Optimal Shift Points

[bgreen4544]

Has anyone figured out what the optimal shift points are for an F82 with DCT? I'm using sport+/sport/sport/s3.
This is my first M car, just got it back from the 1200 service. When in "D" it seems to go all the way to redline in the first few gears but I'm thinking that might not be optimal to get the quickest times.

[parky1215]

If I remember corrctly, optimal shift point for first two gears is redline and around 7100 for remaining gears.

[Maddict3]

Originally Posted by bgreen4544

Has anyone figured out what the optimal shift points are for an F82 with DCT? I'm using sport+/sport/sport/s3.
This is my first M car, just got it back from the 1200 service. When in "D" it seems to go all the way to redline in the first few gears but I'm thinking that might not be optimal to get the quickest times.

+1

[CanAutM3]

To maximize acceleration, you want to produce as much average power as possible. In the case of the S55, it means keeping the revs above 5500rpm as much as possible. In the first two gears, this means redline shifts. For the other gears, it varies slightly between the DCT and 6MT. As long as the revs are above 5500rpm in the next gear, you should be fine. There is also no point of shifting above 7300rpm in third gear and above since the power tapers off at that point.

This is assuming that the power graph cartoon provided in the BMW press material is accurate when showing a power plateau from 5500 to 7300rpm. The better (more reliable) dyno runs seem to indicate that power continues to increase a little past 5500rpm. For those reasons I shift at 7300rpm in 3rd gear and above when I want max acceleration.

[bgreen4544]

Originally Posted by CanAutM3

To maximize acceleration, you want to produce as much average power as possible. In the case of the S55, it means keeping the revs above 5500rpm as much as possible. In the first two gears, this means redline shifts. For the other gears, it varies slightly between the DCT and 6MT. As long as the revs are above 5500rpm in the next gear, you should be fine. There is also no point of shifting above 7300rpm in third gear and above since the power tapers off at that point.

This is assuming that the power graph cartoon provided in the BMW press material is accurate when showing a power plateau from 5500 to 7300rpm. The better (more reliable) dyno runs seem to indicate that power continues to increase a little past 5500rpm. For those reasons I shift at 7300rpm in 3rd gear and above when I want max acceleration.

Thx

[shortseller]

Shifting from 1st to 2nd at 7300 RPMs is going to scare the crap out of somebody in front of you!

[dmnc02]

Originally Posted by CanAutM3

To maximize acceleration, you want to produce as much average power as possible. In the case of the S55, it means keeping the revs above 5500rpm as much as possible. In the first two gears, this means redline shifts. For the other gears, it varies slightly between the DCT and 6MT. As long as the revs are above 5500rpm in the next gear, you should be fine. There is also no point of shifting above 7300rpm in third gear and above since the power tapers off at that point.

This makes perfect sense. However, in a couple of YouTube videos I watched showing Launch Control in action (I have 6MT on my car, so no LC), the computer shifts to II between 6,000 and 6,500rpm (there seems to be a bit of variation across the two videos), to III at redline and to IV and V around 7,000rpm. The shift to II seems way too early based on the logic in the above post. Does anybody have a reason for the "early" shift? Traction consideration?

These are the two videos:

https://www.youtube.com/watch?v=LDs_WW6BGMo
https://www.youtube.com/watch?v=OzVfLD9zpTw

[CanAutM3]

Originally Posted by dmnc02

This makes perfect sense. However, in a couple of YouTube videos I watched showing Launch Control in action (I have 6MT on my car, so no LC), the computer shifts to II between 6,000 and 6,500rpm (there seems to be a bit of variation across the two videos), to III at redline and to IV and V around 7,000rpm. The shift to II seems way too early based on the logic in the above post. Does anybody have a reason for the "early" shift? Traction consideration?

These are the two videos:

https://www.youtube.com/watch?v=LDs_WW6BGMo
https://www.youtube.com/watch?v=OzVfLD9zpTw

I would say traction is what causes the early shift. There are other videos that show redline 1-2 shifts with launch control.

[dmnc02]

Originally Posted by CanAutM3

I would say traction is what causes the early shift. There are other videos that show redline 1-2 shifts with launch control.

So even with DSC completely off, LC takes traction into account in deciding when to shift?

[SakhirM4]

Originally Posted by bgreen4544

Has anyone figured out what the optimal shift points are for an F82 with DCT? I'm using sport+/sport/sport/s3.
This is my first M car, just got it back from the 1200 service. When in "D" it seems to go all the way to redline in the first few gears but I'm thinking that might not be optimal to get the quickest times.

I thought that the purpose of the DCT was that you didn't have to figure out those types of things - the car does it for you

[AM4ZING]

Originally Posted by SakhirM4

I thought that the purpose of the DCT was that you didn't have to figure out those types of things - the car does it for you

Right? Its automatic for a reason

[dmnc02]

Originally Posted by CanAutM3

I would say traction is what causes the early shift. There are other videos that show redline 1-2 shifts with launch control.

OK, I found a video showing LC shifting to II at redline. So the shift points are indeed adjusted dynamically. The system is smarter than I initially thought.

[Kankles]

Originally Posted by shortseller

Shifting from 1st to 2nd at 7300 RPMs is going to scare the crap out of somebody in front of you!

If they're in front of you they won't be for very long...you'll be up their ass pipe

[Bluex]

Originally Posted by SakhirM4

I thought that the purpose of the DCT was that you didn't have to figure out those types of things - the car does it for you

I'm fairly certain the car hasn't managed to figure out how to shift for you in sequential mode yet. It may be "automatic", but not to that degree

[mkoesel]

Originally Posted by SakhirM4

I thought that the purpose of the DCT was that you didn't have to figure out those types of things - the car does it for you

The main reason for DCT is quick shifts - the automatic mode is really more of a convenience feature. In D3 mode, yes, it probably does a pretty good job at shifting for optimal acceleration (though I can't say for sure because I never use the automatic settings). But by using the S modes you can short shift one minute, and hold gears to redline the next. You could switch to D1 or D2 to lower shift points too, but it's not as fun. If we can trust the pole on this forum, most DCT drivers shift manually at least some of the time. So knowing when to shift the DCT is still important for many people.

[SakhirM4]

Originally Posted by mkoesel

The main reason for DCT is quick shifts - the automatic mode is really more of a convenience feature. In D3 mode, yes, it probably does a pretty good job at shifting for optimal acceleration (though I can't say for sure because I never use the automatic settings). But by using the S modes you can short shift one minute, and hold gears to redline the next. You could switch to D1 or D2 to lower shift points too, but it's not as fun. If we can trust the pole on this forum, most DCT drivers shift manually at least some of the time. So knowing when to shift the DCT is still important for many people.

I stand corrected.