SVThaha

I've have been around the block with car modifications and for some odd reason have choosen to ignore the drivetrain...specifically rearend gearing. So as you could imagine my knowledge on this subject is very limited.

My car is a t-56 2001 WS6, spec 3 clutch, lightend flywheel, stock rearend with 3.23's from the 4L60E that was in before I converted it....
I just put a new motor in (forged rods+pistons) am running MTI stage 2R heads, X-1 camshaft. My guesstimation of rwhp is about 420.

The car goes in the shop next wednesday to get a NXwet kit (plan on spraying 150) installed and I am left with the plaguing question of how long the STOCK rearend will last?

I am an avid highway racer and at all costs avoid hard launching. I've been running 3.23's against guys with 3.73's and 4.10's but for some odd reason my car seems to pull like a bat out of hell against these high ratios(even from 1st gear)?! I am not quite sure why?! (This is against guys with nearly identical mods!)

*This is where I'm *

Within the next month I plan to get a moser rearend 33 splined axles and appropriate gearing....but what is appropriate gearing???

Theory:
With a 12bolt and my current mods; wont a low gear ratio, like 3.23, be extremely benificial in overall 1/4 mile time? You figure I stall hard of the line get a good launch, spray automatically kicks in after my 1-2 shift and all I have left is my 2-3, 3-4 shifts. I DON'T even have to shift in to 5!!!
With a higher gear ratio won't I be losing valuable time by shifting more???

I am not worried about streetability too much, although I would like to drive my car on the highway at cruising speeds w/o my rpm's hitting the roof. Once the rearend is in I plan to take the car to the track at least once a month. Weekly I drive the car about 300 miles.

Could the gearing gurus shed some light on this for me? What would you guys run with my setup? What is the best ratio to maximize my setup? Thank you in advance for any help.

chpmnsws6

iTrader: (70)

the more ger you have the longer you can stay in the power-band and the shorter each gear is. i personaly have 4.30's and wish i'd gone with 4.56's because they still semi dog off the line even dropping the clutch at 6400 or so.

just buck up and get a 12bolt/9 inch. you'll be happy you did and you'll be done worrying about it :drive

Clipper

It's going to be different on every setup. You're going to have to figure out what you're tach's gonna read through the traps. If possible, avoid the shift into 5 like you said. Personally, I'd rather carry 4th longer with a cam than with a tall gear.

where does your power level off? if it's too low to ride 4 through the traps, consider moving the grunt up in the powerband with a different cam. Once you drive the thing with the 4.10s, you'll do anything but give them up.

SVThaha

Alright 4.10's are looking very appealing, but why is that when I race against guys with 4.10's I seem to pull them hard off the line?? [I would say both of us had about the same amount of traction] Traditionally, aren't the larger gears suppose to be quicker off the line? or is it quicker overall?

My cam specs are as follows:
MTI X1 .592*/.571 230/227
cam oddly enough peaks at 5900 but has a extremely gradual decline. Shift light is set to go off at 6400.
With 4.10's won't I have to make a 4-5shift? Will the spray bring my traps high enough to make me shift anyway? Will the overall benefit of the gear change make lost shift time insignificant?

Ramair, with a gear as big as 4.30, doesn't that make cruising highway speeds nearly impossible at a reasonable RPM?

-thanks