The 79 RX7 that i just bought has stock exhaust,but is being shipped with a car full of "goodies".Im getting a header and i think its a pacesetter.I have to weld it to the existing exhaust,but i am wonderring since i have to do that i should go ahead and do my exhaust.Question is what size to go with.My upgrades as of now are intake and Delleots card setup.I love the sound these rotarys make,just dont know if 3" is to big or would it be just right?

 

2.5" will be fine. 3" is overkill if the car is NA & has stock or stock-like ports.

 

2 1/4 if thats all you plan on doing and is it a 12a or 13b?

 

Im sorry its a 12a

 

2 1/4 would be fine if thats all you plan on having done to the car

 

for an awesome performance exhaust is to go 3 inch cat back and keep your stock size mufflers....its dyno proven to increase your hp.... and its not to loud!

 

in order to warrant a 3 inch exhaust on a 12a you need some decent forced induction happening, "its dyno proven to increase your horsepower" sounds like an ad for an ebay chip

 

Unless you have some wild peripheral port race car, go with a 2.5 inch exhaust on your non-turbo rotary, whatever engine you're running. Even DefinedAutoworks got 216rwhp out of their streetported non-turbo 13B-RE with a 2.5 inch exhaust.

Proof: https://www.rx7club.com/naturally-aspirated-performance-forum-220/216rwhp-streetport-13bre-sure-did-take-while-801325/

 

i would do 2.5, becuase with 3" you may have power loss