Sorry - couldn't find the last pertinent thread to tack this on to so I started a new one. The following was written by Todd Serota who runs the Tracquest events (and is one helluva good driver with a LOT of experience. ) The 36/38 numbers were advice to a Porsche driver. I'd start the M5 at 35/32 for the track- (or whatever that guy said in that post last week...)
Quote:
There are many who tell people to raise their tire pressures when they go to the track, on the theory that this needs to be done to prevent the tires from rolling over. In most cases, this is just plain wrong. Indeed, most people run their pressures too high on the street because of factory recommendations that are made for reasons other than optimum performance.
I'd suggest you do two things to see for yourself. First, bring some chalk with you to Thunderhill on Friday. Before going out, you apply it in various places, going from the tread over the sidewall. When you come in from your session, look to see how much of it has been worn away. This is commonly called "chalking your tires" and will give you a rough indication as to whether or not they're rolling over. You can also simply look at the point where the sidewall meets the tread if you know what to look for, but the chalking method is very simple.
Second, try starting out at 36/38. Drive a session, paying careful attention to how the car feels. Then drop your pressures 4 pounds all around and try it again. See if you can tell the difference, and whether it's good or bad.
Perhaps someone could answer this question: Why does Spartanburg run such high pressures? Are they trying to make the cars a little more forgiving for presumably inexperienced drivers? Or are they trying to save the wheels? Or something else?
BTW, the original tread was "I'm so Ashamed"
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143366
'00 E39 M5
'97 E39 540i six speed
I had the Bridgestone PP02's fitted today and I know you have them. What pressure have you found works best for road use (no passengers)?
P.S. I can only compare worn Dunlops to new Bridgestones but the car is transformed ... I could hardly stop driving it ... it made the corners more fun than before and the handling less twitchy. Seeing the tires fitted for the first time surprised me how much tread you can see from the side ... looks like its ready for an off-road hike!
The fun really started this morning on the way to the dealers to have the new tires fitted ... couldn't resist smokin' the old ones before we parted ... seems that DSC is there to prevent the axle tramp.
I guess I should name my threads more like the content, sorry Greg. Does anyone know the lowest safe pressure you can run on the Dunlops? I'm sure it was too low, but there was virtually no understeer when the fronts were at 25 psi. Maybe the manufacturer has some info. I'll look into it.
I spoke to the technical advisors at Dunlop corp and they couldn't answer any questions. They did say to run the tires lower than the maximums on the door placard, but didn't say how much. they said I should call my dealer(what a joke) or BMW technical assistance, which is what I'll try next. I'll keep you informed.
some sage advice re: tire pressures for the track
Linear Mode
