[widetyres]

Hi,

Due to M2 OG unfortunately being stolen, I am now considering getting an M2C.

Please can people with the M2C manual (MT) car let me know their experience with the post gearshift lag?

I have seen in this thread that a few people were reporting this issue in amongst a discussion about turbo lag:https://f87.bimmerpost.com/forums/sh....php?t=1812407
( MrOhnoez, SilverScotty , CSBM5 , Burnside81 I see that you all mention it, but thought it worth starting a new thread focused on this particular issue)

With the OG/N55 M2, the DME enforced post-shift lag was very frustrating, but fortunately, after loads of investigation by board members and evidencing, BM3 came to the rescue with a tune to dial it out for that engine.

Please can you let me know:

1) Is the post shift lag only noticeable in 1-2 shifts, or is it felt in all gears?

2) Roughly how long does the lag last before power comes back online?

3) Can you share a log that shows gearshifts?

4) Does anyone know if a tuner has fixed this for S55 engines?

Thanks loads!

[widetyres]

Re 4: I contacted ProTuningFreaks - they confirmed that the 6MT post shift lag fix they did before has also been rolled out to their S55 tunes! Happy days!

[chris719]

Originally Posted by widetyres

Re 4: I contacted ProTuningFreaks - they confirmed that the 6MT post shift lag fix they did before has also been rolled out to their S55 tunes! Happy days!

FWIW I am not sure if I notice this on the S55 or not. Sometimes I think I do but it's hard to tell. Is there an easy way to produce it?

[Track/S]

Originally Posted by chris719

FWIW I am not sure if I notice this on the S55 or not. Sometimes I think I do but it's hard to tell. Is there an easy way to produce it?

With CAE shifter i have noticed it only once, with oem shifter never.
S55 has no delay like N55.

[chris719]

Originally Posted by Prodrive_X

With CAE shifter i have noticed it only once, with oem shifter never.
S55 has no delay like N55.

Thanks. You can shift faster with CAE is the reason for that I assume?

[CSBM5]

It's torque management on a 1-2 upshift that I mentioned. Turn off DSC and quick-shift a 1-2 upshift at 7k in 1st (i.e. like you'd do at the strip)....max acceleration in 1st to 7k rpms, then lightening quick "throttle lift, slam clutch, snatch 1-2 upshift, clutch out, throttle pinned down". You'll feel a bog a split second since torque is managed. If not, it would of course blow away the tires like a car with this power output easily would (i.e. my E39 M5 would lay down 20 feet of 2nd gear rubber in similar upshift, and my E90 M3 will bark the tires loudly while also laying down rubber in 2nd). Normally one would have to carefully manage the throttle and clutch engagement rate going into 2nd gear on a car with this torque output and DSC off. As programmed, you can just go for it and not have to worry about it getting away from you in most cases.

It's not turbo lag...it's purposely programmed torque management, and it exists on the F8x M3/M4 6MT also.

That said, it apparently doesn't really affect maximum acceleration since C&D was able to get the 6MT M2C faster than the DCT version by 0.1 seconds. The 6MT is better able to be launched, hooked up hard, than the DCT as they said (at least by a competent driver with lots of launching experience...).

[chris719]

Originally Posted by CSBM5

It's torque management on a 1-2 upshift that I mentioned. Turn off DSC and quick-shift a 1-2 upshift at 7k in 1st (i.e. like you'd do at the strip)....max acceleration in 1st to 7k rpms, then lightening quick "throttle lift, slam clutch, snatch 1-2 upshift, clutch out, throttle pinned down". You'll feel a bog a split second since torque is managed. If not, it would of course blow away the tires like a car with this power output easily would (i.e. my E39 M5 would lay down 20 feet of 2nd gear rubber in similar upshift, and my E90 M3 will bark the tires loudly while also laying down rubber in 2nd). Normally one would have to carefully manage the throttle and clutch engagement rate going into 2nd gear on a car with this torque output and DSC off. As programmed, you can just go for it and not have to worry about it getting away from you in most cases.

It's not turbo lag...it's purposely programmed torque management, and it exists on the F8x M3/M4 6MT also.

That said, it apparently doesn't really affect maximum acceleration since C&D was able to get the 6MT M2C faster than the DCT version by 0.1 seconds. The 6MT is better able to be launched, hooked up hard, than the DCT as they said (at least by a competent driver with lots of launching experience...).

I have noticed this. My Z4M could chirp into 3rd occasionally once I removed the CDV.

[Track/S]

Originally Posted by chris719

Thanks. You can shift faster with CAE is the reason for that I assume?

Yes, for this reason with stock shifter i never witnessed delay, and i like to shift fast

[KevinC]

Originally Posted by chris719

I have noticed this. My Z4M could chirp into 3rd occasionally once I removed the CDV.

I removed the CDV on my Z4M back in the day and noticed literally zero difference. As for the M2c, I’ve never experienced this lag.

[chris719]

Originally Posted by KevinC

I removed the CDV on my Z4M back in the day and noticed literally zero difference. As for the M2c, I’ve never experienced this lag.

I noticed a very big difference, I also put it back in before I got rid of it so I got to experience it twice.

It's not magic like people say. It just does what it says, and that is slightly delay clutch engagement. Where it is noticeable is mostly modulating the clutch on takeoff from a stop, on a hill, or in reverse. The only other time I noticed it was the situation I mentioned, where with the CDV removed you get a more aggressive clutch dump on a shift.

I'm confident if you drove two back-to-back you would notice it, especially in car with as much clutch feedback as that one. Where I disagree with the crowd is where they claim it fixes all kinds of ills like the 1->2 shift. It did nothing for me there, I only appreciated it in traffic or launching the car.

