Trackday experience
 

Had the pleasure of instructing in a 2014. I always seem to get the high horsepower assignments like Z06s and Vipers. Anyway the short of it was that the Turbo is awesome on the track. The torque can get you in trouble, but it's serious Fun. Thought we might have tire or brake pads issues, but none at fast B group pace.

A couple of nits. Brake distance sensor annoying and stereo on at start up.

slightly OT OP - apologies

but I've been through all 18 pages of the 991T forum and can't find anyone who's stripped and raced a T or TS ...
is there any info on that idea at all?

(not one I would subscribe to, but a guy who wants to join our race is keen on the idea of 4 wheel drive and 4 wheel steering after spending some time at Spa & NBR with one)

thanks!
Matt

You can take care of keeping the stereo from coming on at startup by pressing and HOLDING the off button (left knob) for a few seconds. That shuts it completely off. Pressing it briefly only puts it into suspend mode and it will then resume once you start the car again. When you turn it "off-off" it will stay off until you press the knob to turn it on.

What do you mean by "brake distance sensor"?

Good tip on the stereo! :thumbup:

Not sure if mine came with a "brake distance sensor" but curious what he means also... :p


:cheers:

Assuming he's referring to ACC.

Very few comments about the TT or TTS at DE's so appreciate the post. The reply about stripped/track versions of the TT/TTS is a good one. FWIW, the opinion of several pro drivers who have a lot of experience with the 991 GT3 and TTS tell me that they have similar track times. Interesting that the only nits were the radio and the ACC and not the tires, which I assume were stock P Zeros. Would like a bit more info about getting trouble with the torque.

Brake sensor is only if you ordered the driver asset package.
Also, first hing I did when car arrived at the dealer, was ditch the P Zeros for MSC2s. Currently tracking with Trofeo Rs, which are great!

I have the ACC on mine and it does ring out warnings sometimes on the track. Just on a couple of occasions it's added braking that I didn't call for with my feet. I do wonder whether that's a such a good idea -- I mean I hope it doesn't reach in somtime and upset the balance of the car at a bad moment...I guess maybe we have to have faith that the programmers won't command something that makes the situation worse(?).

First time it chimed the instructor riding with me thought the car was broken...guess there's not a lot of experience with this system in the track day crowd as yet :)

Just over 15k miles on my car on the original Pzeros including 4 track days and the rubber was all done. I put Super Sports on this time and I have to say they seem more sticky and talkative (good howl :)) in the track regime based on the one day I have on them so far.

I did notice the tire pressures at the end of the day were way up there...I suspect I have to get a lot more serious about managing tire temps and pressure from this point. Seems like I'm getting fast enough now that it's going to matter in future. [seems like a confusing subject though, if anyone has a good primer I'd take a pointer...there seems to be all sorts of advice but not much consistency in that and I'm not sure how much of what I've found so far I can apply to my car/tires...]

The stock P Zeros stink. Not enough traction. Just replaced them with Michelin Pilot Super Sports for Goldrush Rally 7. Haven't driven on them yet but I know from other cars they have a softer rubber compound and are stickier. Would have loved to get the Michelin Pilot Sport Cup 2s but car is a daily driver and wanted more wet traction than those offer.

I tracked my 2015 Turbo S during April in our local PCA chapter's Spring Fling Driver Training Event. This was driver training and it is not racing but we were on Brainerd International Raceway. The training was held on the shorter race circuit which excluded the +1 mile long straight.

I will post more details later but I can say the car was waaay more than I needed and it performed flawlessly. The exception was the front tires' low traction limit.

It's called PAS which is part of the ACC package:

Adaptive Cruise Control including Porsche Active Safe (PAS)

Available as an option, this cruise control function regulates your speed according to the distance between your vehicle and the vehicle in front. If you have set a cruising speed, but have begun to gain on the vehicle in front because it is driving more slowly, this is detected by the radar sensor.

The system now reduces the speed of your vehicle by restricting the throttle or gently applying the brakes, until the distance that you have preset is maintained. Your vehicle will now continue at a reduced speed. If the other vehicle decelerates further, adaptive cruise control will continue to reduce your cruising speed – even down to a halt.

For additional safety, if the system detects that the distance from the vehicle in front is decreasing, it will also prepare your vehicle for braking by precharging the braking system so that the brake pads are already in light contact with the brake discs. However, drivers still have to perform heavier braking themselves.

