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Discussion Starter · #1 · (Edited)
Re: SMG Shift speeds

The recent articles about the F430 really made me think about some of the information provided by BMW about SMG, and makes me wonder if it really shifts as fast as they say it does, and if it is really that much faster than a human.

We all know that BMW has said that the SMG3 trans upshifts in 65 milliseconds. And it has been said on the forum here that a human cannot shift faster than 500 milliseconds. That sounds a bit high to me, but lets go with it. If the M5 can shift so fast, why do all of the in car videos of acceleration runs lead me to feel that the upshifts are very slow.. like slower than I shift?

The recent Motor Trend comparo between the F430 and Ford GT1 had some interesting shift speeds listed. From memory (and I'll look at the article tonight to verify), they listed the measured shift speed for the F430 low to mid 20 milliseconds. And then they listed the GT's shift speed as only slightly higher.. like upper 20s or low 30s. and it is a traditional manual. Sorry, I don't have the mag in front of me to provide the actual shift speeds measured. But in any case... it left me wondering the truth of "what a human can shift" and "how fast SMG3 is".

Thoughts? If the measurements in Motor Trend are accurate on the GT.. makes me again want a manual in the M5.
 

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Re: Read SMG Shift speeds

The M5 will probably shift in around 65 milliseconds when using launch control thru the bit higher gears, 3 and up. A very well trained human can make a shift in around 0,3 seconds (300 milliseconds) compared to the 0,065 seconds the M5 can do it.
 

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Re: Read SMG Shift speeds

Dan --

I recall that the 430's F1-type transmission is reported to shift in 150 milliseconds. If so, this makes the SMGIII's performance truly impressive, and corroborates the relative impressions of the recently hotly-debated Autocar article.
 

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Re: Read SMG Shift speeds

check out this months Motor Trend story on the M6, they give SMG suprisingly high ratings for a US mag and speak about the shifts as wickedly fast...
 

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Re: Read SMG Shift speeds

MRichmond said:
Dan --

I recall that the 430's F1-type transmission is reported to shift in 150 milliseconds. If so, this makes the SMGIII's performance truly impressive, and corroborates the relative impressions of the recently hotly-debated Autocar article.
Its the same like the Ferrari ENZO. It does shift in 150 miliseconds (Suedkurier Newspaper)
 

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Re: Read SMG Shift speeds

Some time ago I read an article about new M5 and SMG shift speed was 65ms when the F1 gearbox shifts in 50 ms. So I doubt that any gearbox can shift faster than F1 and 20ms is impossible for me.
 

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Re: Read SMG Shift speeds

What exactly is the 65 ms referring to? Does it include the clutch/declutch time? Is it the time measured from the first movement of the lever/paddle? I think we need to know this before we start comparing to manual shift times.
 

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Re: Read SMG Shift speeds

Wolverine said:
What exactly is the 65 ms referring to? Does it include the clutch/declutch time? Is it the time measured from the first movement of the lever/paddle? I think we need to know this before we start comparing to manual shift times.
I believe BMW measures the time for the actual gear change and does not count the clutch in/out as part of the time. Ferrari counts both times in their numbers.

Still, SMG II/III are both faster than any human I know of :) If only I could get one for my other car to use at the track..
 

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Discussion Starter · #9 ·
Re: Read SMG Shift speeds

m630 said:
check out this months Motor Trend story on the M6, they give SMG suprisingly high ratings for a US mag and speak about the shifts as wickedly fast...
that is the mag I am thinking of. See the test comparo between the F430 and Ford GT? I think it is right before the M6 article. In any case.. the shift times between the two cars were really close.

And that doesn't explain why the shifts seem so slow in the videos...
 

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Re: Read SMG Shift speeds

My reaction to why SMG (2) feels slow is because when shifting a stick shift there are several things to occupy your brain to execute the shift. If we measure the time it takes from touching the clutch pedal, moving the shifter and then releasing the clutch, for most of us it probably takes about a second. But the whole time we are engaged. With an automated system all we have to do is pull a leaver or press a button and our brains are so powerful that even if the shift happens in 25% of the time of a stick shift, err... shift- it seems like its slow because we are left unoccupied in a situation in which we are normally occupied. As for watching on videos. Maybe SMG shifts are very clean and stick shifts are more blurred- giving the illusion of fast shifts. IMHO SMG2 shifted faster than I could nearly all the time- but it just wasnt as engaging for me to drive on public roads. I am hoping SMG3 changes my opinion.
 

