What are your thoughts on PDK for SoloII? If I look at a different car this winter for next season I'm on the fence on PDK. The last race had a very tight turn that tightened just before the finish so I could have used first gear. I was always behind on the turn. My question is that just rookie driving or a spot for PDK to down shift or both.

 

It's course dependent. The ability to upshift/downshift instantly and effortlessly is invaluable, but it adds about 70lbs you now have to lug around the twisty bits. Not many autocross course designers will let a Porsche hit 3rd gear, but if your local courses have a lot of slow corners, you may find PDK is a huge benefit. Performance-wise, I think it tends to be a wash. Sport chrono+ is more useful on PDK than manual cars, so keep that in mind while you're shopping; it doesn't just change the shift points, but also the speed and abruptness in which it shifts.

One other benefit is that you can keep both hands on the wheel at all times and concentrate more on your driving line and technique. There was an anecdote in Excellence a few years ago where Walter Rohrl was faster around the 'ring in a Turbo S PDK than the manual, and found that his times were virtually identical whether he left it in D or selected the gears himself. If Walter Rohrl can't beat the computer, what chance do we mortals have? It's very smart about shift points, so you can just leave it in D most of the time and it'll just uncannily shift right where you need it to without you having to so much as tap the paddles; even in D, you can tap the paddles to get it to shift if it's not doing what you want.

 

I haven't found that I need 3rd. it was this last race that was fast on a cold track with a very tight turn just before the finish . The car just revved to slowly. I have been a die hard stick guy as I was the last guy with a 4 speed in my drag race group when I was still into that. I want what is fasted now.

 

I'm expecting PDK to be a big help for Solo. I did some modeling and the PDK really helps at slow speed, like under 60mph, which is where you spend most of your time at autocross. That's why the spec for 0-60 (for a 981 Cayman S with sport chrono) is 0.3s better with the PDK.

You get better speed off the line, but you also get to change down and use first more. With my current car, I can't see breaking even on a change down unless the speed dips below 16mph, which is pretty rare. The half a second interruption in the drive train when you change back up out ways any gain you get by the extra acceleration from changing down. (I drive a pretty low horsepower car, so your results may vary.)

An example of a model I did (for a 981CS) is exit a corner at 30mph and accelerate straight for 100m. If you change down to first with a PDK then back up to second, you gain over half a second, despite changing up. You can do the same thing with a manual, but the longer gear change time would mean you're 0.1-0.2 sec slower, and you have to have the confidence to ram the stick into first when the revs are going to be 5k after the downshift.

I'm also thinking Sport+ auto mode is going to be the fastest way to do this. In sport + it'll change down anytime you'd have spare revs after the changedown. You don't even have to think about changing gear.

I've yet to test these theories, I'm waiting for the locals to schedule some sluch dates.

 

If I find myself needing third in the Cayman, then someone's not done their job properly. I should be able to get to 85 in second and that's too fast for a Solo II course. The rules have been tightened up this year and say (sec 2.2A) It used to say "not exceed freeway speeds", which was quite loosly interpreted, and there was consternation with some 80mph speeds. I hit 61mph on one course, with only 121hp, I was not amused.

 

There's a local track near me that's fairly slow and technical as far as tracks go, but I hit 3rd gear in 5 different spots. I do VERY well at that track, thanks in large part to PDK.

 

I have hit 60+ all the time with second now and hit 68 at 7000 RPM. I never bounced off the limiter in second. I did that once at my first race second pass some dumb a** didn't hit second when he should have I can see where PDK can help with going back to first on tight turns. I don't have the power of those X51 motors with my 3.6 at 320HP. That's about the same as 987.2 Boxster S. I weight my car at the Match Tour and it was just over 3200 lbs. so a Boxster should be a few hundred pounds less. So those 987.2 with PDK are starting to look good. Plus I can move from a 07 to a 10 or 11 for the same money that I have in the 911.
Stay with the 911 or go to the 987.2 with PDK I'm in no hurry.

 

987.2 is classed very poorly right now for SCCA autocross; it's straight-up against 987.1S in AS and the 987.2S is against the elise/GT3 in SS. And the "right" option package for autocross is a unicorn: it doesn't exist. I searched for 2 years for a 987.2 with PDK, SC+, PASM & LSD and never saw a car that was even close; I eventually compromised when I found a 2010 987.2S with PDK and SC+ (no PASM or LSD) cheap enough that I could afford to retrofit PASM to it and still come out below KBB. If you search long enough, one may eventually come up; maybe by that time, it'll be classed better, who knows.

 

I'd run your model with some much shorter straights before reaching any conclusions. It's rare that you can execute a first gear turn and go immediately to full throttle, extremely rare to have a 100 m straight, and pretty much unheard of to have a 100 m straight after a first gear turn, at least on a national-type course.

I'm sure there's an autocross acceleration advantage associated with PDK, but I think it's far smaller than you're envisioning. Audi TT owners have a similar transmission choice, and both manual and DSG cars have been successful at the national level, but as far as I'm aware there's no consensus on one being strongly preferable to the other.

 

I saw a Cayman unicorn last year for sale but it's the only one that I have seen. What about a Spyder the thing I see wrong with that is the price that is still $55,000 - $65,000, plus I'm not sure about using that as a DD.

 

I agree. While PDK addresses the speed/ease of shifting, it doesn't really address the inherent difficulty of controlling acceleration in first gear.

 

It wasn't meant to be typical, and I'm considering local, not national courses. Its a best case, 100m was about as long a straight as we could fit on our lot, however, I'd say 30mph corner exit is pretty typical. I'd also not call 30mph a first gear corner, unless you're using a PDK and that's the big advantage. Also if you can make 0.5s best case on one element, you can do pretty well with a variety of not quite so best cases on the rest of the course.

I'm sticking by my analysis that PDK is a big win, despite the 60lb weight penalty, and also its an advantage in two ways, making more of the course first gear, and less interruption in the drive train when changing up (which you can do more often).

 

What would you consider a Cayman unicorn?

 

Why is there one out there?

 

As for using first in a race, this last race we had a very tight hairpin just before the finish. This turn was maybe about 20 and never came back to RPM through the traps. When my co driver was driving I could hear that the car never came recovered in time and that is what I felt when I was driving. Is that worth getting a car with PDK for one turn in one race, No. But and this is a big but, once you have a tool in the tool chest you find a new use for it. That is the question, is this the tool that you didn't know that you were missing or needed.