler designed for the rotary to get any kind of gains.
Are you in an emissions state? If so, you'll want to keep your exhaust damn near stock. If not, hell, don't put any cats at all!

You're losing most of your power through your tranny, to be honest.

 

i'll tell you what, go to this website: www.mazdatrix.com you'll find a few performance parts for your car. or try this: www.racingbeat.com as far as exhaust goes, get the racing beat exhaust. as far as the auto trans, swap it out for a 5 speed. also, try the search feature. it'll help a ton and save lots of time. welcome to the club.

 

do i really need all three cats or can i just go with 1 or 2, i live in VA.