im new to rx7 and i was gunna buy two n1 mufflesr for my 88 rx7 n/a..i was gunna have 2 1/4 pipe from the cat back then y pipe to the two n1 muffler..would this be and alrite set up? or is it a bad idea..aslo how would it sound..i really dont no much about exhaust and have searched but couldnt really find the answer i was lookin for..thanks

 

Seeing as how you have an 88 your auxilary ports are being opened by your air pump I believe (someone correct me if im wrong), But this is your only real concern with changing exhaust, as up until 87 the aux ports were being opened by backpressure from the third cat. So you shouldnt have to worry about that.

You might want to remove your cats as RX's have very high temperature and high flow exhaust, and unless the cats have been changed/gutted yours are most probably clogged. Removing them will allow much more flow and increase performance.

Hope that helped
Cheers
zip

 

so u think if i run 2 1/4 piping from the header back with a striaght pipe to dual exhaust it would help it out alot?

 

S5's are 89 and up. 88 is an S4, meaning it uses backpressure to activates the aux. ports.

 

https://www.rx7club.com/showthread.php?t=655093

 

I have an 87 N/A and I replaced the factory exhaust with a race header into 3'' Exhaust, ran that into a Cherry Bomb then Y off into my Ractive duel mufflers. I assure you it is loud. It sounds great, not like a ricer Honda. These engines are very loud by nature anyways, and if you dont mind the sound,it can help open your car up alot. Most benifits are noticed at high revs, some minor compromise at low end which there isnt much of anyways. P.S Most will say a Cherry Bomb is a bad idea for a presilencer, because of the heat. But once you blow the guts out of it (3 days of spirited driving) it has a helps add a nice deep sound to the larger exhaust.

 

well i dont have money for headers rite now so i was gunna have the local muffler shop run me piping..just not sure what size of piping i wanna have him use..i was gunna run a straight pipe to a ypipe to two n1 mufflers..do i need to have a silencer or anything or is that just pretty much personal preferance?

 

If you take out the cat's your auxiliary ports will not open on thier own. You'll need a special header from racing beat if you want to run a test pipe and have them open. If you run dual N1's it will be very loud, especially with no cats.

Right now i'm with gutted cats into a single N1 style muffler with my secondary sleeves removed and it's loud as hell. Most guys on Harleys look over to check out the other Harley coming thier way and are surprised to see it's me. Not to mention you can hear it idle about half a block away.

If I had my druthers I'd have the cats back in and some racing beat mufflers. Nice tone and not too obnoxious.

P.s. You can always wire the ports open.