s4amodio

I am trying to make a decision on the exhaust set up and leaning towards 3'' downpipe/ mid pipe and test pipes with oem (stock) catback . Would this set-up completely defeat the purpose due to restriction , what would be the difference in hp gain than having full turbo back . Anyone have anything similar ? . Any opinion , input , first hand This what i am leaning towards http://jhmotorsports.com/shop/catalo...edc3f9952ead46

jamesdmanley

i dont see any reason to do d/p before catback

s4amodio

1- The real gain is with downpipes due to the restriction of the pre-cats on the oem dp's and cats , 2- I am not looking for sound only opening up breathing and increasing spool at least thats my reasoning behind the idea .

donromani

If breathing is the goal then go ahead with the d-pipes with 3 inch diameter. That will let you go with a 3 inch pipe on the cat back in the future as well. In the meantime you can just get a 3 to 2.5 adapter sleeve, but I would go ahead and do the entire system all at once if you can afford it. The catback is no prob to remove - it's the dps that take the most time.

You won't really see gains from the larger diameter pipe IMO, at least not until you're moving more air with k04s. Getting rid of the precat is where your biggest gains will be, both in removing restriction and getting rid of the heat the precats radiate into the engine bay.

jamesdmanley

stock catback merges into 1 2.5" pipe. you can get a nice quality quiet dual 2.25-2.5" catback for around $300

donromani

that is a good deal. do you have a link or vendor name?

jamesdmanley

got mine on a group buy. ill see if i can find a link to the manufacturer. they came out of cali. probably made in china, but the quality is nice and the fit is decent

jamesdmanley

looks like the thread is gone, but it looks just like the xs power and ssac exhausts. think i paid about 300 shipped for just the catback

kwazimodo

I had the exact setup you are describing on my car a year back, before going for the full 3.5' catback.
The main bottlenecks are the cats, and removing those will not only prolong the life of your turbos but also give you a couple of hp on top of that. Catback will most likely not give you any massive gains on a stock/chipped or even a K04 car.

jamesdmanley

i still think 3" d/p's are way overkill on anything with stock turbos. i would buy a catback and do piggies, but thats just me. why run 3" d/p's on a stock catback? it just doesnt seem to make sense to me