This will be my first time out w/ these new tires. What is a good recommended starting tire pressure for front and rears on these?


I'm going to an open track day so I can experiment w/ setups, and was wondering what is a good pressure to start with knowing that I may change as I go throughout the day.

What do you guys do use?

 

Scott -- you want 32-36 HOT front and rear, respectively. Typically that would mean you start at 25-28 cold, but it depends on how hard you drive. Ideal range of operating temps (sweet spot of the tread compound) for Cups is between 160 and 220 degrees. Also, these tires need a minimum of 1.5 degrees of negative camber.

 

Thanks. For this event, I'm driving on them about 70 miles to the track and back. Do those temps apply for that kind of driving too?

On the camber, I have stock setup right now. How does that affect me tomorrow since I won't have a chance to change alignment b4 then?

 

Scott.......agree w/ Jacks observations.
Personally I've never run -1.5 in the front.
But otherwise here is what I run.

Every car is set up & handles dif. and my suspension
is pretty far from stock.


Sport Cups---- F....... R
Off track ---- 34........40
Highway----- 36....... 44
City Street---- 32......34
Track Cold--- 25-26.... 28
Track Hot ---- 32 ...... 33-36
160-220 degrees

 

With a stock alignment, you won't have enough camber for even tire wear on the track. But it will still handle just fine.

With my ROW suspension I have 2.5 degrees negative camber in the back, and 1 degree up front. The rears wear very evenly but the fronts still wear more on the outer edges, so I flip them on the rims when the outer edges are just about smooth rubber. I know that's not indorsed by Michelin but you do get a few more days out of the tires.

Also, MPSC's are great when it's hot. If you run in cooler temperatures--mid-fifties or cooler like we get in the Dec-Feb DE's in Texas--they slide a lot.

BTW, you might want to consider a track trailer--near full tread and the MPSC's are ok in the rain. Postively scary when they're worn some.

Sunday on the way back from Motorsport Ranch, I was hoping to run home without needing to change back to the street tires. I knew I was about to get soaked if I started changing tires in the parking lot since the rain clouds were blowing in. So off I went, and in the rain, I could only drive about 45 mph, without hydroplaning.

Once I got from Cresson to Benbrook, I pulled into an abandoned gas station with a nice canopy to change to my street tires. All better then, and off I went.

On pressures, for the street use the same pressure you would use in your street tires.

On the track, I agree with the above. For me, I've settled on 28.5 rear, 27.5 front which puts me at 34-38 psi hot depending on the ambiant temperatures. Some folks start even lower--the lowest I've heard was cold pressures of 22 and 24.

 

As far as pressures are concerned...Tirerack suggests 32f 36r hot for these.

 

I wish I had my MPSC's back on a second set of rims! I found they were an excellent Autox and track tire and very forgiving of pressures.

I typically ran 32 front 33 rear hot track AND street. Although when I thought about I would bump up the street pressures.

By the way these tires were very quiet for me. And the story about rain driving (what there is of it in SoCal) is true, take care.

 

Here's a post from a few months back:

According to a Michelin PSC rep, the following are guidelines for pressure / camber setup: (From last February's PCA tri-region tire tech event with NY-Metro, NNJR, and CVR regions):
Tire Pressures:
Road-racing: 25-28psi cold (front / rear), with a hot target of 32-36 (front / rear).
Autocross: same hot target, but you need to start 6-10psi more cold.
Street driving: normal OE pressures (see your Porsche Driver's manual)
Rain: same as autocross: add 6-10psi more: this will open the tread block more to allow more water "escapage"

Camber:
Negative camber target is between -1.5 and -3 degrees, with a maximum of -4 degrees. No need to go crazy with extreme negative camber, due to improved sidewall technology.

Temperature:
Target temp for dry track conditions is between 160 - 220 degrees F.

 

Agreed.

Scott, Start with cold pressure of 27 and you will heat up to approx 34-36, you will pick up approx 8 lbs.

 

Thanks for all the tips. I just ran 'em today and they were awesome! You guys helped a lot.

Man, I'm never going back to streets now.

After years of street tire driving (mainly because I thought it would make me a better driver) I'm officially switched over and hooked on the Cups!

 

Scott: I'm changing to cups next year. Can't wait! Please describe the break away characteristics compared to streets.

 

I took it kind of easy to learn them. I never really got to any break away, but I did think the feedback was good. I could tell (at least I think I could) tell when I was close to giving away grip. Because I wasn't running a lot of negative camber, I didn't want to go 9/10's or close to it.

The grip was amazing! I'm done w/ streets!

 

I actually like the pressures a litltle higher than that. Anyone else?