I'm always wishing guys would give more feedback on their upgrades so thought I'd throw mine in here.

I have an M6 02 SS with about 415 rwhp. Seldom do I go to the dragstrip, but I do road race the car and about 5-6K miles a year on the street.

I needed more umph out of the corners and picked up some 3.73 oem gears cheap so I gave them a try. As I suspected, 3.90's would be a better choice for the track but the info on them being noisy quelled that idea.

The 3.73 gears have no noticeable whine or noise. They do make a noticeable improvement in acceleration, though I can't verify yet any change in mpg.

For what I use the car for the $500 spent, I think I got very close to my $ worth. Again-3.90's would have fit my goals better, but having no gear whine was at the top of my list (or very close) so it seems to be a good choice for the street and improving zip out of the corners.

I did get to the drag track just for giggles and only went down the qtr 3 times as it just would not hook on the crummy nitto 555r's. Even spun the car sideways a touch going into 4th. Lousy times at 13.3 and at 109+mph it should be running low 12's, but the lack of hook keeps the puny 10 bolt from blowing all over the track, so I guess we'll stay with the road course where we belong. Thx!

 

Thanks for posting, I've got a spare rear with motive 3.73s already set up. It needs axle bearings, but I'll end up having less than $75 with a fluid change. Its good to hear some real world experience. I'd probably go 4.10s or more, but since they're already set up its not worth the extra trouble.

 

I think if they made a quiet 3.90 set, they'd be the overall ticket for the M6 setup. (Not counting the 10 bolt going boom)

 

The bad news is that on the road it looks like I've given up over 1mpg. My truck may have to park and this become my DD. When it tops $5 a gallon, I may wish I had held onto the 3.42's or looking for those 3.23's for sale I see.

 

How is it that one gear ratio whines and another does not?