Double clutch question

[mhb]

hello
does anyone know if in a double clutch box system , the clutches are both disengaged when stopped in traffic and foot on brake
thanks

 

[grober]

Almost certainly both clutches would have to be disengaged. Only possible because the gearbox control unit would be constantly receiving road speed signals from the wheels and demand {or lack of it} signals from throttle and brake pedals . Presumably below a certain road speed and with certain throttle/ brake pedal position both clutches would automatically disengage and after a short predetermined period at rest engage neutral also ??

 

[Deleted member 126251]

I know this is not an answer to your question but may be related.......I've read a lot of information about double clutch systems not lasting when the car is used as a commuter (i.e. sitting in traffic) - not sure if the newer systems have resolved this issue..

 

[grober]

I am going to revise the above statement in the light of info from the VW dual clutch setup where evidently a degree of clutch slippage is built in when halted to prevent any car from slipping back on a hill in the event of the brake pedal being released. You could test this for your own setup by coming to a halt on a slight slope, leaving the car in drive and releasing the footbrake?

 

[John]

I'm pretty sure my dad's Seat Altea DSG does not slip backwards on a slight incline.

Dry clutch-based gearboxes will always wear out quicker in stop/start traffic. Best bet is for a slushy or CVT in such a situation.

 

[Red C220]

The DSG in our Audi rolls and the car has Hill Hold assist (the same as the brake hold function on an MB) to counter this. How far it rolls I'm not sure as I've never tried to find out.

With Hill Hold assist engaged the car engages one of the forward gears and accelerates without pause once you hit the throttle.

I assume it would disengage both clutch packs when Neutral is selected but in either D or R it's likely to have a gear ready to go.

Now owning both a DSG and Torque converter autos I would pick something with a torque converter for driving in town/commuting in stop start traffic. Preferably with a ZF 8 Speed.

On the open road the gear changes of a DSG are almost imperceptible (with a large capacity engine) and incredibly fast. Around town, stop/start can be clunky and you have to "learn" how to drive it in these situations.

 

[mhb]

thanks for he info,its very helpful,Ive just converted from a traditional torque converter auto box,to a double clutch system, and wondering what the driving technique should be,
and how to hold it on a hill,

 

[Red C220]

thanks for he info,its very helpful,Ive just converted from a traditional torque converter auto box,to a double clutch system, and wondering what the driving technique should be,
and how to hold it on a hill,

I find I let the DSG car roll more, give it a little more time between hitting the gas and lifting off the brake (unless the hold function is active at which point a gear is preselected) coming on and off the power sharply can "confuse" the twin clutch systems as they're not quite sure if you pulling up to a stop or about to hit the gas again.

I also change the driving mode to everything "comfort" most of the time. but play around with these settings as they can effect the response of the gearbox considerably. In the Audi I can configure these individually, so I could have the whole car in comfort mode bar the gear changes which can be set to dynamic and make them far faster.

So it's a case of playing around with the settings and figuring out what works. Of course my experience is based on an Audi S-Tronic.

 

[mhb]

I find I let the DSG car roll more, give it a little more time between hitting the gas and lifting off the brake (unless the hold function is active at which point a gear is preselected) coming on and off the power sharply can "confuse" the twin clutch systems as they're not quite sure if you pulling up to a stop or about to hit the gas again.

I also change the driving mode to everything "comfort" most of the time. but play around with these settings as they can effect the response of the gearbox considerably. In the Audi I can configure these individually, so I could have the whole car in comfort mode bar the gear changes which can be set to dynamic and make them far faster.

So it's a case of playing around with the settings and figuring out what works. Of course my experience is based on an Audi S-Tronic.

thanks thats great info

 

[Deleted member 126251]

I find I let the DSG car roll more, give it a little more time between hitting the gas and lifting off the brake (unless the hold function is active at which point a gear is preselected) coming on and off the power sharply can "confuse" the twin clutch systems as they're not quite sure if you pulling up to a stop or about to hit the gas again.

I also change the driving mode to everything "comfort" most of the time. but play around with these settings as they can effect the response of the gearbox considerably. In the Audi I can configure these individually, so I could have the whole car in comfort mode bar the gear changes which can be set to dynamic and make them far faster.

So it's a case of playing around with the settings and figuring out what works. Of course my experience is based on an Audi S-Tronic.

I have not driven a DSG equipped car, but the new 9 speed box in the MB is fantastic compared to the 7 speed I previously had..