Originally posted by DemonSVT:
When you drop the air pressure in your tires that means there is less pressure pressing the rubber to the pavement.
An underinflated tire will only press the outside edges to the pavement and lose the center contact patch. Therefore you will have less traction to get you moving.
Plus once moving the underinflated tires will drastically increase rolling resistance which will slow you down the rest of the track. Top end especially...
We are taking street tires here. Low profile at that!
Not drag slicks. They are designed differently and normally have much more sidewall.
So lowering your pressure will not garner better times.
Also lower pressure tires will not help with wheel hop unless you mean there is a far smaller threshold of traction (since they have so much less) and go right to wheel spin vs staying in the "wheel hop zone" longer.
Hmm, never heard that explanation before. Sounds reasonable though. However i have to say that the correct tirepressure will vary from brand to brand, car to car, and alignment / rideheight.
Personally i run 28 up front and 25 rear with 205/55/16 Poentenza RE-71's on E1 rims. The RE-71's seem to preffer less pressure than the good years that were on the rims when i got them. I arived at this by observing the wear patterns and reducing pressure until i was getting just the slightest bit of wear on the outer edge of the tread under hard cornering. and then fine tuned based on steering input. I'm sure the pressure's will change when i replace these with 215/50/16's.
I have seen plenty of overinflated tires and the associated wear patterns (bald in the center) but i have never seen worn on both outside edges. Could be because most people tend to overinflate.
Thanx for the info Demon, I'll have to keep that in mind next time i adjust the pressure.
