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So the reason I asked this question is because I changed two parameters in my V12 107 at the same time. Not a good thing to do but the diff was ready to go. I had a 2.65 open diff and it just caused massive single wheel spin with the M120 V12. I replaced that diff with the stock 107 2.47 LSD diff. Now the car is slightly slower with no wheel spin at all. Best 60' time went from 2.04 to 2.14.
So apparently the significant increase in traction was more than offset by the 7% change in gearing. I think there is more to this than just the 7% reduction in torque. Especially noting that the same stock 107 560SL did 60' in 2.24 seconds.
I believe what is happening is the M120 and M117 have nearly the same torque at low stall speed 1500RPM launches. At least nearly so to make the the M120 have only a slight advantage over the M117 in 60'. Also the 722.4 trans has a slightly lower 1st gear ratio than the 722.6. If that is the case than the 7% change in gear ratio will have a significant effect on the acceleration as in not just a 7% reduction in torque but a further reduction from engine being out of the power band. In other words not only did I loose 7% of my torque at the starting line but I also effectively decreased my stall speed in a way.
This will all be answered when I install the 2.82 LSD. 2.82 will be kind of an optimal gear ratio because it will allow me to run out 3rd gear in the 1/4 mile.
So I guess I will be the one to answer this question but it will be a while.
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