05-05-2005, 05:09 PM
I can think of a good reason to delete a cat in a street car that you're modifying. I'll use the WRX for example.
If you replace the turbo and / or the blow off valve, it is a REALLY good idea to replace the uppipe with a catless version. Cats in the uppipes will occasionally melt due to excess fuel that builds up on them (from the rich conditions caused between shifts of an aftermarket BOV) and can disintegrate into the turbo which can then break and fuck up your engine. It's a good idea to preserve the investment you have in your turbo and your engine to buy a catless uppipe (or remove it and gut your own). It's probably a good idea to run catless with an aftermarket turbo anyway to promote better spool and reduce lag.
FWIW, I run with a still catted uppipe until the turbo upgrade and 1 high flow cat that's pretty good at doing its job.
If you replace the turbo and / or the blow off valve, it is a REALLY good idea to replace the uppipe with a catless version. Cats in the uppipes will occasionally melt due to excess fuel that builds up on them (from the rich conditions caused between shifts of an aftermarket BOV) and can disintegrate into the turbo which can then break and fuck up your engine. It's a good idea to preserve the investment you have in your turbo and your engine to buy a catless uppipe (or remove it and gut your own). It's probably a good idea to run catless with an aftermarket turbo anyway to promote better spool and reduce lag.
FWIW, I run with a still catted uppipe until the turbo upgrade and 1 high flow cat that's pretty good at doing its job.
Posting in the banalist of threads since 2004
2017 Mazda CX-5 GT AWD Premium
Past: 2016 GMC Canyon All Terrain Crew Cab / 2010 Jaguar XFR / 2012 Acura RDX AWD Tech / 2008 Cadillac CTS / 2007 Acura TL-S / 1966 5.0 HO Mustang Coupe
2001 Lexus IS300 / 2004 2.8L big turbo WRX STI / 2004 Subaru WRX / A couple of old trucks
2017 Mazda CX-5 GT AWD Premium
Past: 2016 GMC Canyon All Terrain Crew Cab / 2010 Jaguar XFR / 2012 Acura RDX AWD Tech / 2008 Cadillac CTS / 2007 Acura TL-S / 1966 5.0 HO Mustang Coupe
2001 Lexus IS300 / 2004 2.8L big turbo WRX STI / 2004 Subaru WRX / A couple of old trucks