Hey, please don't flame, im new at this. I've spent hours reading, but there are still unanswered questions. I recently bought a APEX N1 catback for my '98 RS. It's diameter is supposedly 2.36". When im purchasing my high flow cat, and headers, should the collecter and the cat also be 2.36"? My friends are telling me yes, yet I cannot find websites that sell you different diameter headers, so far just 2.25 and 2.5. Any tips would be great .

 

What are you trying to do with the motor? What are your goals and expectations? Please provide more info.

 

Since you already got a 2.38" Apexi system, you definitely should get JDM 2.5" collector header and 2.5" high flow cat. Dont get 2.25".

 

The apexi exhaust is 2.5" from the outside diameter, if you measure its inner diameter it is 2.36 same goes for headers and all. The inner diameter would be smaller. Go with the 2.5" cause the inner diameter would be a bit smaller and you would be set with the whole system around 2.36" all around.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by silvrintegra &raquo;</TD></TR><TR><TD CLASS="quote">
The apexi exhaust is 2.5" from the outside diameter, if you measure its inner diameter it is 2.36 same goes for headers and all. The inner diameter would be smaller. Go with the 2.5" cause the inner diameter would be a bit smaller and you would be set with the whole system around 2.36" all around.</TD></TR></TABLE>

It's 2.36" OD. Exhausts are measured (and advertised) in OD.

 

I plan on doing I/H/E then saving up for an engine rebuild. When I do the engine rebuild i'm also gonna install a turbo, however until then, I want NA diameter exhaust. So if I get some GReddy headers and cat that are 2.5" they would fit right? Or would i need some kind of connector?

 

Also,could anyone post some headers that would compliment my APEX N1 exhaust? It would be greatly appreciated. And APEX headers are not for my car, its not a GS-R

 

Bump

 

Would I have to do any welding also? Or would it all bolt right up if I got some GReddy headers with a 2.5 collecter, and a 2.5 cat!?!?!?

 

Greddy doesn't make a 2.5" collector header. If you're not going to keep the N/A setup for long, then just get any of the 2.0" collector headers out there. In that case I'd get the Comptech header. It's the only 2" header that is stepped.

 

Alright, sweet thanks . Yea I decided that after being flamed by 30 posts on TI, but some posts had good info . Yea, so is a 2" comptech then a 2.25 CarSound cat, and then a 2.36 catback sound good? I guess the increasing size kind of pulls the exhaust a little more?

 

increasing the size from headers to cat to exhaust...is better than decreasing it.

 

Sweet . Thanks guys, u are WAY nicer than TI forums

 

you just have to be capable of reading around on ti.