za355tx

iTrader: (108)

My dad is just buttoning up his car and we're trying to figure out what type of exhaust setup he's going to run so I need to see if you guys have some info we don't.

Car is a 95 M6 Firehawk and here is a mod list.

Fully forged 383 with 12.3 to 1 CR
LE LT4 heads Flow about 285/200
LE LT4 manifold with 58mm Holley TB
LE 243/251 .597/.603 and I think 108 LSA (can't remember)
Kooks 1 3/4 to 1 7/8 to 3 inch collectors
42lb SVO's
ATI 6.75 balancer
4.10's
He plans to shift around 7k

Real question is with the kooks Y pipe...How much HP would we see with a custom Y with a better merge than the kooks Y? From there how much more power would he se by going to a 3 inch true dual setup?

Currently he has a 3 inch borla catback for the exhaust and he's trying to decide if the extra HP is worth paying for a custom Y or if he should go ahead and do a set of duals...or if the gain is not enough to bother with doing custom anything.

He wants this thing to be a monster but if the gains are only slight...then he may decide to just run what he has. Thanks a bunch in advance guys.

Zach

BizZzatch350

iTrader: (33)

I am running the same headers on my 93, I didn't order the Kooks Y but rather had one built locally. It's a 3 Inch stainless, Vibrant bullets after the collectors in to a merge collector. I plan to reuse it on my 398 set up with the Borla Cat back. Patrick G had a write up in one of the LS1 section about Y pipes, basically copied that same idea on my LT1.

bufmatmuslepants

iTrader: (3)

That's a very well put together build, should put up great numbers. Here's a good thread.

https://ls1tech.com/forums/generatio...s-exhaust.html

https://ls1tech.com/forums/conversio...y-ls3-rx7.html

SS RRR

iTrader: (2)

If track times are being seriously considered it'd probably be a better idea to go with a steeper gear. Perhaps a 4.30 or maybe even a 4.56 with a 27" Hoosier QTP tire. If it is going to see mostly street then either a 4.10 or 4.30 would do nicely.

383lt1z28

gonna have my head milled and ported with a c/r bumped from 11.4 to 12.5 builder told me to go w/3 in true dauls I'm running a fully forged 383 also only warning is it is loud but I dont care offensively loud ha ha he he ha ha ha

nitrous2fast

iTrader: (2)

You should just go to a 2.5" dual setup. 3" is way over kill.