I'm on the fence about doing the CDV on the M2C because I don't feel the delay as much as I did on the Z4M. I'd do it back and forth to test if it were still a separate little part and not part of the slave cylinder. It wasn't life changing but I preferred the car without it 100%.

[Enabled]

Originally Posted by KevinC

I removed the CDV on my Z4M back in the day and noticed literally zero difference. As for the M2c, I’ve never experienced this lag.

As far as the CDV in M2C, it made the clutch pedal a little softer to press. I do like the more direct clutch engagement, but I don't think it did much else overall. I wouldn't go back, however.

[widetyres]

Originally Posted by CSBM5

It's torque management on a 1-2 upshift that I mentioned. Turn off DSC and quick-shift a 1-2 upshift at 7k in 1st (i.e. like you'd do at the strip)....max acceleration in 1st to 7k rpms, then lightening quick "throttle lift, slam clutch, snatch 1-2 upshift, clutch out, throttle pinned down". You'll feel a bog a split second since torque is managed. If not, it would of course blow away the tires like a car with this power output easily would (i.e. my E39 M5 would lay down 20 feet of 2nd gear rubber in similar upshift, and my E90 M3 will bark the tires loudly while also laying down rubber in 2nd). Normally one would have to carefully manage the throttle and clutch engagement rate going into 2nd gear on a car with this torque output and DSC off. As programmed, you can just go for it and not have to worry about it getting away from you in most cases.

It's not turbo lag...it's purposely programmed torque management, and it exists on the F8x M3/M4 6MT also.

That said, it apparently doesn't really affect maximum acceleration since C&D was able to get the 6MT M2C faster than the DCT version by 0.1 seconds. The 6MT is better able to be launched, hooked up hard, than the DCT as they said (at least by a competent driver with lots of launching experience...).

Nice to hear that what management there is is only on 1-2 shifts. On N55 M2 it was on every shift.

[widetyres]

Originally Posted by Enabled

As far as the CDV in M2C, it made the clutch pedal a little softer to press. I do like the more direct clutch engagement, but I don't think it did much else overall. I wouldn't go back, however.

On my previous car, I was going to remove the CDV, but then BM3 tune sorted the lag iisue, so I left the CDV in, so that there was at least some torque management left in the system - I didn't want to create too much drive train shock given potential crankshaft issues.

Removal of the CDV apparent makes fast getaways from a standstill easier.

[widetyres]

Originally Posted by chris719

I noticed a very big difference, I also put it back in before I got rid of it so I got to experience it twice.

It's not magic like people say. It just does what it says, and that is slightly delay clutch engagement. Where it is noticeable is mostly modulating the clutch on takeoff from a stop, on a hill, or in reverse. The only other time I noticed it was the situation I mentioned, where with the CDV removed you get a more aggressive clutch dump on a shift.

I'm confident if you drove two back-to-back you would notice it, especially in car with as much clutch feedback as that one. Where I disagree with the crowd is where they claim it fixes all kinds of ills like the 1->2 shift. It did nothing for me there, I only appreciated it in traffic or launching the car.

I'm on the fence about doing the CDV on the M2C because I don't feel the delay as much as I did on the Z4M. I'd do it back and forth to test if it were still a separate little part and not part of the slave cylinder. It wasn't life changing but I preferred the car without it 100%.

I had an E90 Aplina D3 and removal of the CDV on that was clearly needed (from the feel of the clutch) and made a massive difference when I did get rid of it.
Agree, on F87 platform it seems less of a necessity to remove it, although it would be nice to try.

[pawelczyk7]

Originally Posted by widetyres

Hi,

Due to M2 OG unfortunately being stolen, I am now considering getting an M2C.

Please can people with the M2C manual (MT) car let me know their experience with the post gearshift lag?

I have seen in this thread that a few people were reporting this issue in amongst a discussion about turbo lag:https://f87.bimmerpost.com/forums/sh....php?t=1812407
( MrOhnoez, SilverScotty , CSBM5 , Burnside81 I see that you all mention it, but thought it worth starting a new thread focused on this particular issue)

With the OG/N55 M2, the DME enforced post-shift lag was very frustrating, but fortunately, after loads of investigation by board members and evidencing, BM3 came to the rescue with a tune to dial it out for that engine.

Please can you let me know:

1) Is the post shift lag only noticeable in 1-2 shifts, or is it felt in all gears?

2) Roughly how long does the lag last before power comes back online?

3) Can you share a log that shows gearshifts?

4) Does anyone know if a tuner has fixed this for S55 engines?

Thanks loads!

1st to 2nd is where it happens.... i found it can be avoided if you shift very very early from 1st to 2nd .. also having the clutch stop also helps a little at least IMO.

[chris719]

Originally Posted by pawelczyk7

1st to 2nd is where it happens.... i found it can be avoided if you shift very very early from 1st to 2nd .. also having the clutch stop also helps a little at least IMO.

I drove hard yesterday and noticed this "torque management" on 2nd to 3rd also. I did not have DSC off, however, but no light flashed. I'm not sure if we are talking about the same thing though exactly.

[MarlboroM2C]

21 6MT BSM M Drivers, no lag. No issues, very very happy.

[chris719]

Originally Posted by Enabled

As far as the CDV in M2C, it made the clutch pedal a little softer to press. I do like the more direct clutch engagement, but I don't think it did much else overall. I wouldn't go back, however.

Did you swap the slave cylinder with the E90 part or remove the restriction in the original? I wonder if the softer pedal is just due to the E90 slave?