First, the facts: I have a 1996 GSR, currently with an AEM CAI as the only mod. The car is to remain N/A.

Now, the pondering...
I've been looking at the comptech header, as for pricing I suppose I'll just have to shop around in about a month when I get the money, but I was wondering what the size of the collector was on that? I didn't see it anywhere when I searched. I want to buy all the parts for my car (header, h-f cat, cat back exhaust) one after another and install them all at the same time, makes replacing gaskets and and everything easier if all at once. Now, will the comptech fit the advanced technologies hi flow cat? I don't know what the size of the piping is on the AT cat, so I have no idea. I chose them because of being smog legal here in CA, and I've heard good things about them. However, if anyone has any experience with them, I'd love to hear it. Also, what size exhaust would fit the cat, to complement the cat/header setup? I would want it to be all as uniform as possible, and I'm assuming that 2.50'' would be ok, but really, I have no clue as to the sizes, so thats just a guess.

So really, if you have any thoughts or input on any of this, feel free to share, I'd appreciate it

 

Paragraphs own you.

But back to your post. The collector on the Comptech 4-2-1 is 2" Now when you buy your AT cat, you're going to need flanges welded on. Just get the proper sized flanges to fit your header and catback system.

With the catback system, if you're just going to do mild bolt-ons then a 2.25" or 2.36" system will suffice. If you plan on making more than 230whp, then look into a 2.5" catback.

 

230 whp? I disagree.

I would go with 2.5" if you plan any major upgrades, ie headwork, cams, etc.

 

-1/4" up to 210HP @ the flywheel (about 180-185 whp)

2-3/8" (60mm) up to 235HP @ the flywheel (about 200-207 whp)

2-1/2" up to 265HP @ the flywheel (about 225-235 whp)

2-3/4" up to 325HP @ the flywheel (about 275-285 whp)

3" big for big HP (Forced Induction: > 275 whp)

From Team-Integra

 

link to the article <-- spoontypeone is referring to..

 

2 3/8'' (60 mm) sounds best to me. Where can I aquire these flanges, and how much (in general) does it cost to weld them on? A friend of mine has an arc welder, so I can use that as long as it is not aluminum.

Is having an exhaust and or cat LARGER than the collector on the header most efficient? Wouldn't it be best to have it all the same?

 

Anyone?