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Discussion Starter #1
Can anyone suggest Michelin Pilot Sport 4S cold and hot tire pressure guidelines for a PCA DE at Road America? Air temps will range from 60-75. There might be intermittent rain on one day.
 

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Generally speaking, in dry conditions start with 28-30 psi cold. Bleed off air as necessary to maintain approx. 36 psi hot. Adjust to your liking.
In wet conditions, start with factory-recommended cold pressures. The tires won't heat up very much in the rain as the water carries the heat away from them, and the higher cold pressures will keep the rain grooves open to best extract water. Again, adjust to your liking.


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I start at 30 cold and monitor pressure after every session. On warm days, the pressure will increase up to 36-38 after one session. I will bleed out pressure to get back to 33-34. Then repeat. Your driving style, car set up, track and temp will affect the best pressure. Try different hot pressures until you are happy. Just don't go too low or too high, as it is bad for the tires and your lap times.
 

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Thanks. 36 hot felt perfect for these two days on this fast track.
I'm glad that it worked out well for you. Please tell us more about your track driving experience!

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Discussion Starter #7 (Edited)
I'm glad that it worked out well for you. Please tell us more about your track driving experience!

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Thank you for asking.

Prior to last Monday and Tuesday's superb PCA Nord Stern Driver's Education event at Road America, my last time in a race car driven in anger was at Grattan in 2017, where I was blindsided during a club race in Turn 3 and launched 30 feet through the air. L 4-5 was displaced forward from the impact and hard landing. A partial spinal fusion and residual nerve damage followed.

My orthopedic surgeon said that wheel to wheel racing was out of the question; any future spinal trauma would create what he called "failed back." My wife, who is both My Surgeon General and Chief Justice of Our Supreme Court, affirmed the ruling from which there was no further rehearing or appeal.

I felt the pain and heard the words, but didn't feel the fear.

I liquidated the race team and equipment and bought the Boxster. I joined PCA, and affiliated with Nord Stern, because it was more about motorsports than cars and coffee.

Moth seeks flame.

The PCA event this week was my first.

I knew that there would be no passing except in designated areas, which pleased My Surgeon General. At the Drivers Meeting we learned that this was most of the track except corners from turn in to track out. I didn't disclose this to My Surgeon General.

I did disclose the "no passing except by contract" rule. This makes great sense to me. My Surgeon General concurred. You can't pass unless the car being passed invites you with a turn signal or hand signal. If cars fail to propose a contract when circumstances dictate that they should, they are black flagged and receive a lecture from the course steward.

We lined up on the false grid just like in a club race. We entered the track pretty much like in a club race. The track was green and we were racing except for the no passing in corners rule, the contract, no official lap timing, and no published finishing order.

None of these differences compromised the experience, which was essentially that of racing if one wanted to.

Lots of good drivers wanted to.

I thought those days were done.

Well done, PCA and Nord Stern, and thank you for controlling the risks without substantial dilution of the essential experience. I have had maybe 20 road race weekends at Road America over the years---tension, crowds, noise, limited track time, stressed race cars often failing.These two tranquil and even bucolic PCA Nord Stern days in a modern, reliable but feral-enough Porsche at Road America were the best ever.
 

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Well done, sir. I can tell that you have learned to NEVER question decisions of the Surgeon General and Chief Justice.

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I think there were 4-5 cars from Great Plains Region PCA running in this event. They always have a good time. Cars would include a gray 09 911 S, a yellow 17 911 GTS, a red 16 Cayman GTS, and a white 15 Cayman S.
 

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I had C4,5 and 6 fused with a titanium plate three years ago. Cause was related to ligaments loosening due to osteoarthritis. I lost some minor feeling in the right hand before, but the six month MRI after the surgery, the neurosurgeon told me that the spinal cord was dead center in the canal and that I could not have had a better outcome. He made no limits on track driving, although I only do HPDEs.

Getting back on topic...

My 4s tires on my Boxster heated up 6 to 8 PSI initially at 65 - 70 MPH highway driving (As indicated in the instrument cluster). Gas Mileage was lower by 2 MPG over the Mich P Alpin 4 winter tires I took off. I had the tires aligned after approximately 200 miles. Before alignment, the right rear got 2 PSI higher than the rest. Alignment showed that tire was slightly more out of line than the others. Post align - the tire that increased in pressure when driving moved to the right front, but overall pressure increase has dropped to just three or four PSI on all the tires. Yesterday, after a 40 mile drive, I got 33 MPG, an increase of 1.5 MPG over the most recent comparable drive. I assume the tires are finally breaking in.

V6
 

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Discussion Starter #11 (Edited)
My surgeon, like me a serious skier, said "Don't ski the blacks any more, ski the blues." HPDEs are like skiing the blues. Risk is diminished, but it is there. Now that I understand what these events are all about, I may buy the version of the HANS which can be used with the 3-point belt. The Fire and Rescue EMT who tended to me at Grattan said that the HANS I was wearing then probably saved my life. The words, and indeed the memory of the incident, still resonate.
 

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My surgeon, like me a serious skier, said "Don't ski the blacks any more, ski the blues." HPDEs are like skiing the blues. Risk is diminished, but it is there. Now that I understand what these events are all about, I will buy the version of the HANS which can be used with the 3-point belt. The Fire and Rescue EMT who tended to me at Grattan said that the HANS I was wearing then probably saved my life. The words, and indeed the memory of the incident, still resonate.
Are you looking at the Simpson system, or from some other vendor?
https://simpsonraceproducts.com/hybrid/hybrid-s-3-point-belt-compatible/
 

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Discussion Starter #13 (Edited)
Looking at the Simpson, but open to suggestions.

My only hesitation is wondering whether it is redundant with an air bag system.

That might prevent the rapid forward movement of the neck and skull which, in a car with no bags and a 5 or 6 point race harness holding the torso relatively firmly (even the best race belts give a little with sufficient force), causes the basal skull fracture and spinal cord injury. I was topping 130 at Road America and lapping at the end in the 2:50s. Fast enough to make this topic relevant. Dale E. hit his last wall at 60-70.

Will try to research.
 
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