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      10-05-2012, 01:03 PM   #21
Pete_vB
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Drives: '69 GT3, GT4, 1M, 912
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Quote:
Originally Posted by ayao View Post
I'm curious about your opinion regarding the sweet spot for tire/rim combo on the street?

On the street I can't safely exceed the limits of the stock PS2s, but I found that at the track and in particular on an autocross circuit the limits were relatively predictable and easy to control with DSC off. I'm just trying to assess how PSS's would affect this balance.
As the tire gets wider but the rim stays the same a few things happen:
  1. grip goes up
  2. slip angle is reduced
  3. tire response gets slower
  4. hydroplaning resistance goes down

Now #2, slip angle being reduced, basically means the breakaway is more abrupt and also that you can't drive the car quite as sideways. #3 means turn-in is slower, and feedback from the tire is reduced. So one could generalize that wider tires are faster, but more difficult to get the most out of and arguably less fun due to the slower response and less sideway action.

The PSS is in my experience more progressive a breakaway than the PS2 despite the fact that it's grippier, so I'd say it's easier to drive overall, but the turn-in is already slower. Going wide as well will make it even gripper and slower turn-in. Either way, I think your choice is largely between more ultimate grip and feel/ feedback.

I've gone with the stock sizes on both sets of my wheels, so you know which way I voted on the street. For the track I'd go wider (ideally on wider rims) and use different tires again.
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