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Re: Read SMG Shift speeds

MEnthusiast said:
My reaction to why SMG (2) feels slow is because when shifting a stick shift there are several things to occupy your brain to execute the shift. If we measure the time it takes from touching the clutch pedal, moving the shifter and then releasing the clutch, for most of us it probably takes about a second. But the whole time we are engaged. With an automated system all we have to do is pull a leaver or press a button and our brains are so powerful that even if the shift happens in 25% of the time of a stick shift, err... shift- it seems like its slow because we are left unoccupied in a situation in which we are normally occupied. As for watching on videos. Maybe SMG shifts are very clean and stick shifts are more blurred- giving the illusion of fast shifts. IMHO SMG2 shifted faster than I could nearly all the time- but it just wasnt as engaging for me to drive on public roads. I am hoping SMG3 changes my opinion.
Good points. Does anyone have the comparable "first move of the shifter to completion of gearchange" time for the smg III?
 

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Re: SMG Shift speeds

The only meaningful measure of the time is for the entire period where the engine is disengaged from the wheels - when the clutch is engaged to when it is let go.

Tom
 

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Re: SMG Shift speeds

bernhtp said:
The only meaningful measure of the time is for the entire period where the engine is disengaged from the wheels - when the clutch is engaged to when it is let go.

Tom
Correct, measuring shift time using any other way would be meaningless. It would be the entire period of clutch disengagement, gear change, and clutch reengagment -- how long it takes to go from 1st to 2nd, etc. Otherwise, one is not measuring the desired period of time trying to be measured.
 

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Re: SMG Shift speeds

One could argue that clutch pedal travel time should be taken into account but basically I agree. The corresponding time for the SMG would be from tap of the shift lever to completion of the shift, including clutch out.
 

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Re: SMG Shift speeds

Digi said:
Correct, measuring shift time using any other way would be meaningless. It would be the entire period of clutch disengagement, gear change, and clutch reengagment -- how long it takes to go from 1st to 2nd, etc. Otherwise, one is not measuring the desired period of time trying to be measured.
I agree also. This is why the BMW numbers are impressive but misleading. Still I think if we used the above measure SMG would come out ahead of any human driver using the clutch (i.e. not abusing the gearbox)
 

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Re: SMG Shift speeds

I find the SMG on the M5 slower the M3, and on a few occasions it has caught me out when I have tried to overtake in a hurry. I am only hoping it is related to the running in period, because if it isnt it is going back for a software update as its unacceptably slow.
 

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Re: SMG Shift speeds

MattUK said:
I find the SMG on the M5 slower the M3, and on a few occasions it has caught me out when I have tried to overtake in a hurry. I am only hoping it is related to the running in period, because if it isnt it is going back for a software update as its unacceptably slow.
There must be a serious problem with your M5!

The SMGIII is nowhere close to being slow. It´s just freaking fast shifting and so very enjoyable in every aspect.

I don´t understand why you all are making so much fuss about this increadibly good gearbox? Drive it and you will see!

I know after 12000 km in my M5.

SMGIII, SMGIII, SMGIII...........
 

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Re: SMG Shift speeds

Must agree with cidiar, when my dad was out driving Denmark's official demo car, he said.. Let me quote (translated): "I was driving in third on the highway and I barely touched the gear lever before the car was running in 4th gear. It was unbelieveable! It was very brutal but, wow, impressive."

This was done in mode S6 of course.
 

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Re: SMG Shift speeds

Try to have a look at the M5 "The Ring" trailer/movie or whatever it is, after watching that you are very assured that it has fast shifting times. I'm referring to one particular scene, there is a camera located on the front spoiler and you see this M5 blasting on a straightline. You can hear the loud engine AND the gearbox. It sounds like a Formula 1 car, it goes like wruuuuuuuuuuum *klonk* wruuuuuuuu-uuuum. And you can hear how fast it actually changes gear, and that is really impressive. A-must-view for any doubters :)
 
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