good hands

Thank you Rick Deman for the great article in this month in Excellence. Some excerpts below of the testing. 1.5 second improvement for a pro driver who says it will benefit us amateurs even more. Me thinks a 100lb penalty was not enough ?

Full article here http://www.excellence-mag.com/issues...2#.UxcmTmeYZD4


The Cayman’s manual transmission is precise, but the PDK dual-clutch tranny is magic in this car, as it executes shifts with incredible speed. The benefits of PDK are especially evident for amateur drivers, as the shifts are not only faster but will be much smoother as well, which helps to keep the car better balanced.

“PDK gives you incremental gains on upshifts, but on the downshifts it gives significant gains,” says Longhi. “Braking and downshifting using heel and toe is fun, but PDK eliminates the question of completing a proper downshift on the approach to corners, so you can focus 100 percent on going faster. Amateur drivers usually lose the most time compared to pros in that phase where you roll off the brake, balance the car and roll speed through the first and middle of the corner and then pick the throttle up coming off the corner. That phase is a night and day difference with PDF versus a manual.”

Rick DeMan is also a pilot and can relate the advantages of PDK on the track to flying an airplane. “As a pilot, you have to focus on so many things, but you also have to think ahead with things like the navigation, which is called the workload of the pilot,” he says. “There’s a tremendous amount to do, and if you ever get behind on your workload, that’s when things become dangerous, so any kind of automated system in a plane puts you in a better position to do your workload. On the race track, anything that lightens the workload of the driver will make him more effective. Let’s say heel-toe downshifting takes 30 percent of a driver’s mental capacity to get right every time. If you remove that, the driver has 30 percent more mental capacity to get his line right and focus on steering and braking.”

As DeMan also points out, it’s not an uncommon occurrence for amateur drivers to miss a downshift and ruin a motor with a manual transmission, which is another thing you never have to worry about with PDK.

The benefits of PDK are greater for less experienced drivers, but as Nick Longhi showed in back-to-back laps in these Caymans, the faster shift times will make even a pro driver capable of turning quicker laps.

Longhi went out in the black manual transmission car first and after a couple of warm-up laps set a fast time of 2:28.9. Before going out in the white PDK-equipped car, weight was added to the car to equalize it with the 2,732-lb weight of the black car (the white car weighs around 100 lb less with its carbon-fiber bodywork). Once tires got up to temperature, Longhi stopped the clock with a fast lap of 2:27.4 in the PDK car, a full 1.5 sec. faster than the manual transmission Cayman. The PDK car may have had a slight advantage with seven gears versus the six in the manual car, but the gap in lap times was large enough that it was very evident the PDK was significantly faster.

Reliability of the PDK transmission has also not been a problem with the track cars DeMan has built so far. Track-day and race cars are still pretty rare to find with PDK (the 911 GT3 Cup uses a sequential dog-type gearbox), but DeMan has found that the transmission has held up very well when driven in more strenuous conditions at the track. “We’ve had great success with the PDK transmission in track cars so far,” he says. “They’re strong and still shift great after many miles of track use, and we haven’t had one failure yet.”

Our day with the DeMan Motorsport Caymans at Monticello may have proved emphatically that PDK will get you around a track faster than a manual transmission car, but the real eye-opener was how stunningly good the Cayman is with major mechanicals from the 911. Porsche has continuously improved the 911 over the decades, and it’s one of the world’s great cars, but driving a Cayman with a 911 engine makes you think this is the kind of car that Porsche should have as its flagship performance model and one that they should put some racing support behind.

ninjabones

I think a better comparison would have been between a 991 PDK vs 991 manual (both sharing far more components and gear ratios). I think they downplayed the benefit of the 7-gear PDK Tranny over the 6-gear manual tranny: "there may have been a slight advantage"... give me a break. There is a night-and-day difference between those two boxes. Now comparing the 991 models would be more telling.

ProCoach

^^This^^

As Rick said, it's not all quantitative benefit, it's fewer errors, MUCH better focus and better driver execution.

The less load on the driver, the better they do. And for a longer period of time...

d15b7

I'm curious as to if he was running the PDK in sport plus auto mode or if he was manually shifting it in the comparison?

I agree with the author that it is so easy to drive the PDK car compared to a manual car, especially for a novice.

Veloce Raptor

In addition to the comments above, IMO the advantage of PDK iin this car is the greatest on tracks where is a LOT of shifting (COTA, Daytona, maybe even VIR). And also IMO, 100 lbs was not nearly enough to equalize...

KaiB

It's probably all true, and all good, but...

...this recidivistic old fart will continue with his analog cars, happily double clutching and heel/toeing around the track. Bring the modern **** on!

n2deep

Also curious if the car was manually shifted.

I just bought a PDK for my Cayman track car and I don't intend to manually shift it. It's a brave new world ...

User 52121

I've driven a PDK car in anger on the track twice now - and yes, it's pretty awesome that it's just always in the right gear. I just left it in "auto" and it was sorta like driving a video game.

I also autocrossed a PDK car twice and THAT, on the other hand, drove me a little nuts leaving it in auto - kept wanting to go down to first gear.

The downfall to the current PDK cars (maybe the 991 GT3 is different) is that you can't switch off the PSM with it - and the Cayman I drove on track both times, the PSM was a HUGE annoyance. Once they get that sorted out, no doubt the PDK is the way to go if you want to win races.

I'll stick with my clutch pedal though. I wear my ability to heel-toe like a badge of honor, dammit!

n2deep

PSM has been removed from my car. We started from scratch including removing the wiring harness. The Cayman is being built to go as fast as possible within a given weight/hp. If I want to heel-toe I'll have to drive my SPB.

jcastle

I thought PDK wouldn't run without psm. Please share details.

Rick DeMan

You're sort of right..

The PDK will NOT be able to access the Sport or sport Plus shift patterns and shift quickness with the PSM disabled or in fault..

Rick DeMan

PDK as well!!

Dr.Bill

Do the PDK cars require any additional transmission cooling?

Upstate101

Unless it's a race why are incremental improvements in lap times so critical, particularly if they come as a result of technology that eliminates the need to learn and execute heel/toe downshifts? Why not just hook up the GPS to Google and have a totally autonomous driving experience? That way you can text, email, make business calls while setting scorchingly fast lap times.

Rick DeMan

I'm sure you're a blast at parties..