Cogito_Ergo_Zoom

Had a very fun time at Cresson MSR this weekend. We ran a 1.8mi clockwise configuration. Mostly wasted a new set of Pirellis in the process, but it was worth it.

The 991 is a very satisfying car to drive on the track, but this weekend also highlighted a few things I'm going to have to adjust to or address before I track the car again.

The brakes were great, as usual, even with the stock pads on their 2nd DE. Temps were rising and I didn't change the fluid beforehand, so I was concerned this might be a problem, however they never even came close to showing any fade even on a very hot and humid second day. The pads will need to be changed soon but the discs are still in very good shape.

I was also interested to see how the temps responded in the hotter summer ambient temperatures. As usual, the coolant temp may have well been painted on the display at 200F. Oil temps were well under control the whole weekend and peaked after my longest session at 246F. Oddly enough, I've seen much higher temps from hard street driving.

My brand new tires, at least on the outside (left) are basically shot now and will need to be replaced again. Keeping pressures in check on the second hotter day was challenging. I also feel like I'm reaching the limitations of the stock alignment based on the tire wear pattern.

Overall the PDK performed well, however there were several times it surprised me with ill timed downshifts where they weren't appreciated. For example there were several low / medium speed corners where the exit was off camber and I preferred for the car to be in third, so I would shortshift only to have the PDK bang down into second as I approached full throttle nearing corner exit. I realize the car is probably trying to tell me it's smarter than I am and I should just leave it in full-auto mode, but I'm beginning to find this more than a little annoying. What's the point of a manual mode if the computer is still going to override your decisions anyway?

Regardless, the car is a blast to drive on the track and I'm already looking forward to my next event.

This was my fastest lap of the weekend, set on the next to last lap of the last session on the last day. Tires were off their peak and very greasy at this point so it was a little sloppy, but great fun, that's for sure.

milrad

Cool video.

kosmo

first of all good job. what mode (S, S+) were you in when the PDK kicked down?
Also in the video it appears the PDK was in Auto.

SB

Can you please share your Harry's lap timer setup? ie. how the phone is mounted, which OBD dongle are you using, gps bluetooth, etc....

Cogito_Ergo_Zoom

Thanks. You didn't see the part where I outbraked myself and went off at Horseshoe three times over the weekend.

I'm always in Sport +, sometimes with PSM off, sometimes with it on. I'm positive the PDK was in manual. If you look closely in the video you can see the top of the shifter tilted slightly to the left.

Cogito_Ergo_Zoom

Sure, it's HLT Petrolhead Edition v17.0.6 running on a iPhone 5.

Mount is a RAM mount which is a great piece of kit and as long as you have it tightened and secured properly with clean surfaces on both sides it will not come off. I've got it mounted on the rear window slightly offset to the passenger side at the very top. It will take a little trial and error to get it level and at the right viewing angle.

GPS is the Dual XGPS 150 with the firmware update. Once you pair the two it's pretty much set it and forget it. The iPhone and HLT will find it every time it's switched on and in range. I just place it in its rubber base and put it on the back shelf behind the rear seats so it has a clear view to the sky and there's no risk of it coming off the dash and distracting me at the wrong moment.

I'm also using the Kiwi PLX wifi OBD II reader. As you can see from the video, you will get mixed results from this at best.

kosmo

I have heard that the PDK software will override the drivers input under 2 sencarios in Manual mode:
1. When a downshift will cause over revs
2. When the accelerator is pushed past the "kick down" (floored ) point and a resulting downshift will NOT result in an over rev.


Do you think #2 happened to you?

Cogito_Ergo_Zoom

Yes, it was definitely #2. I realize the computer is saying "Hey, you're off the HP/TQ curve, stupid, you should be down a gear" and I probably should have been. But the point was that I wanted to be at full throttle in 3rd exiting that corner with a little less available torque to keep the car stable in a pretty off-camber corner even if it meant sacrificing a few revs down the straight. I wish it would let me make the choice is all I'm saying.

Bah, I'm nitpicking. It's an awesome car and I'm lucky to be driving it.

kimf70

What is your experience with the Kiwi PLX wifi? have you experienced much disconnection with its wifi connection?

mtony

Wow! No wonder you finished off the tires. That course is like a skidpad!

Cogito_Ergo_Zoom

Not really. You just have to remember to take out of sleep mode before you start your next session and check that's connected and working before you mount it. It's the accuracy / sync that's the main problem.

Cogito_Ergo_Zoom

Yeah, you're definitely dragging the tires through those long off-camber corners for what feels like an eternity.

SB

Thank you.

kitwetzler

One thing that is a bit tricky is that as far as the computer is concerned, you are full throttle just before the kickdown. You can try not hitting the kickdown switch...

I agree, though, that's annoying! My M3's M-DCT was good about ignoring the kickdown switch in manual mode.

Cogito_Ergo_Zoom

Yeah, I guess the solution will be just having to manage the throttle inputs more consciously in those situations and avoiding putting it on the bump stop too early. Kind of defeats the purpose of short shifting though...

You would think that they would have avoided any automatic transmission-like behavior in Sports+. I don't mind that happening in normal mode or even Sport. For example, I like the cool little throttle "double tap" hack that will automatically drop you into the powerband in 4th when you're curising around in 7th on the freeway and decide you need some passing power.

The PDK giveth and the PDK taketh away.