0-60 speeds; faster DCT manual or automatic mode?

[Kevin G]

Seems like a simple question, but which would be faster 0 to 60 acceleration on a DCT - manually shifting or automatic (fast mode)?

[saleen556]

Auto.

[mkoesel]

They should be identical as long as you are shifting at the proper RPM when in manual mode. Using similar Drivelogic settings in both cases may also be important, and obviously this assumes equivalent launch techniques as well.

Depending on circumstances, using Launch Control might give you best results, but even if so, you could still emulate that in manual mode. Remember, you'll only need to shift once - from first to second - to get to 60mph. That would be easy enough to get right manually even if you used LC to do the actual launch.

[F83]

Auto. Less role the driver plays the better. Soon they will have a "0-60 Button" and all you gotta do is press it. It's a trend I don't like at all but it is real.

[OutlawX3M]

Manually shifting the DCT vs letting the programming do it for you?

Logically speaking, for us to be faster manually shifting the DCT, the assumption would need to be that the programming isn't shifting at the optimal upshift point and we (humans) could do it.

I can't see M doing that. Then again, I could be wrong..... I'm assuming the shift points are programmed for "absolute speed" where there could be more variables involved (longevity/warranty, liability, etc).

Would be fun testing this if we had the proper equipment.....

[shortseller]

Originally Posted by mkoesel

They should be identical as long as you are shifting at the proper RPM when in manual mode. Using similar Drivelogic settings in both cases may also be important, and obviously this assumes equivalent launch techniques as well.

Depending on circumstances, using Launch Control might give you best results, but even if so, you could still emulate that in manual mode. Remember, you'll only need to shift once - from first to second - to get to 60mph. That would be easy enough to get right manually even if you used LC to do the actual launch.

0-60, Is this also true in sport vs sport+ engine management mode? Efficiency, must be slower based on my dyno butt?

[OutlawX3M]

Originally Posted by shortseller

0-60, Is this also true in sport vs sport+ engine management mode? Efficiency, must be slower based on my dyno butt?

This is a good article that explains some of the dynamics of the "modes".

"In the SPORT and SPORT PLUS modes, the waste gates remain closed under partial load and the mass flow is routed through the turbines, to ensure that the turbochargers are already rotating at a higher base speed even in standby. Moreover, certain special engine control functions are brought into play that accelerate activation of the turbochargers. This means that the car responds more closely to the accelerator in SPORT and SPORT PLUS modes.

Another important point is that we normally have to take the drive train into consideration when it comes to building up torque. As a rule, the engine is able to build up torque at a speed that is much faster than that with which the drive train can cope. You can imagine that the drive train then begins to behave like a torsion spring, which is first stretched out and then vibrates, resulting in juddering. To prevent such judders, it is necessary to dampen the engine’s build up of momentum to allow a harmonic progression of its response characteristics.

The rigid drive train of the new BMW M3 and BMW M4 is, however, optimised for a fast buildup of momentum, similar to a racing car, with a carbon fibre drive shaft, rear axle rigidly bolted to the body, suitably dimensioned drive shafts, etc. This means that the rigid drive train is also an important factor of the spontaneous entrance of the new BMW M3 and BMW M4. In EFFICIENT mode, everything is more levelled out, with a high orientation towards comfort. In stark contrast is the SPORT PLUS mode, which pays absolutely no attention to any comfort factors. In SPORT PLUS, all filter functions are deactivated and the engine responds directly to movements of the accelerator pedal – but this also requires someone behind the wheel who really knows what he is doing. In SPORT PLUS, everything is transmitted as sharply as a knife, in terms of what the engineering can do to facilitate fast lap times – whether in the engine, transmission, chassis or control systems."

[shortseller]

Thanks, that explains a lot behind the modes. I'm just curious if anyone has done 0-60 runs in each mode to see what the time differences are, if any? I've never seen this addressed by any of the review magazines. I'm guessing sport+ is faster in a 0-60 sprint than efficiency, but wondering if sport+ is faster than sport?

[mkoesel]

Originally Posted by shortseller

0-60, Is this also true in sport vs sport+ engine management mode? Efficiency, must be slower based on my dyno butt?

A bit OT, but yes, engine dynamics modes should also be normalized if for no other reason then it makes for a more controlled experiment.

That being said, if you compared two M3/M4, one set to D1/Efficient and the other set to S3/Sport+, my guess is that they would be very close in acceleration. I say this because at WOT and while shifting at high RPM, there is not going to be a whole lot of difference between the behavior of the engine and transmission.

Also, FWIW, theoretically, suspension settings will play a roll in launching as well.

[krotondo]

Originally Posted by Kevin G

Seems like a simple question, but which would be faster 0 to 60 acceleration on a DCT - manually shifting or automatic (fast mode)?

Side note...

Any pics of your car? I am ordering the same combo in december just will Full Leather (not sure if you have it)

[Kevin G]

Originally Posted by krotondo

Side note...

Any pics of your car? I am ordering the same combo in december just will Full Leather (not sure if you have it)

I don't have full leather; to me that's a bit much and more Maserati-like. But I love the car; such a different beast though from my E46 M!

[Kevin G]

And interior:

[shortseller]

Originally Posted by mkoesel

A bit OT, but yes, engine dynamics modes should also be normalized if for no other reason then it makes for a more controlled experiment.

That being said, if you compared two M3/M4, one set to D1/Efficient and the other set to S3/Sport+, my guess is that they would be very close in acceleration. I say this because at WOT and while shifting at high RPM, there is not going to be a whole lot of difference between the behavior of the engine and transmission.

Also, FWIW, theoretically, suspension settings will play a roll in launching as well.

Yes, and thank you. Just that I've yet to see this covered here on the forum, unless I missed it -even after a search, and to my knowledge never addressed in an article, so the 0-60 DCT shifting seemed more appropriate than starting a whole new thread that would get no participation.