Are there any aftermarket exhaust systems that are cat back only (keep stock catalytic converters)? AWE claims that there is only a couple of hp difference between 100 and 300 cell cats, so i wouldn't imagine it would be a big difference to keep the stock cats (400cell i think). It seems like this would eliminate the check engine light problem. I know for other cars such as mustangs there are systems like this (ex. borla). I'm wondering why i have never heard of systems such as this for the 996tt.

2003 996tt (soon to be modded)
2004 x5

 

I'm running the AWE 300 cell exhaust with no problems. I couldn't be happier with this system.

 

We have done tons of AWE systems here on 996TT's, and never have we had a CEL with that set up. You have nothing to worry about.

 

So call Jay up and ask him about his beautiful array of glistening, power enhancing systems that will make your Turbo sound like it's meant to. I wouldn't mind living in Brandywine's performance shop it's so nice (not to mention a random CGT or 911 stuck in there).

 

you only need 100 cell cats for no CEL's and you cant keep you factory cats they are part of your muffler.

 

I have 100 cel cats with my PSI exhaust and have not had any problems or lights.

 

I don't believe this, never have. 100 cell cats are quite pricey, for a reason

 

What data would you like me to provide to make you a believer?

 

I would like to see a 700HP car with both 997 100 cell racing cats and any 300 cell cat on the same VERY free flowing exhaust as a compairison.

There must be additional restrictions on large HP cars with a big tube exhaust with the only variable being a more restrictive CAT.

 

How about a back-to-back dyno, same car, same exhaust (except for the cats of course) using a flashed K24 car (530 hp or so.....right in the middle). Need back pressure measurements as well. Videotaped of course just so we can also get an idea of sound levels.

You have a good product, but every other exhaust guy I've bugged thinks there's more of a difference than 3 hp (I think thats the claim on your website).

 

Europipe makes a system with 400 cell cats that is TUV certified for the German market. It is sold by 9ff. It adds about 7HP over stock vs. +17HP for the 100 cell Europipe.

 

That's exactly the claim.

We don't video every dyno session, but I have our engineer looking for test results.

Also, we offer these as a no cost option if somebody HAS to have them. They are no more expensive than the cats we currently use.

Have any of your "exhaust guys" actually done testing, or are they all just speculating?

 

I would like to see that comparison also.

 

Lets put it this way, some of these guys are major competitors....so yes they test......the others are drag racers with practical experience.