[Will]

I'm considering buying a base 2013 Carrera with PDK, but without Sport Chrono, 12k miles, and 2 months out of warranty that's exhibiting some (I think) weird behavior that I wanted to run by you all. When the car is at a stop and you remove your foot from the brake and floor the throttle, the car's revs seem to increase faster than the car is gaining in speed. In short, it feels like the clutch is slipping to around 4,500-5,000 RPM in first gear before finally locking onto the flywheel. At this point the car accelerates linearly, and all other gears seem to lock immediately. It exhibits this behavior in both normal and sport modes. The car seems to lock onto the flywheel much earlier with more modest applications of the throttle.

PDK issue or normal operating behavior? If it's normal, it feels like this is VERY bad for clutch life; is it? Any technique to launch the car without this much slippage?

Thanks in advance for your help!

The Fat Kid

I have a .1 C2S and usually in Sport+.

There is a little manual-like slip from a dead stop, but it should feel pretty normal by ~1.5k RPM. The feeling is exacerbated a bit if you floor it, but the clutch should not be slipping until 5k RPM.

One way to test the clutch: Find an uphill section on the highway; put it in 7th gear while in manual mode; floor it without hitting the detent.

It seems like this is a private-party sale, so take it to a local dealer to have the issue checked out.

[Will]

Thanks for the help. I know that this does not occur in C2S Sport Chrono cars, but the engine tuning is so different that it almost seems like the car might be tuned to cover up for lack of low end torque in the 3.4l engine. Will be interesting to see what other base model cars experience.

The Fat Kid

I floored my C2S in S+ mode from a dead stop strictly for, um, research purposes this afternoon. I had to get around someone at a traffic light, so I glanced down at the tach and pretty sure it immediately jumped to ~3.5k RPM, sat there momentarily before I moved, and then I launched forward and the tach only started to climb as my MPH caught up to the RPM.

I have not used launch control, but it seems like flooring a 991.1 C2S will mimic launch control by slipping the clutch. The 991.1 base probably uses a higher RPM point since it is down on HP/TQ vs the 3.8.

Noah Fect

PDK is a clutch-based transmission. If you floorboard a traditional manual, what do you expect to happen, exactly? If you engage the clutch before the engine spools up, you will get a lurch and a bog, if you don't stall the car entirely. If you slip the clutch, you will get a better launch at the expense of clutch life. If you wait for the engine to bounce off the rev limiter before releasing the clutch, you will find out whether your tires or your clutch have more grip. Even if the outcome isn't clear at the time, your mechanic will be happy to do the necessary detective work.

The PDK controller has to make exactly the same judgment call. Fortunately, it has the advantage of working with fluid-bathed clutches that are a lot more tolerant of slippage than traditional discs. Hence the tendency to allow the engine to rev up to a moderate RPM before engagement.

In fact, the 991.2 and 982 cars simulate "intermediate gears" by allowing the clutch to slip heavily on an ongoing, everyday basis. At some point it might as well be a locking torque converter.