# SMG M3 Transmission: Operation in Sport Mode ?????



## Leo (Apr 23, 2003)

Just a note:

What does the "Sport Mode" have to do with SMG II?  

Doesn't "Sport Mode" also come with normal stick models?  

If so then I think "SMG" should be removed in the above post by "vatkens".

Thanks.

///Leo


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## TGray5 (Jan 22, 2002)

I believe Vatkens was trying to address the complaints from some new owners of SMG cars that the car jerks and bucks. For awhile it seems that a newbie would post this question almost weekly on many M3 boards.


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## Leo (Apr 23, 2003)

Thanks.

I still believe it's very misleading.

Jerkiness with SMG and Sport Button are 2 different things and have nothing in common.

Jerkiness using SMG arises when:

- Driver in unfamiliar using SMG
- Car is new and not broken-in yet
- Car doesn't have the latest SMG version

The transmission is the same on standard and SMG equipped M3's.

Sorry, I don't want to get emails having to explain what the poster meant thinking it's an SMG problem 

///Leo


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## TGray5 (Jan 22, 2002)

Leo said:


> *Thanks.
> 
> Jerkiness with SMG and Sport Button are 2 different things and have nothing in common.
> 
> ///Leo *


Of course SMG and sport button are totally different things, but they do have something in common...throttle control. It is much more difficult for a new owner of an SMG car to be smooth if he's in sport mode....even if he has the latest software. I haven't seen reports of new owners of 6 speeds having the problem, so it clearly is an SMG specific issue.


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## saksiri (Apr 16, 2003)

the jerkiness is easily induced on manual cars also...

i think the thing with manual is that you can depress the clutch pedal to stop any lurching/jerkyness that occurs, while this isn't an option with SMG (although taking your foot off the throttle completely or steadying it on the throttle will also stop it... or upshifting).


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## cchan (Sep 19, 2002)

Hope this does not confuse the original issue-

One thing that I have noticed with SMG in sport mode is that it does engage the clutch more quickly than in normal mode during rolling low speed starts. I have to drive over a bunch of speed bumps at the office in the parking lot. Usually I go over them ~5mph and pull away lazily to 10-15mph in 2nd gear rather than drop it down to 1st gear. Going over the speed bump at 5mph, SMG is in 2nd gear but the clutch is disengaged due to the low speed to prevent the engine from stalling. After going over the bump and slowly speeding up, in normal mode the SMG seems to feather and slip the clutch more before it is fully engaged (maybe ~1500 rpm), but in sport mode it slips less (seems fully engaged ~1100-1200rpm and more quickly). In the back of my mind, I'm thinking that normal mode is causing more clutch wear during these low speed starts... seems like unneccesary/undesirable clutch slip to me (but perhaps better than jerkyness).

This is the only situation I've found where the transmission seems to be doing something noticibly different in sport vs. normal mode. Of course, this could simply be caused by the faster throttle responsiveness; more aggressive throttle = faster clutch engagement?

I'm only at about 1600 miles, so I might not be completely broken in yet. Dealer said I had the most current software when I had the first service done.


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## Pinecone (Apr 3, 2002)

cchan said:


> *Hope this does not confuse the original issue-
> 
> One thing that I have noticed with SMG in sport mode is that it does engage the clutch more quickly than in normal mode during rolling low speed starts. I have to drive over a bunch of speed bumps at the office in the parking lot. Usually I go over them ~5mph and pull away lazily to 10-15mph in 2nd gear rather than drop it down to 1st gear. Going over the speed bump at 5mph, SMG is in 2nd gear but the clutch is disengaged due to the low speed to prevent the engine from stalling. After going over the bump and slowly speeding up, in normal mode the SMG seems to feather and slip the clutch more before it is fully engaged (maybe ~1500 rpm), but in sport mode it slips less (seems fully engaged ~1100-1200rpm and more quickly). In the back of my mind, I'm thinking that normal mode is causing more clutch wear during these low speed starts... seems like unneccesary/undesirable clutch slip to me (but perhaps better than jerkyness).
> 
> ...


As far as anyone outside BMW knows, there is NO change to SMG operation with Sport mode. The quicker throttle opening will give harder clutch engagement.


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## madplaye2 (Jul 3, 2003)

I have a question with SMG can you be in any gear at any speed, or does it not let you go into 6th gear at 45 mph or something like that? 
Just curious I have only has 6 speed experience


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## cchan (Sep 19, 2002)

madplaye2 said:


> I have a question with SMG can you be in any gear at any speed, or does it not let you go into 6th gear at 45 mph or something like that?
> Just curious I have only has 6 speed experience


Generally speaking, yes... with the exceptions that
- it won't downshift to a lower gear if it would wind up overreving the engine (downshift will be delayed until car speed drops enough)
- I've found that it won't allow an upshift if you are still under ~1500 rpm in the current gear
- it will automatically downshift two gears if you are slowing down and engine rpm falls to almost 1000rpm (such as coming to a stop). At least that's in S4 mode - other shift settings may be different, S4 is what I use most of the time.

so yes, you can get into 6th gear at around 40+ mph


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