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Uvig3
04-02-2002, 01:34 PM
From Leo's site http://www.leo.nutz.de/

"Advanced engine electronics interrupt the engine’s tractive power for just milliseconds while the control unit changes the gears electro hydraulically, opening and closing the clutch, all without the clutch pedal."

This is also my personal experience with my new SMG M3. If you're shifting at low rev's, the interruption of power is more noticeable, even in S6. At high rev's, the shift is faster, but there is a noticable head jerk FORWARD during the shift (80 ms is significant).

This explains why 0-60 times are compromised slightly with the SMG. It does shift fast, but there's no way you can power shift and get a really good launch between gears. The best is a slight "chirp" from 1-2 and that's probably due to the power comming back on after the shift.

I'm not saying that the new SMG isn't a better choice than the manual. I am saying that there is a built in engine speed lowering when upshifting that affects acceleration performance. This effect is probably more than compensated by the quick and consistent shifts.

I'm still learning to appreciate it.

StMedina
04-02-2002, 01:39 PM
the SMG, then tell what you think about 0-60. Who cares about 0-60. I don't, I track the car, and nowhere on the track do you go from dead stop to 60.

mharpo
04-02-2002, 01:41 PM

'Jorg Muller'
04-02-2002, 01:57 PM
did a 0-60 when they waved one out, one would probably get black flagged. I HATE street-racers, I have politely waved at people who rev their engine trying to get me to race. I do my fast driving on deserted country roads or the track

StMedina
04-02-2002, 02:11 PM

Ray in seattle
04-02-2002, 02:42 PM

Ray in seattle
04-02-2002, 02:45 PM

Stuka
04-02-2002, 03:07 PM
Funny, that's where I discovered that if you get on the binders HARD in S6, the downshift is immediate. Of course, after several sessions of this, I was smelling the brakes...

Andy
02 M3 CB/Cloth SMG

StMedina
04-02-2002, 03:29 PM

Uvig3
04-02-2002, 04:04 PM
What was the rest of the info from Gtech, like hp, 1/4 mi time?

eatapc
04-02-2002, 04:18 PM
I haven't tried an all-out run in S6, and don't intend to until after 3500 miles, but I agree with your description of a very brief slow down (head jerk forward) at the 1-2 and 2-3 gear changes at high rpms under hard acceleration -- followed instantaneously by a more violent head head snap back.

I wondered at first if this was normal, but I figure that on a car without SMG, you'd normally get an even bigger lag during the de-clutch period. The action of stabbing the clutch and yanking on the shift lever is probably distracting enough that you don't notice the lag, and don't perceive it as unnatural.

Again, this gets back to what others have said repeatedly: A perfect launch and perfect speed shifts with a clutch might shave a tenth or two off the drag strip times, but why should I care? I didn't get an M3 to drag race it, and I want the clutch to last for awhile. The SMG 0-60 times will be consistently fast, and produce less wear and tear.

And then there's Ray in Seattle, who did 4.75, so maybe the SMG is just as fast anyway. No one has compared like with like yet: identical cars (including tires and options), identical weights (including drivers), equally good drivers (perhaps rotated), same gas, same time, same place, multiple runs. Then repeat with a different pair of cars to verify.

Ray in seattle
04-02-2002, 04:35 PM

Zapper
04-02-2002, 05:38 PM
I love your brakes...

oddlycalm
04-02-2002, 06:10 PM
If you want a car that you can power shift, get yourself a Detroit V8 with a Muncie rock crusher tranny and knock yourself out. Even it won't last all that long if it's abused regularly.

If you can't figure out why posting this kind of topic on an M3 forum makes you look out of touch with reality, an explanation probably won't help.

oc


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