Hi, so I'm looking at buying a Bonez Race Pipe. My pre-cats are shot and my actual cat has been gutted (removed, shaken, and pieces fell out). Right now my exhaust sounds like it's continuously farting.

So my question is; What's the difference between 86-88 and the 89-91? The S5 race pipe is like 10$ cheaper?

I'm mostly asking this because when my engine blows, I want to swap in an S5 TII motor. I understand with a turbo you need a downpipe, so I don't know if I should buy this race pipe...

I would like to get rid of the farts for the Apexi Dual N1 exhaust I was planning to buy with it.

Any advice? Thanks

 

https://www.rx7club.com/2nd-gen-arch...etails-813825/

 

welcome to the board.

this is just a guess on my part, so for the most accurate information, it would be worth your while to contact them directly.

if the pipe is replacing the cat, then the price difference may be for the backpressure pipe to open the auxiliary ports on the S4.

 

As diabolical1 mentioned the extra money is for a tube that's tapped into the race pipe to support the operation of the auxiliary ports on the S4. I know this because I bought one a few months ago.

Should you do a T2 swap this piece will not be reused as the turbo downpipe will replace it.