I drove the future last week, Bye bye heel and toe! Options

[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 . . .

[231go]

No experience w/ the audi setup, but I have driven many of the BMW SMG's and those are fun. Didnt really have much of a chance to really open one up, but did to some high RPM upshifting and downshifting and was having a blast with it. Much better than the porsche and lexus systems. Those damn buttons are so hard to find when you really get the car moving. Plus those systems are nothing but glorified slugboxes.

[Bud M]

Is this in production or development?

[94bird]

Shaun, drive the Audi system in the TT. It's only available with the 3.2V6 engine, but should be in dealer showrooms now if you can find one. The Audi system is leaps and bounds better than the BMW for what I hear. I haven't driven the BMW system personally however.

http://www.audiworld.com/features/tests/2004tt32.shtml

[231go]

The BMW system did have its downfalls, nothing compared to the ferrari setup. Unfortunatly I didn't have much of a chance to "test" that one out. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dry.gif) I have driven number of Audi TT's both 2wd and quattro. I however wouldnt recomend them to anyone who drives hard. Dad used to work at a dealership where they sold VW's and the construction and quality of them is crap. Never seen an audi upclose to see how well they are put together, but I have a feeling that they are really similar based of what VW and Audi has to offer. 10K for a quattro transmission, no thankyou.... But they are fun cars to drive and do have a cool look to them

[94bird]

Keep in mind Shaun I didn't love the car. I just loved the DCT. They will be in other cars very soon now, and as soon as any enthusiast drives one he or she can't help but love it.

[231go]

Keep in mind Shaun I didn't love the car. I just loved the DCT. They will be in other cars very soon now, and as soon as any enthusiast drives one he or she can't help but love it.

Gotcha, but how much did you get to drive it? Was it at a track session or just around the block? Im currious how well it can rev match a downshift while keeping the car stable. That was one of the main downsides to the lexus and the porsche systems is that is was more of a "almost-sport" mode. Where as the car would be fun to take down the backroads and push buttons while running at a moderate speed, but if you were to really push the car hard and deep into a turn it would not do so hot. The BMW system was pretty good w/ it and the ferrari system was almost perfect(from what I have read). Has this system matched the ferrari setup or is it like the BMW setup and hopefully a little more reliable?

[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).

[231go]

Interesting reading. It also brings up a good point, which more technology are you sacraficing reliability? The hydro clutch setup does what its suppose to 90% of the time and its completly driver controlled so there is no one to blame but yourself when the shift goes bad. But the question would be is the added speed and technology of this system worth the cost of the setup and the possibility of it failing? This mainly directed to the problems w/ the computer temp concerns as well as the low speed manuvers which is something I did notice while driving the BMW's.

[94bird]

I think based on the descriptions I've read of the other systems the Audi system is much more refined and useable for every day driving. You can put it in automatic mode and it acts just like an automatic transmission if you want, but in sport mode it matches revs on downshifts quite well. Each of us drove the car for about 10 minutes around the "Lap of Chrysler" roads. It's private property for Chrysler so there are no police if you know what I mean. My boss had it for 3 days and he also drives pretty hard. No complaints at all.

Yes, this setup is worth it for a racer, no question. Let's face it. For a normal street car that's just your transportation all you need is an automatic transmission. It's only when you want to have fun that a manual tranny shines. This DCT does both, and does the manual transmission portion of it MUCH better.

[tonycook]

I've had my M3 with SMG for about a year and it has very rarely performed imperfectly. I've had the car at Barber and Talladega Gran Prix Racetrack and have been impressed with its performance. It's very easy to drive fast, but you have the feeling that you're cheating because of the advantage of the SMG.

[Chris 96 WS6]

Bob,

Actually Top Fuel rail dragsters and funny cars do not shift....they don't even have a transmission. a 5 disk clutch is used which is built to slip off the line until 1/2 track where the heat from slippage and 6500hp melts the disks to the friction plates. From there on out it is 1:1 direct drive and the tires grow in diameter due to centrifugal force, which provides a gearing change for the car. You have to rebuild it every run but considering they rebuild the engine every run too its not much additional work, LOL.

So no...high HP drag cars do not shift....they used to run 2 speed powerglides but that was decades ago.

I don't want to change the subject (especially considering this is an autocross/road race board (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif) ) but I do want to post this. Some wild facts about top fuel cars a friend sent me:

* One Top Fuel dragster 500 cubic inch Hemi engine
makes more horsepower than the first 4 rows at the
Daytona 500.

* Under full throttle, a dragster engine consumes 1½
gallons of nitromethane per second; a fully loaded 747
consumes jet fuel at the same rate with 25% less
energy being produced.

* A stock Dodge Hemi V8 engine cannot produce enough
power to drive the dragster supercharger.

* With 3000 CFM of air being rammed in by the
supercharger on overdrive, the fuel mixture is
compressed into a near-solid form before ignition.
Cylinders run on the verge of hydraulic lock at full
throttle.

* At the stoichiometric 1.7:1 air/fuel mixture for
nitromethane the flame front temperature measures 7050
degrees F.

* Nitromethane burns yellow. The spectacular white
flame seen above the stacks at night is raw burning
hydrogen, dissociated from atmospheric water vapor by
the searing exhaust gases.

* Dual magnetos supply 44 amps to each spark plug.
This is the output of an arc welder in each cylinder.

* Spark plug electrodes are totally consumed during a
pass. After 1/2 way, the engine is dieseling from
compression plus the glow of exhaust valves at 1400
degrees F. The engine can only be shut down by cutting
the fuel flow.

* If spark momentarily fails early in the run,
unburned nitro builds up in the affected cylinders and
then explodes with sufficient force to blow cylinder
heads off the block in pieces or split the block in
half.

* In order to exceed 300 mph in 4.5 seconds dragsters
must accelerate at an average of over 4G's. In order
to reach 200 mph well before half-track, the launch acceleration approaches 8G's .

* Dragsters reach over 300 miles per hour before you
have completed reading this sentence.

* Top Fuel Engines turn approximately 540 revolutions
from light to light!

* Including the burnout the engine must only survive
900 revolutions under load.

* The red-line is actually quite high at 9500 rpm.

* The Bottom Line; Assuming all the equipment is paid
off, the crew worked for free, and for once NOTHING
BLOWS UP, each run costs an estimated US $1,000.00 per
second. The current Top Fuel dragster elapsed time
record is 4.441 seconds for the quarter mile
(10/05/03, Tony Schumacher). The top speed record is
333.00 mph (533 km/h) as measured over the last 66' of
the run (09/28/03 Doug Kalitta).

Putting all of this into perspective:

You are driving the average $140,000 Lingenfelter
"twin-turbo" powered Corvette Z06. Over a mile up the
road, a Top Fuel dragster is staged and ready to
launch down a quarter mile strip as you pass. You have
the advantage of a flying start. You run the 'Vette
hard up through the gears and blast across the
starting line and past the dragster at an honest 200
mph. The 'tree' goes green for both of you at that
moment. The dragster launches and starts after you.
You keep your foot down hard, but you hear an
incredibly brutal whine that sears your eardrums and
within 3 seconds the dragster catches and passes you.
He beats you to the finish line, a quarter mile away
from where you just passed him.

Think about it, from a standing start, the dragster
had spotted you 200 mph and not only caught, but
nearly blasted you off the road when he passed you
within a mere 1320 foot long race course."

[2002ssconv]

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/ohmy.gif) (IMG:http://www.frrax.com/rrforum/style_emoticons/default/blink.gif) Daimn!

And I was thinking it would be cool to drive one of those TT Audis. They kinda sound like crap now. Thanks. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif)