[nismoman]

2017 6 spd

Any body else notice that when you up shift while at WOT, there is a difference in time from when the clutch is released to the power being delivered when in sport+ vs MDM vs DTC held off, with DTC completely off being an almost immediate 1:1 engagement. I am assuming this controlled by some sort of software since the drive mode dictates that difference. Is this tune-able?

[detroitm2]

Definitely noticed it. Unsure if its tunable. I'm certain its just a bit of code to help save transmissions during the warranty period.

[widetyres]

Yes definitely notice this.

A gfb dv+ might help a little bit but it won't get rid of it all as there is definitely some software in play.

I did think about hacking the clutch switch to get rid of it (I have done this in a porsche before) as the ecu doesn't know when the clutch is dis engaged, but have thought better of it as on a turbo car with an electronically controlled dv, that is just going to be asking for trouble.

[BruceM]

The dv+ does help on a 2017 6MT. More under boost in the mid-range on gear change than at WOT up top, but it is still a solid mod.

[nismoman]

I am not aware of the diverter valve mod but i will search to see what it is. Thanks! It def feels weird coming from the e46 m3 into this. It's honestly my only complaint if even that.

[David.m]

Shift between 6-7k rpm and power comes back immediately with wot. Shift under 6k and I experience the delay on wot. I find no lag though doing short shifts on 1/2 or 3/4 throttle, all this in Sport+

[MZWIE]

That is the way the DCT/ENGINE have been programmed. There is no way to fix it or tune it.

The GTS update for the DCT had high hopes but turned out to be incompatible with the tranny on the M2.

[F87source]

If it's software then eventually it will 100% be fixable through a tune. I heard an istep flash to the latest version helps but I can't really remember.

[chmura]

Doing some research and there is some kind of restriction device that needs to be drilled through in the clutch slave cylinder.

This is what is causing a 1-2 gear slow shift. You can read through the thread here. Later on he drills through the restriction valve and his no more delay.

https://f30.bimmerpost.com/forums/sh....php?t=1486773

it appears that the part numbers for clutch slave cylinder are the same between M2C, M2, F30 and:

Quote:
1' F20   (11/2011 — 02/2015)
1' F20 LCI   (06/2014 — 08/2018)
1' F21   (12/2011 — 02/2015)
1' F21 LCI   (07/2014 — 08/2018)
2' F22   (10/2012 — 06/2017)
2' F22 LCI   (09/2016 — 08/2018)
2' F87 M2   (11/2014 — 06/2017)
2' F87 M2 LCI   (09/2016 — 08/2018)
2' F23   (03/2014 — 06/2017)
2' F23 LCI   (10/2016 — 08/2018)
3' F30   (04/2011 — 07/2015)
3' F30 LCI   (10/2014 — 09/2018)
3' F80 M3   (04/2012 — 06/2015)
3' F80 M3 LCI   (01/2015 — 08/2018)
3' F31   (08/2011 — 06/2015)
3' F34 GT   (07/2012 — 06/2016)
4' F32   (11/2012 — 02/2017)
4' F32 LCI   (05/2016 — 08/2018)
4' F82 M4   (02/2013 — 02/2017)
4' F82 M4 LCI   (05/2016 — 08/2018)
4' F33   (03/2013 — 06/2016)
4' F83 M4   (06/2013 — 02/2017)
4' F83 M4 LCI   (05/2016 — 08/2018)
4' F36 Gran Coupé   (07/2013 — 06/2016)

[F87source]

Originally Posted by chmura

Doing some research and there is some kind of restriction device that needs to be drilled through in the clutch slave cylinder.

