I'm getting my RMR catback exhaust installed this Friday, but I'm also considering their DP as well. My question is... will I get any performance gain if I keep my stock cat on? I'm not planning to put a testpipe or any high flow cat on just yet.

 

i would imagine so

i think i remember somebody saying they got a little hp with just a downpipe and the rest of the system stock

 

What kind of power gain can you expect from a DP with stock cat? I'd get it if there's at least 7-8 or more horsepower to the wheels.

 

i was under the impression that the stock cat is actually pretty good, that it looks like a high flow unit...

you should be substantial gains with a DP and the catback...

 

You might get a slight exhaust leak because of mismatch sizes 2.5"stock cat and 3"dp & 3"catback.Which size gaskets are you gonna use 2.5" or 3"

 

I have the DP and the flange is a perfect match up to the stock cat.

 

Contact Daryyl from Ultimate Racing and buy their straight pipe. Youll get no CEL and it flows like a ****. The cat is more of a restriction than the DP.

There is NO place in an exhaust system for kitties =)

 

i was plannin on gettin a custom 3'' downpipe... but now im hesitatin... im goin have to get another custom 3'' downpipe after my turbo upgrade later... so im thinking about maybe going with the hks 2.65'' for now bcuz it will give me more torque than the 3'' while runnin 19 psi all the way up.... and im a street person... not really a track person

 

what are yallz thoughtz???

 

Does anyone who if HKS DP fits without removing the lower tie bar?

 

Dont know... you can also put some spacers on them though so its really no big deal... The Ultimate Racing 3" clears is by far. They also make a 2.5" that is a TON cheaper than the HK$

 

I want to fit a 3" DP but will it fit on the stock cat without trouble? Will I need anything adapter to have it fit perfectly? Also will the 3" cat back fit on the stock cat also with out any trouble?

 

Yea you should be fine if you go that route. Even though it will be restrictive, it will still give you some gains. As long as the 3" DP you are using has a flange that looks like it will bolt up to the Cat, youll be all good. Its pretty much a universal looking flange.

Go ahead and buy some new gaskets from the Stealership though. When I took my cat off, the gaskets came with it! Always use new gaskets when you can!