Hoosier R3S03 Tire Pressures?

[304065]

From the Hoosier Web Site at www.hoosiertire.com:


1800-2200 lbs.
39-42 Hot
31-36 Cold

2200-2600 lbs.
40-43 Hot
32-37 Cold

2600-3000 lbs.
42-46 Hot
32-37 Cold

over 3000 lbs.
43-48 Hot
32-38 Cold

Really? I ran an old set at Pocono last weekend at 23 front, 25 rear and managed to get the wear all the way out to the edge of the tread pushing the car to about 8/10. But the logbook for the car shows the PO racing with 39.

Also, someone recommended that I set a 3-5 pound pressure differential between front and rears, so that running HOT, the pressure in all 4 is the same. Can this be RIGHT for a 911, with a 65% rear weight bias? The fellow who told me this was a hot-shoe 944 guy but it strikes me that having the motor in the back will necessitate higher pressures (just like we use thicker torsion bars).

For some reason there is no specific thread on this in the archives- would love to hear from those who have BTDT.

[Randy W]

John, IMO, the pressures on the Hoosier site are high for a 911. I would guess your car weighs 2500 lb with driver. Try 34 front and 38 rear hot.

[gumba]

I have a ' 73 targa, weighs 2750 lb. w/dirver, 225's on front, 245's on rear. I run 32/34 cold, 38/40 hot. I notice a real loss of grip around 43 hot. I use this for time trialing.

[304065]

That's what I figured- race weight of my '71 is 2249, but I probably check in about 2280. Which would suggest that lower pressures will work.

[gumba]

We took some temp. readings across the tire, (I believe 200 being ideal) and found 40 lbs. hot to be the best. I've tried lower pressure and can feel the tires rolling on the rim under hard cornering. You might try a temp gauge.

[dad911]

I shoot for 40 hot also, all the way around. My car(s) weight 2250#. Took me along time to believe they needed this much pressure.