TESTPIPE OR GUT THE CAT?
 

IM TRYING TO DECIDE WHICH WAY TO GO. IS A TESTPIPE REALLY GOING TO BENIFIT ME MORE THAN JUST REMOVING THE GUTS OUT OF THE CAT? OR SHOULD I NOT EVEN BOTHER WITH THE WHOLE THING CAUSE THE POWER GAINS ARE NOT NOTICEABLE?

RE: TESTPIPE OR GUT THE CAT?
 

is your car a manual or an automatic?

RE: TESTPIPE OR GUT THE CAT?
 

Caps lock is cruise control for coooool...

Noise is really going to be the only difference, your turbo will spool up faster, assuming you have a 1.8/2.0T engine. If you have a 2.7/2.8/3.0/4.2NA, I dont know because I wouldn't buy one of those to tune.

RE: TESTPIPE OR GUT THE CAT?
 

Gutting the cat will not be the same as a TP. Because a TP is the same inside diameter the whole way. If you gut a cat, then the middle part will be wider and then collapse down to the diameter of the downpipe again. This will cause all kinds of funky things to happen with the exhaust gasses.

RE: TESTPIPE OR GUT THE CAT?
 

I had friends gut the cats of their old beater pickups, never had issues, but it would NEVER be something I would do to my car. But now you have me curious, what kinds of funky things happen? I'm thinking reverse-effect of an airbox on a car, but how would that effect the engine? Loss of backpressure?

I dont know the least about it, and since I have strict emissions testing (Vermont), I can't do it anyway, but I'm still curious.

RE: TESTPIPE OR GUT THE CAT?
 

No idea what it will do as I don't know ofanyone who tried it. It may be different on a non-turbo car, too. Basically, the exhaust gasses will have all kinds of turbulance as they expand where the middle portion is.. and then have to get restricted again before entering the downpipe. This may be no big deal if the cat was further back in the system or on a non-turbo car. But since it's right after the turbo, I'd venture to say that whileI have no idea, in theory it could cause some problems or at least weird spooling.
One thing is for sure... I wouldn't try itand doubt many who want to mod a reliable turbo'd car would.
One thing I've learned is the word "cheap alternative" and "reliable fast A4" can't ever be used over the long term.

RE: TESTPIPE OR GUT THE CAT?
 

Yup, I almost bought an "OEM Lip Spoiler" but read the AudiZine review, now I am either looking at a full on spoiler (not one of those Nasa wings, ick) or a true Audi OEM. Both are not cheap lol

But that makes sense about the weird spooling. Sounds like it'd be nothing but problems, and testpipes arent that expensive anyway, just go with one of those...

RE: TESTPIPE OR GUT THE CAT?
 

Thanks for all the info. Its always appreciated. I have a 1.8t fwd manual btw ,and now i will buy a test pipe instead. The word cheap is kinda harsh i would think that everyone would like to save money if they could ,and if they dont try then i guess they are just rich then.