Originally Posted by akh23456
Does a sc change things that much that dct gains 5-10 mph in trap speed.
First, you have the difference in shift speed. DCT makes 4 shifts at 0.03s each for a total of 0.12sec spent coasting. 6MT makes 3 shifts that would take a good driver 0.2s each for a total of 0.6s coasting. Total difference? 0.48s. That's like giving your competitor half a second head start. PG did a nice detailed write-up on this topic: http://www.m3forum.net/m3forum/showthread.php?t=361609
Unfortunately, that's just part of the equation. The other part is gearing where the DCT puts down more power everywhere in the 1/4 mile except for a small stretch between ~97 and ~112mph:
power vs speed, DCT vs 6MT (same engine/SC):
So a 6MT has to overcome not only a 1/2 second of coasting, but also putting down less power for 110 of the 125mph...
And since I made that graph, might as well make it relevant to the AA v ESS topic:
power vs speed, 6MT (AA vs ESS):
power vs speed, DCT (AA vs ESS):