An RX7 would run better with 2 twin exaust pipes and no cat or with a single exaust pipe and no cat. I have twin pipes but I am thinking of changing them to a single pipe and no cat.

 

It doesnt really matter. If your going to run a turbo 3'' pipe or bigger, single or duel it don't matter. Running an N/A it WON'T matter because your not pumping alot of air mass anyways. a 2 1/2 pipe or bigger, single or duel, it don't matter. plus duel is just more weight.

 

i got 2 and 1/4 from stock manifold back no cat no nothing

 

their is no major difference between power. a big difference in noise. turbo you want to stay a single straight pipe to prevent boost creep. n/a it really doesnt matter. getting rid of all the cats and resticve header is where you get the power.

 

Huh? Why would a single straight prevent boost creep? It flows slightly better.

 

to get rid of any uncessory backpressure

 

A single exhaust will always produce more power because it allows for scavenging, which is a big power producer for the Rotary.This is why the 3rdgen has this setup.

Your best setup is 2" piping make it 3"s straight from the block then 4' then collect it. then run 2 1/2 piping, you can get the 2nd gen rx7 exhaust down to 1 bend after the header collecter. and put the muffler as near the rear as possible. Use a very high quality stainless steel muffler with ceramic or steel packing, eveything else will burn out within 100 miles. or blow apart from the backfire and flames that this setup produces.


I can say this is true as we made 4 different headers for my buds rotary rail and this design was the best for low end and top end power for the 6 port 13B which ran a 12.6

 

This statement is incorrect. removing stock parts does this but the single exhaust doesn't prevent creep. Creep comes from wastegate size.

 

Thank you. It will actually only help it creep. A stock design will not, but throw a single 3" no cat exhaust on and see what happens.

 

So its better for NA and turbo to stay single no cat