Performance Rear Axle 2:73

[Cosworth1]

Can anyone recommend an upgrade for my 2:73 "performance" rear axle gears in my '08 C6 ? Looking to find some gears around 3:73 or so ...and if GM makes them or aftermarket ? ;help thks

 

[glennkrick]

gears

Can anyone recommend an upgrade for my 2:73 "performance" rear axle gears in my '08 C6 ? Looking to find some gears around 3:73 or so ...and if GM makes them or aftermarket ? ;help thks

I replaced the 3.15 rear end in my 2000 Z51 with a factory 3.42 from the six speed stick it ran 13.00 quarters and still gets 27 mpg.
I have a 2009 Z51 orderd and plan to replace the 2.73 with the 3.15 that I have left from my 2000.
You buy and replace the hole differential not just the gears that way you have no problems with gear whine or reliability.
I would recomend the 3.42 over anything deeper you will have traction problems as it is with the 3.42.
Glenn 612 964 6777 cell
glennkrick@gmail.com

 

[NORTY]

I was going to recommend 3.42:1 from the Z06 model also.

During 2006MY production, GM experimented with 3.63:1 ratios on 8 Z06 powertrain mules. They chose 3.42:1 for the production models, as you know.

 

[Tuna]

With the A6 automatic and 3:73 gears, you'll find that first gear is pretty worthless and you'll toast the tires. You'll also lose a lot of gas mileage.

What are you looking to gain out of a gear change?
Are you looking for 1/8 drag performance? Street performance? Autocross performance?

 

[Hib Halverson]

With the A6 automatic and 3:73 gears, you'll find that first gear is pretty worthless and you'll toast the tires. You'll also lose a lot of gas mileage.

What are you looking to gain out of a gear change?
Are you looking for 1/8 drag performance? Street performance? Autocross performance?

Tuna is correct. Going from 2.73 to 3.73 with the six-speed auto will be a waste of money...unless you're going to put really sticky tires or drag slicks on the back and you're willing to take a big gas mileage hit.

 

[8850]

If you plan to drag race then keep the 2.73 and get a loose converter. With a properly sized converter you will be faster than any gear ratio.

I would recommend a PI 3600 as a compromise for street/strip. That's what I had in my 98 Camaro. Was worth .7 seconds improvement. A gear will get you about .3-.4 improvement.