CHRISPY

Hi guys,
I have a quick question:
Do you guys think 3.73's in a six speed is fine for autocross/road racing or would you recommend 3.42's only? This is for a 430-440RWHP six speed car.

thanks!

trackbird

iTrader: (4)

At that power level, I'm not sure you need the torque multiplication of a taller gear. But, 3.73's work well with a 6 speed, it just seems like you'll spend alot of money for a fairly small gain. Just my thoughts....

CHRISPY

I am getting a stock rear with 3.73's already installed but I have a set of 3.42's lying around I could throw in.

thanks!
Chris

mitchntx

iTrader: (14)

I apologize for the size of this file ...

http://12.213.170.218/mitchntx/TWS_Glenn1.wmv
36M

It's a couple of laps around TWS ...

Clost to the beginning, there is a black Firehawk ... Hawk#46 is what he goes by. He is putting down ~430 at the rear wheels.

If you notice, after they come off of the front straight the first time, there is a LONG sweeper to the left, a short straight and then a 90* right hander.

It's off camera, but notice all the tire smoke as he lights up 315 racing slicks on corner exit? He's running 3.73s ...

I run 3.42s and shift 4 or so times LESS on the same track than he does. His times are a couple of seconds per lap faster than mine, but he has 200lbs, bunch of suspension and 75 HP on me.

All this to say I think 3.42s is a great gear for open tracking and AX ... a lot of gear and carries a lot of speed ...

CHRISPY

Cool thanks for the info!!

ibjamin

iTrader: (6)

I disagree. 3:42's work fine (it's what I have) but 3:73's would work better at most tracks. Lots of moderate speed corners are taken in 3rd gear (2nd would really rev). 3:73's would allow you to take the curves at the same speed but exit in a meatier part of the powerband.

For example, last weekend at Gingerman my friend had 4:10's in his 99 Cobra on Friday night. He decided he didn't want to have to shift into 5th on the straights (for a very short period of time). So he installed his 3:73 center section (IRS). Next day at practice and qualifing, he was about 1 1/2 seconds slower a lap. Slower coming out of the corners.

If you are spinning the wheels then you need to moderate the throttle application and/or get a better differential. The extra accelleration coming out of the corners will always be worth it.

George E.

trackbird

iTrader: (4)

I see valid points to both sides of the arguement. How much power does the Cobra make? (is it stock, or 500hp) I'm only asking because a taller gear will help a stock vehicle much more than a very powerful one. If the car is traction limited with 3.42 gears (very traction limited), adding 3.73's will just make it worse. If, the driver is spinning the tires because he is exceeding the "friction circle" and hasn't pointed the car "somewhat straight" before standing on the power, that is a different problem. It will be decided by driver skill/style and the horspower and traction ability of the vehicle and tires.

Chris,

I guess that you may as well try them since they are already installed in the rear end. If you find that you are having major traction issues, I may consider taking some gear back out of the car. Just my thoughts....

Viper

iTrader: (6)

Chris

I'm in the same boat. And the more I think about it, the more I'm sticking with 3:42's. I've also had 2 friends who raod race drive my car and they suggested I stay with 3:42's. One of the guys has 3:73's in his 96' Camaro, and I love driving it, but I'm having trouble not spinning now with the 3:42's and Nitto RII's. One last thing, in autox, now that I have a 6600 shift point, 2nd gear is plenty with the 3:42's.