ZL1Killa

iTrader: (17)

guys/gals, I have the chance to purchase a moser 12 bolt for my car and I have currently been happy with my 3.73 gear ratio as I do not have to downshift from 6th gear to pass anyone on the highway, I however would like to pick up some spool time.

stick with 3.73 gear OR go with 3.55 & probably still not have to downshift... OR go with 3.42 & downshift...

in reality, the small difference from 3.73 to 3.55, is that even worth considering? Being a rear mount & loading & turbo application, I would think any difference would be exaggerated with a turbo car.

Thinking 3.55 ratio now.



Also,
Doing forged components in my ls1 & changing out from ls1 to ls6 heads...
(copied from Tony Mamo under Internal engine)
INTAKE FLOW

Head…………Int. Valvelift…………………..........Runner
…..….200….300….400….500….550….600…….Volume…………Comm ents……….
“C”….131….189….240….275….287….282………221 cc’s…(LS1 castings)
"W"...141...206...256....299....315...324..... 236 cc's ...LS6 Casting/Good#'s

Assuming I stick with flat top pistons, what would my new compression ratio be?

With the new ls6 heads, what piston should I go with for a 9.5:1 compression?



General question, being that I'm going with forged internals & building it to hold 800RWHP & TQ; what compression ratio should I run? I want to run on pump gas & 12psi of boost.

OUTLAWZ RACING

iTrader: (9)

I think a 15 cc piston would do it. But are why not use 317 heads? They are the same just 72 cc bowls. Many have push the 317 to 800+ including my self.

TurboAv

iTrader: (6)

I'm using -16cc dished pistons, Felpro MLS head gasket that is .050 compressed, pistons .015 in the hole, and 62cc 243 heads on my 370(4.03x3.622). That is giving me 9.26:1 compression. Just do a search for compression calculator and plug in the numbers. What static compression you run depends on whether you are going to run methanol or not. You also want a efficient intercooler. My opinion is to keep it around 9-9.5:1 if you don't want to run methanol. Up to 10.5:1 if you want to run methanol.

ZL1Killa

iTrader: (17)

i was thinking 9.5 : 1 compression.

As I can get the ls6 heads real cheap, thats what I was going to go with as it would still be an upgrade from the ls1 heads.

The Fugitive

iTrader: (6)

look on here you can get some 317's for about $250+ add some dual golds and you'll be set.

TurboAv

iTrader: (6)

The LS6 head is the same as the 243 casting, which is the same as the 317 casting. The only difference between them is the sodium filled valves from the factory on LS6 heads and the combustion chamber size.

ZL1Killa

iTrader: (17)

ok, got the details.

66.67cc ls1 10.1 : 1 compression
64.43cc ls6 10.4 : 1 compression

As I'm going to run between 8-12psi of boost, should I stick with the 10.4:1 compression or should I get a few cc dished pistons to reduce the compression??
(running pump gas)

spaz1

iTrader: (9)

Go 9:1 c/r or 9.5:1 if running meth... I'd say -18cc pistons .051 head gasket and 72cc 317 heads, use a callies 4" stroke crank too...
gears like 3.25ish should work good for spool.