ok so i was just looking at a ss/sc thread on this but would like the tc guys' opinion

i am about to get a 3" catless downpipe from CIA and was wondering, how it would it sound having a 3" catless dp with stock exhaust...? any info/experiences/vids i will do a google search while i am waiting for responses

 

no cat for sure.

 

what would the HP difference be between catted and non catted?

 

Depends on mods, but CIA flow-tested their high-flow cat, and it's more than enough for anything the stock turbo can produce. Either the high-flow or no cat at all should net you a decent gain in hp, but there is not a significant difference between the two. Just ask yourself how legal you want to be.

 

not very? lol

 

So if you got a high flow cat, you would still be legal and pass emission testing? If so, why would GM put two cats on it if it could be legal with one high flow cat?

 

Likely GM has to pass much stricker emissions testing than your local testing setup. When 2 cats are used, the closest one is for cold start emissions, and the other is for at temp emissions.

 

go no cat

keep the catted stocker to swap in for inspection/emissions

only takes 30 mins or so to swap

 

prob less for me cause i have multiple lifts availible

 

go no cat, None of my cars have them.

 

hows the sound difference? Im also debating...and will most likley decide on which has the better sound. if its not a major difference then ill just go catted

 

Its much louder without a cat. I went catless because all the do for emissions here is plug you in to obd2 and as long as there are no codes you're ok

 

Go With High Flow, Prevent Boost Crepp With That, Especially In The Winter, Unless You Port Your Wastegate Or Manually Control Boost Or Deadbolt The Turbo

 

Dude go catless.that's how I have mine.but its too loud but felt a difference and u can hear ur turbo spooling loud

 

Catless? Think of the children...

 

rofl

 

catless is fking loud lol

 

I used to think that the highflow cat was good enough. Not anymore. Honestly, I felt no difference between the stock DP and the Hahn catted DP until I gutted the Cat. Now it spools up faster and it seems to pull better throughout the entire powerband. Still looks legal and no codes in 200 miles of driving. The biggest airflow difference in these cars is the intake by a huge amount trust me.