Tire pressure? for Ed R. and other Club Racers
07-06-2002, 02:45 PM
#1
User
Thread Starter
Tire pressure? for Ed R. and other Club Racers
Ed and others,
We have gone over this in depth but I have one more Question.
Groundwork: My old Dunlops -SP 2000 E's- are rated at 51 psi max I accepted the car with the pressure sitting pretty close to max.
I picked up on a pressure thread sometime later before I recieved an owners manual.
Obviously, the TP was close to max COLD but the handling AND ride were great. NOW, I know that Porsche recommends a significantly lower TP. However, when I lowered theTP to recommended psi, front and rear, there was noticeable wear within 300 miles so I assumed right or wrong that if the PO had the tires balanced and aligned at near max pressure if I lowered the TP I affected the balance. There being, approximately, 12 -15 psi difference when considering front and rear psi recommendation. I bumped the pressure back up to the mid 40 psi range and wear has slowed or stopped at least on the inboard side of the carcass.
If I like my new Kumho's I'll stick with them, if not it will be back to the High Pressure Dunlop's -maybe the 6000 series- .
The question: If I really want to thump the twisty's, plan for the occasion, take into consideration cold versus heat expansion PSI differences ... does handling improve or degrade with a set of tires inflated towards the high side of their rated max pressure. Keep in mind the old Weissach is not a Euro, 86 1/2^, S-4, GT, or GTS so I don't think I'll be doing much steering with the rear wheels.
TIA
John S.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
We have gone over this in depth but I have one more Question.
Groundwork: My old Dunlops -SP 2000 E's- are rated at 51 psi max I accepted the car with the pressure sitting pretty close to max.
I picked up on a pressure thread sometime later before I recieved an owners manual.
Obviously, the TP was close to max COLD but the handling AND ride were great. NOW, I know that Porsche recommends a significantly lower TP. However, when I lowered theTP to recommended psi, front and rear, there was noticeable wear within 300 miles so I assumed right or wrong that if the PO had the tires balanced and aligned at near max pressure if I lowered the TP I affected the balance. There being, approximately, 12 -15 psi difference when considering front and rear psi recommendation. I bumped the pressure back up to the mid 40 psi range and wear has slowed or stopped at least on the inboard side of the carcass.
If I like my new Kumho's I'll stick with them, if not it will be back to the High Pressure Dunlop's -maybe the 6000 series- .
The question: If I really want to thump the twisty's, plan for the occasion, take into consideration cold versus heat expansion PSI differences ... does handling improve or degrade with a set of tires inflated towards the high side of their rated max pressure. Keep in mind the old Weissach is not a Euro, 86 1/2^, S-4, GT, or GTS so I don't think I'll be doing much steering with the rear wheels.
TIA
John S.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
07-06-2002, 07:24 PM
#2
User
Thread Starter
BTW
The new Kumho's are very quiet.
I waxed Pattycakes while waiting for the tire change...cruising 40 minutes later and it started raining. Really! Rain in the West Texas Permian Basin, honest!!! Wax vapors , maybe?
Hydroplaned -slowly- on a off ramp, no brakes, just light counter steer. The 928 for me appears tobe easily recoverable in a slide.
What was it I was supposed to remember about new rubber?
The new Kumho's are very quiet.
I waxed Pattycakes while waiting for the tire change...cruising 40 minutes later and it started raining. Really! Rain in the West Texas Permian Basin, honest!!! Wax vapors , maybe?
Hydroplaned -slowly- on a off ramp, no brakes, just light counter steer. The 928 for me appears tobe easily recoverable in a slide.
What was it I was supposed to remember about new rubber?