Im having Michelin Pilot Sport Cup tires installed on my spare rims for track days and Im going to have them filled with nitrogen.
I will probably be driving about 100 miles to the track .Does anyone have any recommendations for what pressures I should start out with for DE days. Thanks.

 

Unless you are going to have nitrogen at the track to fill the tires back up to drive home I would just use regular air. If you live in a dry climate nitrogen is even less of a difference. I just would not go through all the trouble for a DE.

Also if you are useing 19" wheels for your track tires I'd go with Toyo R888 over Michelin Sport Cups. The Michelins are not really are R-Comp tire and the Toyo R888 provide a lot more grip, better wear and cost much less.

 

Lockie, going to Morrisport DE this week?

I would agree 100% with what Mike says, I have MPSC on the car now for the street, and wouldn't use them on the track at all, not that much better then normal streets, horrible in the rain, and expensive to replace. I run Hoosiers, and next year I will be getting a set of Toyo 888's for the wet days (unless Yokohama comes out with a R Comp in 19").

If you are he'll bent on MPSC, pm me and I will look up my hot temps that I ran last year.

 

Pure nitrogen is good, but I prefer to use a custom 78% nitrogen blend.

 

And the great thing is that it is available everywhere...

 

Lockie,

I just went through the nitrogen learning curve. I will stick with using nitrogen, because it is predictable, but you need to know the facts. I put them at this link, http://www.tedean.com/Thomas_Dean/Nitrogen_details.html

plus, check out http://www.autotek.fi/pdf/Michelin_Care_and_Feeding.pdf

While every track is different, I start with 22/24 cold, when I get to the track. I carry a nitrogen bottle. They work best at 32/34 hot for my 997S.

 

Thanks guys, Good advice and Links. exactly what I was looking for.
Much appreciated.

 

Ive heard that a lot. Unfortunately I already ordered these and they are being installed. Maybe next time. I'm just curious about the "not really a R comp tire.
They state that it is. would you mind expanding out of interest. Thanks.

 

Sure, the rubber compound on the 19" Michelin Sport Cup tire is not R-Compound, it's the same as the Michelin Pilot Sport II tire that is on the Carrera S and the tread design is different than the 18" Cups.

I had heard about this myself. When I attended a Michelin seminar at the Porsche tent at this years Sebring ALMS race I brought this up and was told that due to the GT3 cars being used on the street and the tire life expectancy of the R-Compund Cup tires, Porsche and Michelin changed the formula on the 19" version of the Cup tires for better street use.

 

Thats very upsetting as I had R Compound Hoosiers and they were fantastic.
Check out page 3 of
http://www.autotek.fi/pdf/Michelin_Care_and_Feeding.pdf

They state in their own brochure that they are R compound ??????

 

Those are for the non N Spec MSPC's.

You will be very disappointed if you have had Hoosier's in the past. I have both, and I am trying to burn off the Cups on the street to use the wheels for other tires...but the rainy season is coming!

 

Sorry NorthVan. this is a little new to me . What are "non N Specs"
Your very lucky you have a trailer . I have to get my tires to the track and if I cant get someone to trailer mine ....I'm driving on Pilots.. I thought this would be better than that...You cant drive the Hoosiers to the track ...

 

N Specs are tires that Porsche has approved in conjunction with the tire manufacturer. I don't think that anyone can tell you what the difference between a N Spec and Non N Spec tire is, it is just advised to not mix them.

I made the decision last year that I wanted better track tires, as well as the ability to take my car home if it had a breakdown (radiator, tire, etc), so a trailer was a must. I have tracked my milage and number of days of use and have almost paid for the trailer in one season...everything after this is a bonus!

 

The stock Cups that are for Porsche 19" wheels are not R-ompound rubber and they have a different tread design than the other Michelin Cups. I have seen these 1st hand to see the difference and spoke to Michelin at the Sebring race Porsche tent about this.

If you had Hoosiers and went to 19" Michelin Cup's for Porsche you will be a lot slower at the track.

 

I have them mounted but havent been on the road with them . I wonder if I can ask for a refund as they are Misrepresented in their brochure