This is what is causing a 1-2 gear slow shift. You can read through the thread here. Later on he drills through the restriction valve and his no more delay.

https://f30.bimmerpost.com/forums/sh....php?t=1486773

it appears that the part numbers for clutch slave cylinder are the same between M2C, M2, F30 and:

Quote:
1' F20   (11/2011 — 02/2015)
1' F20 LCI   (06/2014 — 08/2018)
1' F21   (12/2011 — 02/2015)
1' F21 LCI   (07/2014 — 08/2018)
2' F22   (10/2012 — 06/2017)
2' F22 LCI   (09/2016 — 08/2018)
2' F87 M2   (11/2014 — 06/2017)
2' F87 M2 LCI   (09/2016 — 08/2018)
2' F23   (03/2014 — 06/2017)
2' F23 LCI   (10/2016 — 08/2018)
3' F30   (04/2011 — 07/2015)
3' F30 LCI   (10/2014 — 09/2018)
3' F80 M3   (04/2012 — 06/2015)
3' F80 M3 LCI   (01/2015 — 08/2018)
3' F31   (08/2011 — 06/2015)
3' F34 GT   (07/2012 — 06/2016)
4' F32   (11/2012 — 02/2017)
4' F32 LCI   (05/2016 — 08/2018)
4' F82 M4   (02/2013 — 02/2017)
4' F82 M4 LCI   (05/2016 — 08/2018)
4' F33   (03/2013 — 06/2016)
4' F83 M4   (06/2013 — 02/2017)
4' F83 M4 LCI   (05/2016 — 08/2018)
4' F36 Gran Coupé   (07/2013 — 06/2016)

Yeah it's the clutch delay valve, but from what I heard before it was really hard to replace since it was built in. I'm not sure how easy it is to drill through but so far I dont see any aftermarket support like on older cars where the restrictor was removable.

[XutvJet]

Do you feel it most on the 1-2 shift? If so, it may be the tires spinning and the traction control system neutering some power when in Sport+/MDM. It could also be the clutch delay valve intervention as F87Source noted.

The other issue is simply the fact that it's a turbo with a manual transmission. Although the DME uses some wizardy with the electronic waste gate and timing to maintain some boost on on full throttle shifts above 6,000rpms, you still loose a bit of boost between shifts, especially the 1-2 and/or if you're not fast on your shifts. This can create a lag or power on/off sensation.

If you're running a tune on a 6MT, the momentary lag on shift, especially the 1-2 and 2-3, can be pretty apparent. The lag gets really bad on my M235 when running the Dinan Sport tuner in Sport+ or Race mod. It's so bad that I turned the thing off because of the inconsistent power delivery, especially on the 2-3 shift. I could literally count to 1 before power kicked in fully on a completed, and quite hard, 2-3 shift.


Two mods that have have greatly reduced lag on shifts and improved response in my M235, which is very similar to the N55 in your M2, are:

1) Installation of the Ultimate Clutch Pedal. The UCP has greatly enhanced my ability to shift quickly in all situations. The pedal is firmer, catches much faster, and the resting position is lower as well.

2) HJS Euro 6 300 cell downpipe. The difference in throttle response and lag is immense, especially on full throttle shifts. I do not notice any perceivable lag on full throttle, 6,000rpm+ shifts. Even with no tune, the catted downpipe has increased power (especially in the mid range) and made the car far easier to drive, especially on 1st gear starts and the 1-2 shift.

It's remarkable the improvement in driveability these two mods have made.

[F87source]

Originally Posted by XutvJet

Do you feel it most on the 1-2 shift? If so, it may be the tires spinning and the traction control system neutering some power when in Sport+/MDM. It could also be the clutch delay valve intervention as F87Source noted.

The other issue is simply the fact that it's a turbo with a manual transmission. Although the DME uses some wizardy with the electronic waste gate and timing to maintain some boost on on full throttle shifts above 6,000rpms, you still loose a bit of boost between shifts, especially the 1-2 and/or if you're not fast on your shifts. This can create a lag or power on/off sensation.

If you're running a tune on a 6MT, the momentary lag on shift, especially the 1-2 and 2-3, can be pretty apparent. The lag gets really bad on my M235 when running the Dinan Sport tuner in Sport+ or Race mod. It's so bad that I turned the thing off because of the inconsistent power delivery, especially on the 2-3 shift. I could literally count to 1 before power kicked in fully on a completed, and quite hard, 2-3 shift.


