It looks like I may have to build an exhaust for my bros '84 GSL-SE and I was just wondering what size to make the pipes. I'm not real sure how much back pressure this thing needs. I run 3in pipe on my GSX but I think that may be a little too much for the RX. I'm probably going to go with the racing beat header, magnaflo or catco universal hi flow cat and magnaflo muffler but I'm not sure what size pipe to run.

I appreciate the help,
Adam

 

i dont think backpressure matters, its the exhaust velocity. but when you make it smaller for more velocity it does create more back pressure .

dont quote me on this but i think racing beat uses either 2" or 2.5" and they are top of the line as far as rx7 exhaust systems

 

NA= 2-2.5"
Forced induction= 3"

 

I've heard 2.25 is optimal for a stock-port engine. But 2.5 is easier to find, and will perhaps give you a bit more once you've ported it.

 

If you use a racing beat header be careful of the lower ground clearance. I put on on my car and now the header section hangs too low (grinds on speed bumps) . I will try to beef up the engine mount on the passenger side maybe that will help. Anyone else had this problem?

 

im going full 3 inch when i go turbo


-greg

 

You shouldn't have droped the car

 

2.5 is too large for na. 2.25 is best , 2 inch would be better than 2.5 on a na. 2.5 is the most you would need on a stock turbo. with an upgrade on the turbo 3inch would be best. on na with headers go for dual back like the racing beat one