Agree it is not the car...I worded my post poorly. Thanks for the suggestions - I know next to nothing about what could cause it other than the tires themselves...thanks!

 

Of course the other thing is we are well into October, cooler weather lowers tire pressure, even in Atlanta...

 

Less now that global warming has raised the temperature everywhere.

 

Its all those black cars, that's what it is...

 

To help make up for the black car, I am doing my best to hasten the conversion to alternative energy by helping burn all the fossil fuels.

 

I'm liberating frozen methane.

 

Well this thread seems very lacking in political correctness!

I think I'll join in by saying that I took my black 991 to my first DE (ever) this past weekend at Roebling Road and aggressively burned some fossil fuel.

I LIKE IT!

To stay somewhat on topic, tire pressure adjustments were not needed and I hope to be faster next time!

 

Uh, oh.

Nitrogen or air, whatever gas goes in there is gonna heat up and expand and increase your tire pressure when you start loading the tires with hard braking and cornering. The difference can easily be an increase of 5 psi in 5 laps, or even more and sooner, when going from parked to hot laps. Of course that's not likely to happen to you. Being a first time novice in such a capable car its unlikely you'll be able to put that much heat into the tires just yet. But you should definitely notice some increase during each run.

The way we teach those of us with lesser cars is to do a few laps then pull off into the hot pits and check tire pressures. Right now I can hear everyone screaming no way you're crazy I paid good money I'm not wasting one single lap checking friggen tires! Which is what I thought too until I tried it and realized the 'time out' clears the head, improves focus, and gives key feedback and familiarity with your tire pressures. Which is really, REALLY important.

Anyway, this is not every session you do this just the first one of the day. And with TPMS you can see any time you want anyway. Still, it is a Good Idea to pull off and adjust.

Tire pressure is easily the one thing you can adjust that will significantly impact the way your car feels and handles, and how much total grip you'll have. The trick is to get really familiar with the way things feel at ONE particular setting. That means bleeding air every time it goes up by even 1 or 2 psi. Don't worry that it drops between sessions. It'll come right back the first few laps. Learn how the car responds at this setting, whatever it is, and you'll be in a good position to evaluate changes down the road.

 

Since my post at #10 of this thread, I have spoken to one of the service people at my dealer.

They abandoned the N idea months ago. Not because it was a silly idea, but apparently it interferes with the TPMS, giving false readings of "0" sometimes.

Hmmmm . . . . I think he's been breathing the N himself! I didn't have an issues with my N filled tires for the 8-10 months before putting air in my tires.

Anyone hear of this?

 

When ever I teach DE, be it a novice or experienced student, before I get into their car, I ask them what their tire pressure is.

If they don't know, I will not go out with them until they know and all four tires are within the correct range for their car. This is just too important.

If they lose track time . . . I and them are still around to complain about it.

 

As stated above in yet another of my many wonderfully entertaining yet marginally pertinent rants (#12 if you want to know) the air we breathe is already 80% nitrogen. Nitrogen is also very inert. Its hard to imagine an additional 20% being severe enough to cause TPMS failure. More likely the truth is they figured that since so many people bought into.... aw never mind....

 

Thank you for the advice and I recognize the car is in a different league than the driver. I will try to follow your recommendations at my next event (hopefully back at Roebling on Nov 9-10). The dealership did the tech inspection (dealership does them for free) and set the pressures on the tires. I noted that the pressures the dealer set did NOT match the comfort settings in the manual...nor the full load settings. I will ask them the reasons why before I go again.

My instructor and I checked the tire pressures before and after a run to determine how much they were changing. There was a waiting period after each run and the tires seemed to largely cool between each 25 min session I could participate in. This DE was aimed at introducing a bunch of novices (like me) to the hobby and I recognize how fortunate I am to be starting with such a car.

 

Tire pressure ranges are wide and vague. As long as you're within the range of the manual there's no right or wrong but only what gives you the grip and feel you prefer. In general, towards the high end the tires will be very responsive with incredible road feel but less than maximum grip. Towards the low end the tires will feel less responsive with a smoother ride and less than maximum grip. Somewhere in between will be a range of just 1 to 3 psi where grip is max and responsiveness is very good. This ability to tune tires by adjusting air pressure allows you to adjust your car to your preferred experience by balancing front and rear. The factory preference is for the rears to be quite a bit higher than the fronts. Part of this is for load, but a lot is because they know this gives the driver the greatest handling safety margin. In effect they are recommending you use a little extra understeer. Not saying anything wrong with this. Rather I am pointing out that, again, there's no right or wrong its all down to what works for you.

Pay no attention to cold tire pressures. Only working pressure matters. Always try to check immediately after a run. Bleed as necessary. Sure it will drop by your next run. Does not matter! It will come back up during the next run. Usually as the day goes along everything gets hotter, you're bleeding a little after each run. Or not. Does not matter. Only thing that matters is keeping your on-track pressure constant all day long. Most people have been taught to set it cold and forget it. Might be okay for the street, but tires can get a lot hotter on the track. If they do and you don't bleed you can find yourself with a car that's squealing and sliding excessively because the tires are over-inflated, too hard and losing grip. Just remember to add air on the way home or first thing the next day.