New to DSG

[eccleshill]

Try it in drive and you will probably explode the clutch!

Surely not!

The only difference between D & S is the engine revs at which the DSG changes gear. Sitting with the engine at the maximum allowed by the ECU (2000rpm?)with the brake on means that the drive plate(s) of the disengaged 1st gear clutch is rotating at the same 2000 rpm and the driven plate(s) is stationary. Releasing the brake engages the clutch; the spinning plate(s) hits the stationary plate(s) and they reach the same speed - the engine & drive plate slow with the sudden load and the driven plate comes up to speed. Whilst this is happening the clutch will slip and/or the wheels will spin depending on which is the line of least resistance.

All this happens in 1st gear whether in D or S and the inertia of the car is the same so the energy shock to the clutch at the point you release the brake and the plates collide is no different. In S you will accelerate harder once under way because the DSG red lines in every gear.

[jrw]

Surely not!

The only difference between D & S is the engine revs at which the DSG changes gear. Sitting with the engine at the maximum allowed by the ECU (2000rpm?)with the brake on means that the drive plate(s) of the disengaged 1st gear clutch is rotating at the same 2000 rpm and the driven plate(s) is stationary. Releasing the brake engages the clutch; the spinning plate(s) hits the stationary plate(s) and they reach the same speed - the engine & drive plate slow with the sudden load and the driven plate comes up to speed. Whilst this is happening the clutch will slip and/or the wheels will spin depending on which is the line of least resistance.

All this happens in 1st gear whether in D or S and the inertia of the car is the same so the energy shock to the clutch at the point you release the brake and the plates collide is no different. In S you will accelerate harder once under way because the DSG red lines in every gear.

Nothing to do with D or S - this is a launch control feature If it wasn't a feature then the ECU wouldn't restrict the revs. There is plenty of info on google about it and it seems that not all Diesels were blessed with it. You can't accelerate with the brake pressed in D or S in normal conditions (ie traction on) as the car will try and pull away.

http://en.wikipedia.org/wiki/Launch_control_(automotive)

Also here is a vid explaing the procedure (3k revs as its a petrol)

[Wardy]

WOW! What a thread

Personally when using a DSG/auto transmission I use neutral and the handbrake when stopping at a set of lights for any decent length of time. 30 secs plus perhaps? It's a good point on the DSG system about not being able to return to drive without the footbrake - but I find as the lights are about to go from red to green (perhaps watching the other set across a 4-way junction for a clue) I'll lightly press the footbrake, take off the handbrake, into Drive, off the brake and onto the gas and away we go. Perfectly achievable in seconds and certainly not going to hold up anyone behind me. And a few seconds of the brake lights in total, than perhaps 2-3 minutes otherwise? And you're not sat with your brake pads clamped to the discs either. I know which option I'll go with. I won't tell others what they should be doing though

IAM also teaches 'handbrake and neutral' as best practice in these situations, in case that helps anyone who has an aversion to the HC :p

Don't really see why this thread took the path it did. But remember people of Briskoda; if you really don't get along with another member, remember the Ignored Users option you have at your disposal. Just a thought....

Cheers,

Steve

[eccleshill]

Nothing to do with D or S - this is a launch control feature If it wasn't a feature then the ECU wouldn't restrict the revs.

I'm still not convinced - did a test tonight. With the gearbox in various states of disengaged and ESP on I gently squeezed the throttle gradually increasing engine revs to see how high it would go:

P (handbrake on) - maximum 3900 rpm

R left foot firmly on footbrake - maximum 3900 rpm

N (handbrake on) - maximum 3900 rpm

D left foot firmly on footbrake - maximum 3900 rpm

S left foot firmly on footbrake - maximum 3900 rpm

Tiptronic 1st gear selected - left foot firmly on footbrake - maximum 3900 rpm

repeated with ESP off - no difference.

The engine RPM wavered slightly around 3900 as the ECU simply went into safety mode to prevent over-revving when there is no load. So is this really an intentional launch control or just a neat way of making use of the over-rev prevention to get on full throttle the instant the engine is put under load.

Edited 22 February, 2011 by eccleshill

[m0bov]

Don't forget the ECU logs each launch and should you make a warranty claim I wonder if they check this?

[jrw]

I'm still not convinced - did a test tonight. With the gearbox in various states of disengaged and ESP on I gently squeezed the throttle gradually increasing engine revs to see how high it would go:

P (handbrake on) - maximum 3900 rpm

R left foot firmly on footbrake - maximum 3900 rpm

N (handbrake on) - maximum 3900 rpm

D left foot firmly on footbrake - maximum 3900 rpm

S left foot firmly on footbrake - maximum 3900 rpm

Tiptronic 1st gear selected - left foot firmly on footbrake - maximum 3900 rpm

repeated with ESP off - no difference.

The engine RPM wavered slightly around 3900 as the ECU simply went into safety mode to prevent over-revving when there is no load. So is this really an intentional launch control or just a neat way of making use of the over-rev prevention to get on full throttle the instant the engine is put under load.

Doesn't look like you have it then tbh.

[eccleshill]

Doesn't look like you have it then tbh.

I think I can learn to live with that