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      06-04-2013, 10:29 PM   #83
flinchy
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Quote:
Originally Posted by swamp2 View Post
According to my work on the subject (I can post the force in gear vs. speed graphs if you like) the new F10 M5 should not be shifted at redline in all gears to obtain maximum acceleration. It is quite a fine line but IIRC in the M5 shifts into 5th through 7th should be at a bit before redline. As is the case with this simulation for the M4, the differences between shifting or not at redline in the M5 would be quite subtle, with only a very small bit to gain by shifting lower. I've seen the reports on m5board.com claiming that shifts are always at redline but I'm quite sure they are incorrect.

When to shift is quite simple, it is not about average power nor about torque, torque is irrelevant. One shifts where the accelerative force is higher in the next gear than if the shift was not made. In other words if lines on the force vs. speed in each gear cross that shift should be made at the vehicle speed (can back calculate rpm) where they cross. Simple.
found quickly through google, many more that all look the same

http://ecutuninggroup.com/files/2013...ning-Group.jpg

if you shift before redline there, you lose acceleration... well except like 6-7 since it's a super long gear to a slightly slightly longer gear, not enough of a difference.

same for any i can find on google

i used to use:
http://vlsicad.ucsd.edu/~sharma/Potpourri/perf_est.html

VERY good tool there... but it seems to be down now? sad... had to use http://glennmessersmith.com/shiftpt.html#data

but it IS about average power (multiplied out) therefore average torque man... what are you talking about?

ok, we're kinda saying the same thing though - yes it's about average power, which comes from torque, but if your actual at a certain RPM geared out is lower... you'll simply be putting less to the ground in the longer gear

it's not JUST about torque, it's EVERYTHING about torque, torque at the fly then multiplied through the gearbox, then the diff... if the next gear is a certain amount longer, AND the torque drop is too sharp, then yes you can shift early


ED: ah graphs above, and 7 speed, i was working off 6mt- every gear up to 5th was redline and even then it was only 100something off.

not sure on why you're getting 7080 in 4th and i'm not though, very strange

Last edited by flinchy; 06-04-2013 at 10:49 PM..