DansBlkonBlkZ06

I tore up my MN12 at VIR and am getting an MN6 put in. Has anyone also switched the rear end to the C5 3.15? I'm hearing the 3.15 will run better with the MN6 than the 3.42 that I have. I don't want to use 5th gear for time trials.

redtopz

4th gear is the same with either one, 1:1. 1-3 gears are taller with the MN6 so I wouldn't put a taller rear gear in.

J.R.

https://www.corvetteforum.com/forums...ies/iagree.gif

I agree with Bill, you will not be happy putting in 3:15, and using Corvette power band on most tracks. 3:42 will work adequately on most tracks.

SouthernSon

I opted for the 6 when I rebuilt my original 12 using same z rear end. I didn't like the 6 so went back to the original 12. It works better for the big camshaft and tracks that I frequent. These changes really can be track specific.

Bill Dearborn

The 6 has a better spread between gears and is used on the C6Z. On a road course you use 3rd and 4th gears most of the time with either transmission but the 6 works better since you can run in 3rd at speeds up to 110 with an LS1. The LS6 limiter hits at 6500 so you can get another 300 rpm before hitting the limiter. That means you can approach speeds closer to 115 in 3rd. This helps on straights where you run into the rev limiter with the 12 and have to shift to 4th or carry the car on the limiter for a couple hundred more feet before braking and downshifting. That way you avoid an upshift and downshift within a second or two of each other which means less chance of an error. Sure the 12 will give you an extra boost in acceleration off the turn but that may or may not offset the slower acceleration you get by being forced to shift to 4th.

It all depends on the track you are running. Shorter tracks with short straights the 12 would be better but on longer tracks with long straights the 6 is probably better.

Bill