jschindler

No, you want to keep it as close to peak horsepower as you can.

rayk

Well, Chevy's web site had close ratio in the write-up for the GS. 1-3 really are good for acceleration. There's a bigger drop going on the 3-4 shift, but it still really pulls. When you go into 5th, that's when the rate of acceleration seems to slow down.

I wonder if the speeds listed take into account the differences in wheel and tire diameter.

I wouldn't mind having the z06 ratio for 4th since 3rd and 4th are used a lot on my home course.

X25

The base car's rear tires' turning diameter is 26.9" vs. the wide body's rear tires' 26.7", so it's pretty much equivalent considering subtle diameter changes even from particular tire to tire and the impact of tire wear.

Except the 4th gear, ALL gear ratios for the MN6 are about 10% shorter so it will let you accelerate faster compared to a car with standard transmission when at the same gear. Both standard and even the closer ratio MN6 transmissions are very tall anyway, using the benefits of the broad torque curve our V8 engines provide. I don't think MN6 is designed or intended just for autocross. You benefit from it a lot at the road-course, too. When I attended track days with my C6 Z06, many times I had to take turns at the third gear as opposed to second, since second was a bit too short to finish up the turn, while third was too tall, thereby losing time. If the ratios were closer, I could better utilize the power of my engine. Obviously, it depends on the track as some mentioned, too.

Especially for the LS3 with much less torque available than the LS7, shorter ratios definitely help at most road-courses in my opinion, especially at those with slow/many turns. Would MN6 help LS7? Perhaps. Considering it already has 10+% more torque over LS3, perhaps the time gained at some corners would be lost back by having to change more gears during the whole lap, so it might be a toss-up or not much gain at all. But for LS3, I think it's a much needed help.

JoesC5

All Corvette manual transmissions have the same 4th gear ratio, no matter which version. It's 1:1

rayk

Thanks for the information and I really had a dumb moment there.

I know 4th is 1:1.

I meant is the GS tire diameter in the back greater then the stock C6 rear tire?

Maybe a taller third gear would be nice, but now I'll have to remember to watch it next time when at the track.

Anyways, the only time I really hit 5th is the straight at BIR. Need to get to some other tracks this year.

Shifter6

Some good info here.

Basicaly this comes down to gear spacing or rpm drop between upshifts. Now every track, road course, section of street etc. will have its own optimum gear spacing but what is the better all around gear set for the overall corvette driving experience? I am suggesting considering the wide tq curve/power band of LS2/LS3 engines the 1st 3 gears in the MNZ transmission are more optimal for overall acceleration.

When you look at the Z51 gearing; 1st is deeper than on the MN6. Then you redline and shift. Every time you do that for the 1st 3 gear changes the rpms drop to about 4500rpms, which happens to be just after peak torque.

When you look at the MN6, 1st is taller than on the Z51. There is a larger step to 2nd, dropping the rpms to about 4200. Then 2nd to 3rd is closer, dropping the rpms to about 4800. Then 3rd to 4th is even closer dropping the rpms to about 5000. I have read somewhere else the gear reduction is progressive to combat the increased air resistance at higher speeds. Whether this is necessary considering the low drag of a C6 and the very broad powerband of a LSX engine is the question.