[94bird]

I drove an Audi TT with a DCT (dual clutch transmission). Basically, it's a paddle wheel shifter on the steering wheel, but this thing was amazing. We've been working on a DCT for future applications and driving this car was a revelation about how good things can be with such a system.

A friend and I drove the car for a few minutes before it had to be returned to Borg Warner.

2 paddles. Left one downshifts and right one upshifts. An automatic type shift lever was on the center console. If you put the lever in the S (sport) position, the paddles controlled the shifting. Downshifting entering a corner was SMOOTH and quick. Upshifting was also very quick, but a little more line pressure would have made them a bit firmer. There was obviously an electronic throttle since when it downshifted and blipped the engine rpm you didn't feel a thing in the accelerator pedal. The shifts were not clunky or obtrusive like they are in Ferraris with paddlewheel shifters. Audi's system is MUCH more refined.

No clutch pedal was present in the car and I didn't miss it at all.

I can't say enough about how fun this car was. Heck, I was downshifting and upshifting just for the fun of it to see the engine rpm rise and fall with just the flip of a switch. In S mode the engine would stay in a gear for a period of time (at least 10 seconds) even when you had light throttle application, such as a steady state corner where you wanted to hold a lower gear to be ready for corner exit.

No more missed gears or overrevs, faster shifts, left foot braking, think what that would mean over a few laps on a road course. How about over a 12 hour race? This whole weekend when I thought about my drive in the car all I could do was smile.

Now, what would this be like with a RWD car and about 800 HP? Hmm, we shall see . . .

[lateapex]

I am hopeful for the dual clutch systems since they maintain torque to the drive-train throughout the shift. But in street driving, they still have the challenges that all clutch pedal-less manuals face: starting on uphill grades without burning up the clutch(s) and easing forward like in a parking space. I did about 15 laps around Road Atlanta in a BMW M3 SMG. On the race track is where the system is supposed to shine. I liked the perfectly matched downshift revs, but that was it. I really missed the involvement of shifting, and I did not like the shifting action in any program we tried; I think the dual clutch systems could shift as quickly, but not brutalize the drivetrain so.

Many years ago Porsche developed a dual clutch / dual main shaft system in their 962, but never considered one for a production car. They did install that PDK transmission in 2 Audi rally cars in 1985. Of course, computers have come a long way since then. If VW can make it work in the Bugatti with 1000hp and 922 lbs/ft of torque, I’ll be impressed. I can’t imagine how much an automatic transmission would weigh that could handle that torque. I guess Peterbilt or Allison could tell me. Do those 5 second drag race cars shift?

For whatever reason, VW didn’t put a dual clutch transmission in the new Gallardo. They gave it the option of the Magneti system that Ferrari et al use. Below is an excerpt from this month’s Car and Driver road test:

“Computers can’t read minds. In full-auto mode, the transmission is always one step behind, downshifting only after you’ve stepped on it, upshifting just as you spot the hole through traffic. Smooth, jerk-free operation only happens when the driver takes control of the paddles. Even then, scooching up to a parking-lot log is white-knuckle stuff. The clutch fully engages, and the car lurches forward with each brush of the gas pedal. Push one too many times, and the Gallardo’s chin will taste concrete. One time the computer resolutely refused to give any gear, a problem resolved only by cycling the key.”

Shaun, the dual clutch / dual input shaft system is completely different from Ferrari’s and BMW’s. Here is a link: http://news.kak.net/modules.php?file=artic...modload&sid=496

As far as reliability, I am concerned that the electronic control module is bathed in transmission oil at up to 140* Celsius (284* F).