SPLNDID

I've done some experimenting and found what works with the stock clutch setup.
No quick shifts. Simply allow the RPMs to drop a bit before applying power again... REV matching in the upward gears if you will...
The stock clutch, (even with the limiter removed), cannot handle quick shifting under max power because under quick shifting the plates slip a bit upon contact, (mainly because I don't dump), and that's all it seems to take to heat up the disk and cause subsequent slippage.
Also, I've developed a technique at the track for starting in 1st gear. It emulates the high power drivers where I give the gas, let off and let the decelerating flywheel move the car just a bit as the clutch is engaged ... just enough to then rev up again and "re-grab". It seems that this technique puts the least amount of heat on the plates. Then, during shifts on the track, I allow the RPMs to come down a bit before engaging the clutch. I've had great success with this adjusted technique and am going to stick with it.

For what it's worth...
CB

SPLNDID

... One thing I forgot to add...
The smoother shifting only helped at the track this last weekend. My stook was part of the fastest crowd at Phoenix International Raceway this weekend.
It should be expected that your stook will take a Porsche Boxter... like mine did this weekend, quite easily. The only car faster on the straights in my HPDE2 group this past weekend was a Subaru WRX. He was pulling away in the straights, but I had him in the corners every time. If the driver of the WRX were a bit more agressive, I'm fairly certain that he could have handled the corners as well. But, with the addition of TOYO RA1's, my stook grabbed in the corners and was more than ready to pass the Subaru.
Great car we have here!
Be smooth with your steering and with your shifting and you will see your stook go faster.
Finally, I can't say enough about the positive experience of joining a club like NASA and hitting the HPDE events. Great instructors, and it is an absolute ball going fast in a controlled environment.

Have fun.
CB

Jay2000

I wish that was it, but I have driven three other model years without having that problem, each car for around 15k miles. It is a mystery to me.