At the Autocross Saturday, the base model F Type seemed incapable of both DSC Off and 1st gear downshifts.

Is the concept of turning off DSC completely the same as other Jag's, holding the button for 10+ seconds? It seemed better, but during a sharp turn at low speeds in the wet, the DSC was alive and well, even in this setting. Making matters worse, the car was incapable of a first gear downshift in any mode, ruining the opportunity for a competitive run.

Are first gear downshifts possible? 180 degree plus turns around a single cone are not entirely uncommon. Is there another process to completely disengage the DSC?

 

The way it should work is that a short press enables TracDSC and another press or longer press (I can't recall which) disables DSC. Sure you weren't in TracDSC? TracDSC does loosen things up but DSC is still active albeit with higher thresholds. For the first gear shift, assuming you were in S, it should downshift upon command provided the car knows that you can move to the lower gear (inc 1st) and remain in the acceptable rev range. One issue with these 8 speed cars is that 1st is a short gear. If you were requesting a shift to 1st and traveling at reasonable speed the car may not be able to (and nor should it) accept and act upon the command as the resulting RPM would be too high.

 

interesting, for some reason, I've been paranoid that you can over rev on downshifts. But good to know the computer won't let you downshift if it would cause damage.

 

Well, I'm only going by what I've observed in may car... No responsibility taken for anyone who does manage to do a "money shift" with their F Behavior seems to be that will still shift down if the resultant rev range is "legal" so you can still hit the higher RPM ranges and make it feel pretty bad albeit you're still below the redline range and fuel cutoff etc.

This was one of the things that was talked about a lot when Porsche introduced the PDK on the 997.2. There were a ton of tales about members who had over-revved their stick shift cars (and the ECU in a Porsche stores the over-revs too, anything over a certain rev range was a warranty voider) but you couldn't do this in a PDK - it would also only allow the shift if the resulting RPM post shift was OK.