wht97ws6ta

Well last night my trans am eat the carrier on the starting line on 3rd pass. Air was bad but track was decent. Was doing 1.61 short times with a 7.56 1/8 and a disappointing 11.90 1/4. Anyhow I'm running 4.11s now or was. Debating on what to go back with. 4.11 worked great with stock motor and seem to be OK with built motor. Car made 423 HP at the wheels @ 6700 368 tq @ 5200 rpm. My converter flash is 3800 rpm and it crosses the 1/4 at 6700 rpm in 3rd. I was thinking of going back to 3.73s but am a bit torn. What's your thoughts.

Corvett z07

iTrader: (2)

I know a friend with around the same numbers that you're laying down and he's going with 4.10's (he currently has 3.73's.) The only bad thing is that he's never actually ran with 4.10's yet, he's still getting some fine tuning done and whatnot so I can't give you any info about that atm. IMO I can't discern which would be better for your setup either. It's possible either way, you're setup may taste better with the 3.73 with the lower torque and higher horse. Yet on the other hand 4.10 might give you that extra bit on the 60'. I'm rambling my thoughts here and keep bouncing back each ratio on which would be better for that setup. O.o

wht97ws6ta

I'm thinking about splitting the difference with some 3.90 gears. That would still give me a lot of torque multiplication in low gear and should drop my rpm at the stripe by 300 rpm. One thing that I wanted to try was locking the converter at around 6300 in 3rd to see if converter is still a little spongy on the big end. I never got around to trying it.

nitrous2fast

iTrader: (2)

Heck a set of 3.42's might be in order. Stronger and should make the converter flash a few 100 higher further in the power band. I have always liked the 3.73's though, a good all around gear.

bowtienut

iTrader: (1)

Going back to anything less than 4.10's will only slow you down.
The only upside would be a larger pinion for better gear strength.
What tire size are you running?

wht97ws6ta

Tires are 275/40/17 MT drag radials. I don't think I will go back to 3.73s. May try the 3.90s and see how they do. That should bring the rpm down 300 rpm at the stripe and still recover well on the shifts. I really like the way this converter acts so maybe 3.90s won't shoot it in the foot to bad.

bowtienut

iTrader: (1)

Originally Posted by wht97ws6ta:
"..... 423 HP at the wheels @ 6700....... and it crosses the 1/4 at 6700 rpm in 3rd......"
That right there says it all. The other arguments presented in this thread are flawed.

Once again, if performance is your goal, why would you want to take gear out of it?
But hey, it's your car
Maybe you have other reasons than performance for wanting to change the rear end ratio.

wht97ws6ta

Biggest reason I was thinking of going with the 3.90s is because the motor makes such a flat torque curve that I think the difference will be negligible. I notice from a 2nd gear dig the car seems to pull strongest around the 6300 range. The power peak is very close to the same from 6300 to 6800 then flops.

pancho toco loco

iTrader: (8)

Honestly your splitting hairs. Go with what you feel is best