There is a local performance shop that i work with alot, and I was thinking about having them custom make me a track pipe from the cat back. Is this to much for 325 e36, i'm going to be auto crossing and I need a new cat back set up any how, any power gains, is it way to loud.

There is a local performance shop that i work with alot, and I was thinking about having them custom make me a track pipe from the cat back. Is this to much for 325 e36, i'm going to be auto crossing and I need a new cat back set up any how, any power gains, is it way to loud.

Well, I don't know what the price of a custom trackpipe will be from those guys, but check out the Active Autowerke (http://www.aatuning.com/exhaust/default.cfm) trackpipe, which I have, and which fits your car as well. I have their headers installed as well as their catback, and you really can't even tell sound wise until you're at WOT. The gains, at least claimed by AA, for the M3 are rather significant. Check it out.

just what i wanted to know, thanks,

just what i wanted to know, thanks, wait I lied. what I'm thinking about doing, is a little different than what AA sells, I was thinking keep the two cats up front and from there go straight dual all the way back.

What class are you running, is this allowed?
If you are keeping any cats in the system, dont bother making it straight back after, it wont make much of a difference.

Any off the shelf quality catback will be enough...KK headerback is the only next step worth investing in really.

weight savings will be a big advantange if you make it straight after cats (i'm guessing you're looking at BS)

What I think would be even lighter, is a collector of the two pipes right after the cats and running them as one (probablly 2.5") back.

No one has anything that joins the exhaust on the market. There must be a reason, but I'm still reasearching to find one. I know the exhaust is split off of the engine, but that doesn't mean it will hurt performance.

KK headerback is the only next step worth investing in really.

The AA headers and header back system isn't a bad setup either. The KK stuff is almost too thin and fragile for anyone not racing at the very front of a competitive class.