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      09-15-2007, 12:01 AM   #32
rvacha
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Drives: '08 E92 M3
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Quote:
Originally Posted by swamp2 View Post
This can be estimated by estimating the number of on power upshifts during a lap. Then this number multiplied by about .2 s is a reasonable estimate of the time savings. There is probably about 50 on power upshifts in a typical 8 minute lap which equates to 10 seconds. Heck, even if my real "back of the envelope" estimate is off by a factor of 2 we are still looking at a full 5 seconds. The tires should be good for 5-10 s as well! So if we assume 8:05 with std. non cup tires and MT this rough estimate gets us to 7:55.

All of this is very speculative, yet also reasonable and perhaps even conservative. Under 8 minutes is still my bet for Cup+ tires and M-DCT!
I second your guess minus a few seconds. I think the M-DCT will be heavier, it is possible the diff has a different ratio, and limited grip of the rear tires may give up a little of the potential gain.
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