Both me and my friend have GS-R's, his was turboed by former owner and came with a Thermal 3inch turbo back exhaust fitted on to DC headers, my question is if I want to swap this onto my car which has stock headers will it be a direct fit? Or do I need an adapter?

 

Definitely need an adapter, and flanges for the cat added.

"Stock headers"? No such thing. The GSR came with a cast manifold, and it's less than 2.5" ID at the outlet.

 

Wait so I would need to weld different flanges on? I think they still had a cat on his setup. And wouldn't the headers that came with the GSR be considered "stock" perhaps not stock for Integras, but among the GSR's it should be right?

 

adapter maybe.
another cat with the correct flanges might help or a jdm type r exhaust will bolt up to most aftermarket headers.
i would get a jdm type R complete exhaust system. makes smog easier and performs great

 

What I was trying to say was:
1) If there isn't a cat, you'll want to find a way to get one in there. Flanges are much better than welded in place. Generally, a 3" turbo exhaust won't have bothered with a cat, so my initial assumption was that there isn't one.

2) The GSR didn't come with headers (we'll leave the header vs. headers debate out of this), it came with a cast manifold. Terminology nit picking, feel free to ignore.

3) The stock exhaust manifold is less than 2.5" ID in size. No matter what, you're going to need to adapt the size if you want to use a 3" exhaust.

 

Yes it is header, sorry about that, but what is the difference in the header vs. cast manifold, I mean I would think the LS header is cast as well?

 

Tube steel vs. cast piece

Header:


Cast manifold:


Yes, the LS manifold is also cast.

Again, it is terminology nit picking. If it still doesn't make sense, don't worry about it. All of the other points are much more important. And if you do have a tube steel header on there, then it isn't stock, which was all I really wanted to convey.

 

ooo gotcha I see the tubing vs. cast, yea its def a stock manifold.