As soon as the road ahead clears again, your vehicle will accelerate back up to the cruising speed originally set.

If your vehicle approaches the vehicle in front too quickly, Porsche Active Safe (PAS) will issue audible and visual warnings. In addition, the system briefly jerks the brakes and if necessary initiates target braking, with any braking pressure applied by the driver being increased within certain system limits.

That's what it does alright. The situation that it seems to kick in most for me is approaching low speed corners, especially say at the end of a straight. I can see clearly that the car ahead of me will be turned in and well out of the way by the time I arrive at the turn in point. However, the system sees the car ahead slow dramatically and the rate of change of closure increases rapidly and I suspect it can't predict that the turn is about the happen.

On the highway with the same rate of change of closure scenario, and probably less options on where to go aside from straight ahead perhaps, I can quite easily see that the system would be doing the right thing...grabbing your attention and potentially adding brake.

Thanks - look fwd to hearing more :thumbup:

This indeed is a hallmark of your improvement. You carry more speed into the corners, which of course loads the tires more, and as a result, they heat up a lot more than before. Porsche telemetry (at least in my 991 turbo) gives just tire pressures, not temps and pressure like they do in Ferraris but I find that setting the display to show TPMS pressure is very useful. Each tire and car differs but I try to keep pressures relatively close to 3-4 psi above cold settings (I haven't tracked my 911TT yet so can't be more specific).

This requires either bleeding off a few psi before you start your track session (and being careful to put some heat into the tires the first lap or two before pushing the car really hard), or adjusting pressures mid or between sessions. Some tires' grip falls off more steeply than others with excessive pressure or heat, and I've found that worn tires or those with more high heat cycles in them can also have steeper fall off (a well-used set of RE-11 Bridgestones on another car gave me a track ride that was a bit too thrilling once, when they overheated).

I was going to swap my stock P Zeros for Sport Cups until I read about their temperature range and wet performance. My car is my daily driver so I didn't want to compromise street for track performance (during what passes for winter where I live, it gets cold and (normally) wet enough that I wouldn't want to be out on SCs with the car). I'm likely to put on a set of MPSS when the P Zeros are worn out. When making that same switch in other cars, I've found the Michelins to ride slightly better and produce less road noise in normal driving compared to the P Zeros, in addition to having at least as good, if not better grip in both wet and dry.

As for ACC, thanks for explaining what a "brake sensor" is. It's interesting you can't seem to turn it off for track use. I suppose it's useful for collision avoidance on the street or highway, but annoying if not dangerous for track use if it thinks you're going to crash and especially if it kicks in at the wrong time (like mid-corner at to near the limit).

Thanks for the advice, Need4S -- very useful! I followed your basic process of dropping some pressure on arrival at the track and did it again later in the day.

Essentially I was aiming to stay at ~40 PSI on the rears and ~37 on the front during hot laps for these PSS tires. I read elsewhere of the PSS's that much over 40 and they start to get greasy. I started with 32F and 35R cold (and put the TPMS system into "comfort, part load" mode to keep it quiet...that recommends 34F/37R). Late morning the rears were up to 42 at the end of a session so that's when I dropped a couple more pounds and from there it held fairly steady...at least as far as I can tell from checking the dash TPMS readings on the front straight, I didn't watch it while under load in the corners ;)

At any rate, I had pretty good traction through the day; certainly better than last time out. That is particularly a "win" because the track surface was a lot hotter and its slickness started to be a factor. Some of the others who apparently already know what they are doing with tire management were talking about the track starting to go away through the afternoon. Hmm, now I need to figure out how to go a bit faster so I can notice that too, perhaps ;)

Once the tires cooled all the way down to ambient, TPMS readings (and my pressure gauge, more or less) read 30F/33R -- so I put a bit more air in them this morning for normal road use. I guess I'll start at 30F/33R next track day and see how that works.

Oh, and a correction to something I said above. I guess I must not have figured out how to turn off the PAS sytem properly before. I tried again yesterday and got the grayed out warning symbol on the MFD. In this configuration I had zero warnings or intrusions on the brake pressure. Nonetheless, the ACC option remains one of my favorite gadgets on the car -- killer feature for highway driving.