Bins

http://www.autocarmagazine.com/news_...p?na_id=207216

brianh

... excuse my ignorance but what's a "double clutch"?

brianh

Baron009

Nice read. 911 S hmmm.... mmmmwuhahaha.

Sort a few things I didn't really want to hear is it's going up in weight (although not much) and it's going up in price too.

Kerry

Yes! They are using their own DSG!

kauai_diver

I second the motion, whats a double clutch?

wmy

DSG is a VW developed system where there are 2 clutches - one which is engaged as normal and the other is used to preselect the next gear. The new Audi TT's have this and you apparently get much quicker smoother shifts than other semi auto systems.

Carlos from Spain

The double-clutch squential tranny was originally developed by Porsche for their 80's 956/962 race cars and it was called "PDK", then later Audi used it also in racing. Now VW developed it for street cars and is calle DSG.

The double clutch as the name says, has two clutches, one for the 1st 3rd and 5th gears and the other for the 2nd 4th and 6th gears. While you are in one gear, the cluth for the folowing gear is engaged so when you shift to that gear the two clutches operate simulatneously to clucth one gear and engage the next one at the same time, therefore there is no interuption of power while in b/w gears and shifts are faster too (10 times faster than the fastest available sequential, the SMG-II). There is a computer that recognises if your next move will be a downshif or upshift to properly clutch the right gear before the shift.

As far as pros and cons with respect to the torque converter automatic and manual:

- The DSG is equal in weight as the manual unlike torque converter automatics which is heavier.
- The DSG (like the manual) during the shift robs no torque from the car unlike the torque converter automatics.
- The DSG shifts faster than a manual and automatically would do rev matching on downshifts.
- The DSG shift with barely any interruption in the power delivery through the gears hence can actually sometimes achieveve faster acceleration times than the manual.
- The DSG and the manual will have both 6 gears.

And the common to all auto-trans:
- The DSG allows to focus almost all the drivers concention solely on the steering/accel/braking and not having to worry about manually shifting which improves further the lap times and the driver is more effective and faster, especially the non-pro drivers..
- The DSG has no clutch pedal therefore you loose the driver involvement and pleasure (for some) of manually shifting, rev matching, etc.

I'm still not convinced all the benefits are worth while loosing the involvement of the manual, and I would stay away from it the first yearn if its incorporated in a 997 due to possible bugs.

TIS330ci

what do u shift with?

jetskied

Look in the latest Car and Driver they have an Audi TT article with double clutch. They car works like an automatic with a tiptronic feature. I think it may be a great system, but I still like the involvement of a stick.

kauai_diver

carlos and wmy,

Thanks for the double clutch definition.

kauai

Fanman

On the Audi you can shift with the gear stick in an up & down motion (configuration is similar to many other auto shift units where you push the shifter to one side and push up or down and it upshifts or downshifts but the internal mechanicals are completely different), or they have small buttons on the back of the wheel where you push it on one side and it upshifts, and on the other side and it downshifts. Overall this is the future of shifting, no lag, very smooth.