Im going to be running essnetially a hahn stage 2 (hahn stage 1, but bought my own spearco fmic, turboxs bov, and mbc), and i was wondering what size dp and exhaust would perform the best. i dont plan on running a cat either, no emissions in florida anymore.

ive heard some people tell me to go with 3" turbo-back, some 2.5" turbo-back, and some 2.5" dp and 3" exhaust. i figured i would ask you guys since you actually have experience w/ boosting the 420a, hehe

http://www.asog.net/phantom

Hey as soon as i save up money im getting a 2.5 dp then opening up to a 3" after the flex joint then 3" cat, 3" piping and apexi N1 muffler. I heard from my local shop a 3 inch exhaust isnt really necessary for a stage 2 but it wont really hurt anything, and its nice to have if you are upgrading other engine stuff later. He said also a couple extra hp and torque with 3" over 2.5. hope that helps
95 GS HRC Stage II w/FMIC

cool thanks.

any other opinions? thoughts?

http://www.asog.net/phantom

Whatever you do, make sure you dont get a catback and a downpipe only, make sure you also replace the pipe that runs from the downpipe into the cat(or where the cat used to be if you opt to remove it), the owner who had my car before me had a nice expensive 3'' greddy catback, and a 3'' HRC downpipe, but from the downpipe to the hollowed out cat was stock, I'm sure thats not very good on high boost, huh? and make sure everythings mandrel bent of course.
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Brad Rickard
98 GS HRC Stage V (nuff said)

right, well i plan on redoing everything from the turbo back, dp and all...

wondering if a 2.5" or 3" dp would be best tho. im leaning towards 3" exhaust.

any thoughts on the dp size? and anyone disagree with going with 3" exhaust?

http://www.asog.net/phantom/

hey super does anyone make that pipe aftermarket that you are talking about? if not, what did you use?

You need to have it fabricated at a local muffler shop, have it madrel bent.
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Brad Rickard
98 GS HRC Stage V (nuff said)