Prescott weekend

[Terry Clifford]

Launch Problem.
Using my 918 C.S at Prescott at the weekend I found that traction limiting was almost non existent with launch control on in sports plus.
Far too much wheelspin before traction found and then the revs disappear before picking up again. The tyres are P zero's and the temperature was about 11degrees, so not the most ideal set up, but I would be interested to here from you guys' with PDK about you're experiences as to put it mildly I was not impressed. (please don't tell me I should have bought a manual)!!!!!!
T.C.

 

[ralphmusic]

I am not sure my experiences are that relevant but, having used launch control once with 5 starts it did improve as it learnt the friction coefficients. I have a friend in the USA with a 3.8L Powerkit engine in his 981CS who uses it mainly for drag racing.... He has never mastered the starts and I assume part of his problem is anticipating the Christmas Tree lights within the Launch sequence timing window. I generally found P Zero tyres lacking in grip but I guess there will be several components for success in getting CS with launch control off the line.

 

[Terry Clifford]

Thanks for your comments Ralph, I think maybe the reference to P zeros is the relevant part. Incidentally why is there a sentence in the handbook (in bold print) that says "remove foot off accelerator" at the end of the bit about using launch control.

 

[garyw]

Although not in a Porsche - but an flappy paddle gearbox, I had the same issue getting off the line in Prescott last summer.

In the end I stopped using launch and tried a more gentle approach, which worked for me.

However this was just with passenger rides, so not essential to get the best timings.

 

[AndrewT]

I'm not sure whether you'll find this to be relevant or interesting but at the Gurston hillclimb a couple of weeks ago I compared the 64ft times of several Porsches which were competing, including a 981 Boxster 3.4S with PDK which appeared to struggle to get traction off the line. The 2.9 Cayman and 3.4S Boxster were on road tyres, the others were on slicks or 1B tyres I think.

Edited to say: I hope that the following displays OK.

Date Run 64 ft (seconds) Bob's 911 16/04/16 t2 2.2 Bob's 911 16/04/16 t1 2.24 Bob's 911 16/04/16 p2 2.37 924S 16/04/16 t2 2.6 Bob's 911 16/04/16 p1 2.61 924S 16/04/16 t1 2.65 944 Turbo SE 16/04/16 t1 2.77 944 Turbo SE 16/04/16 t2 2.8 Cayman 3.9S 16/04/16 p2 2.84 Cayman 3.9S 16/04/16 t2 2.88 Cayman 2.9 16/04/16 t2 2.94 Cayman 3.9S 16/04/16 t1 2.96 Boxster 3.4S 16/04/16 t1 3.00 Boxster 3.4S 16/04/16 t2 3.03 944 Turbo SE 16/04/16 p2 3.06 Cayman 2.9 16/04/16 p2 3.07 Cayman 2.9 16/04/16 t1 3.08 Boxster 3.4S 16/04/16 p2 3.09 944 Turbo SE 16/04/16 p1 3.27 924S 16/04/16 p2 3.34 Cayman 3.9S 16/04/16 p1 3.38 Cayman 2.9 16/04/16 p1 3.46 Boxster 3.4S 16/04/16 p1 3.55 924S 16/04/16 p1 4.07

Conditions were damp for practice 1 & 2 and dry but cold for timed 1 & 2.

 

[Terry Clifford]

Gary, That's what I ended up doing, but the times for 64ft were slow !!!!!

Darkmatter, Yes your post is relevant and interesting, confirming again that launch control is not that effective and especially so with std. road tyres. Gurston being downhill and next weekend Shelsley being steep, it will be interesting to see how much, if any ,effect that has. Thanks both for your info.

T.C.