I just finished rebuilding my engine, and now im fixing up all the odds and ends. I was planning on running 14-20psi now that everythings built, and I plan to upgrade my manifold eventually as well, but I was wondering if a bigger downpipe will increase performance any. Right now, it's about 2.5 inch diameter. Im running the greddy SP exhaust with a straight pipe as well. Suggestions?

 

There are a lot of differing opions about this..depends on what you want out of the car

 

i bigger downpipe in help the turbo spool faster, but modifation is required to usally run a 3inch so it depends on wat you want to do, 3inch will be better but you might have to give up your a/c

 

The only downside to a bigger exhaust on a turbo car is noise. If you don't mind the noise then go bigger.

 

who makes 3" ones? Or are they usually custom fabricated?

 

2.5" Flared out to 3"....what i have...

 

ffgeoff makes really pretty downpipes.

 

I dont really care all too much about noise considering its an LSVTEC engine and its already louder than normal, but Im looking to get alot of power out of it. Ill probably look into getting a 3 inch one made in the coming weeks....thanks for the help!

Oh yeah...I dont have ac or PS anyways, so that won't really make a difference either.


[Modified by eg2turbo, 6:10 PM 11/26/2002]

 

3 inch is good. i took my car to an exhaust shop and they mandrel bent the downpipe and welded a flange on it to fit my turbo. cost me 65 bucks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TeStUdO &raquo;</TD></TR><TR><TD CLASS="quote">3 inch is good. i took my car to an exhaust shop and they mandrel bent the downpipe and welded a flange on it to fit my turbo. cost me 65 bucks.</TD></TR></TABLE>

What!?! 65 bux?!?

You could easily double (or triple) your money if you resold them!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TeStUdO &raquo;</TD></TR><TR><TD CLASS="quote">3 inch is good. i took my car to an exhaust shop and they mandrel bent the downpipe and welded a flange on it to fit my turbo. cost me 65 bucks.</TD></TR></TABLE>

Are you sure it's mandrel bent and not crush bent? Mandrel bending equipment is neither cheap nor easy to operate. I've never seen a muffler shop with a mandrel bending machine and can't imagine one doing a DP for $65 even if they could. I'm thinking they may have fabbed it from 3" u bends, but that's still a hell of a deal. Where is this shop and did you get a special deal or can anyone get in on it?