CowsGoMooo

Receipe for 500whp is heads on top of all of this too right? Head work gets real expensive doesn't it?

Darth_V8r

iTrader: (4)

Yup. Needs long tube headers first and foremost. It'll feel like you deleted plugged cats with that one change.

Another good bang for buck mod is a rod modded ls3 intake. You have a decent cam. Now it just needs to breathe.

G Atsma

The recipe for big increases in power is almost always a balanced combination of things. Intake, cam, heads, exhaust all play together in a coordinated way. It should start with heads. Then enough cam to "feed" the heads. Then exhaust, with enough "room" to get the gases out without too much backpressure. Then intake/injectors, because everything else just upped the demand for air/fuel. And so on...
Things can be switched in the above order, but you get the idea....
Oops, looks like Darth and I posted at once... lol
On edit- If the engine is an .LS3, forget the heads; they're big enough already for over 600HP

redbird555

iTrader: (14)

what? This has proven false time and time again. An a-b test done on a bone stock ls3 hours apart on the same dyno. A 2" header loses nothing down low and makes more up top

http://www.camaro5.com/forums/showthread.php?t=63640

redbird555

iTrader: (14)

not really. Bolt on ls3 can easily reach 450whp and there are lots of cam only ls3 cars with 500whp.

Darth_V8r

iTrader: (4)

Yup. LS3 heads flow a tremendous amount of air. They're not choking you at all. Milling for compression would help, but no need to port them out or anything.

A.R. Shale Targa

iTrader: (2)

Still THIRTY more degrees duration at .050" than the stock cam with ZERO increase in compression ratio....enough to shift the power band considerably
The factory dual mode axle back is actually quite a decent flowing system.....most just pop the fuse out so it's open all the time instead of only above 4K
My buddy noticed a decent jump on his stock Grand Sport by putting on LS7 manifolds, cats, and mids into the factory dual mode

KW Baraka

iTrader: (7)

If you absolutely must have 500 HP, well ported heads won't hurt.....but they really aren't the problem. Still.....a bit more compression, a bit more cam and a freer flowing exhaust would pay huge dividends.

I didn't say his cam wasn't a significant upgrade over stock.....I stated that it wasn't that huge for an aftermarket LS3.

Also, when I stated "a complete stock exhaust" was holding down power, I meant to convey that the stock exhaust manifolds were part of the problem. Your post about your buddy's Grand Sport bears that out.

KW

LilJayV10

iTrader: (39)

Dynatech's. Their stuff is great. They are about 20 minutes from our shop. We do all their dyno testing