Two mods that have have greatly reduced lag on shifts and improved response in my M235, which is very similar to the N55 in your M2, are:

1) Installation of the Ultimate Clutch Pedal. The UCP has greatly enhanced my ability to shift quickly in all situations. The pedal is firmer, catches much faster, and the resting position is lower as well.

2) HJS Euro 6 300 cell downpipe. The difference in throttle response and lag is immense, especially on full throttle shifts. I do not notice any perceivable lag on full throttle, 6,000rpm+ shifts. Even with no tune, the catted downpipe has increased power (especially in the mid range) and made the car far easier to drive, especially on 1st gear starts and the 1-2 shift.

It's remarkable the improvement in driveability these two mods have made.

Maybe disable all the electronic nanny's and try it then to see if the car cuts power idk. I notice the bog as well but that's when I shift sub 6000rpm like many of you have said, or when the car cuts power for traction control. But there are moments where it all works just fine, so it's really hard for me to pin the bog on one particular issue as well.

Maybe some tuners will eventually figure it out.

[switlikbob]

Interesting, thank you for this info. I find the clutch and manual transmission driving experience on the M2 to be very "digital". It's almost comical to me, and I feel as though the 6MT was an after thought with the M2. I do agree that there is always "boost lag" unless shifting is done above 6k rpm. I also notice the power pulling nannies quite a bit, but I hope to combat the with some super sticky rear tires. I really don't notice the CDV, like it was in the old days though...

[widetyres]

Originally Posted by switlikbob

Interesting, thank you for this info. I find the clutch and manual transmission driving experience on the M2 to be very "digital". It's almost comical to me, and I feel as though the 6MT was an after thought with the M2. I do agree that there is always "boost lag" unless shifting is done above 6k rpm. I also notice the power pulling nannies quite a bit, but I hope to combat the with some super sticky rear tires. I really don't notice the CDV, like it was in the old days though...

If you like the analogue experience, turn off dsc (like op mentions)

I did it this morning and left two massive black tramlines down the carriage way!!!

[widetyres]

Does anyone know if coding the m4 gts dsc affects this? That car is supposed to be a bit of a handful, so perhaps there are less digital nannies - I'll give this a go next week.

[nismoman]

Thanks for all the inputs and suggestions, the car is a manual and it does feel like the clutch delay valve on the stock e46 when in sport/sport+/comfort. It must be like some of you have suggested that some sort of electronic nanny is intervening because it doesn't matter what gear i'm in, it only feels like a normal mechanical old school clutch with traction control turned completely off. Very interesting indeed!

[switlikbob]

Originally Posted by widetyres

If you like the analogue experience, turn off dsc (like op mentions)

I did it this morning and left two massive black tramlines down the carriage way!!!

I daily drive an e46 ///M3. Now that's analog.

[M Fifty]

Originally Posted by nismoman

2017 6 spd

Any body else notice that when you up shift while at WOT, there is a difference in time from when the clutch is released to the power being delivered when in sport+ vs MDM vs DTC held off, with DTC completely off being an almost immediate 1:1 engagement. I am assuming this controlled by some sort of software since the drive mode dictates that difference. Is this tune-able?

There is a delay in the clutch engaging, but - based on how it changes with driving mode - it sounds like you're experiencing turbo lag.

Obvs. it 'could' be that you've been skipping Leg Day...

HTH...

[widetyres]

Originally Posted by M Fifty

There is a delay in the clutch engaging, but - based on how it changes with driving mode - it sounds like you're experiencing turbo lag.

Obvs. it 'could' be that you've been skipping Leg Day...

HTH...

Nope, it's not just turbo lag, it's the dsc reigning back the throttle. Spend some time in sport+ and then go back to sport and it feels very delayed in putting the power down in comparison.

Then as op says, with dsc off the car becomes very responsive with very little noticeable lag.

I really like how the no dsc feels for power delivery, but I would prefer to retain some traction control - I'll investigate coding options on the dsc.