What does the M button really do in technical detail?

[GoingTooFast]

Originally Posted by sparoz

Dan reckons he's quicker with the M button off .

That's just because he can't handle the extra torque provided with the M button ON...

Now seriously, did anyone drag raced his 1M against the clock with the M button ON and OFF to see which mode is the fastest (DSC off)?

You really don't need to power-shift because at the time you take your foot off the gas pedal to shift you've passed the 4500rpm mark which means the WGs are already opened because you aren't at max. torque anymore and the turbos are already spooling very fast at this rpm, so when maximum acceleration is called for you immediately demand more than 80% of acceleration after shifting to engage the overboost function again with no spool up delay or lag even with the M button OFF.

[bdaddylo]

Originally Posted by GoingTooFast

That's just because he can't handle the extra torque provided with the M button ON...

Now seriously, did anyone drag raced his 1M against the clock with the M button ON and OFF to see which mode is the fastest (DSC off)?

You really don't need to power-shift because at the time you take your foot off the gas pedal to shift you've passed the 4500rpm mark which means the WGs are already opened because you aren't at max. torque anymore and the turbos are already spooling very fast at this rpm, so when maximum acceleration is called for you immediately demand more than 80% of acceleration after shifting to engage the overboost function again with no spool up delay or lag even with the M button OFF.

How is there extra torque with the M button on? It has all ready been documented by various members who have dynoed their 1Ms that there is no increase in HP or torque with the M button on or off. If you're drag racing from a standstill in M mode, the only advantage is the time it would take for the wastegate to close and the turbo to spool up in the non-M mode which is probably a tenth of a second. This topic needs to die.

[GoingTooFast]

Originally Posted by bdaddylo

It has all ready been documented by various members who have dynoed their 1Ms that there is no increase in HP or torque with the M button on or off.

Can you please give me the link to that?

Originally Posted by bdaddylo

If you're drag racing from a standstill in M mode, the only advantage is the time it would take for the wastegate to close and the turbo to spool up in the non-M mode which is probably a tenth of a second. This topic needs to die.

The car may be standstill but the engine is not... when you let go the clutch the engine should be between 1500-4500rpm with the gas pedal demanding more than 80% of acceleration. You can timing it with short burts of acceleration just before you let go the clutch. Vroom, vroom...

[clived]

Originally Posted by GoingTooFast

...when you let go the clutch the engine should be between 1500-4500rpm with the gas pedal demanding more than 80% of acceleration....

But it would not be under load...

[GoingTooFast]

Originally Posted by clived

But it would not be under load...

And what does it have to do with the WGs being closed or not?!

All that matters is the gas pedal position and the engine rpm, isn't it?!

Once you let go the clutch you will have all the torque available and you can see if its value is the same with the M button ON or OFF... from the clock!

[clived]

If you're in a car with a dump valve and you rev it whilst at the lights, do you hear the boost being dumped every time you lift off the throttle?

[GoingTooFast]

Originally Posted by clived

If you're in a car with a dump valve and you rev it whilst at the lights, do you hear the boost being dumped every time you lift off the throttle?

Please elaborate...