I have an 89 TII with a dp (unknown), stock main cat, and the apexi n1 catback.

I also have a 90 GTU (all stock).

I was wondering if I could take the cat back off of the GTU and bolt it to the stock cat on the turbo car so I can sell the A'Pexi (because I plan on getting an RB catback).

I believe my question could be summed up as "Do both the turbo and non-turbo models of the S5 body style have the same exhaust from the catback, or atleast one that connects the the same cat the same distance from rear bumper.

Yes I searched and I could not find measurements, I used a tape measure and I'm guessing it will work if the offset on the cat is the same on either Y pipe. Is the diameter of the tubing different?

 

Nobody?

 

yes

 

So turbos and non-turbos share the same y pipe diameter and everything?

 

It must be my downpipe, because my y pipe off the gtu using the stock hangers is like 3-4 inches away from my cat. I'll just get some tubing welded with flangers so I can bolt the cat and y pipe to it.

 

Had a muffler shop make me a little 3 inch long pipe. Bought gaskets to go inbetween the stock cat and the 90 gtu na pipe. Sounds awesome. Way better than the A'Pexi fart cannon. Now.. who wants the fart cannon so I can save up for RB?