Can't say how long they'll last, since they are a long ways from the end,
but for a data point, the G-Forces on the front of my MR2 now have about 90
runs on them. Looks like they may be halfway gone. No concrete surfaces
yet, but so far I'm amazed. I've been staying towards the high side on
pressures (40 psi). It seems that they really, really wanted heat cyling -
they seem to work better as they age. Or maybe I'm just getting used to
the car.... I can't say about the rears, as I changed sizes for the past
two events. The original set is in really good shape, as is the new set
(which has 8 runs locally, 12 runs at San Diego, and 35 at San Berdoo).
BTW, the rears seemed to get really unhappy when they got really hot in the
last two rounds of the Challenge at San Berdoo. They seemed to lose grip,
so I spent a lot of time WAY sideways, but oddly enough they were
controllable and I never spun - surprising in an MR2. I wish we'd tried
cooling them down. I dropped the pressures for the last round, and it
didn't seem to make any difference. I am sure they wore a lot more in
those last 5 runs than in the rest of the event, as I was sideways with
them lit up scrambling for traction for an awfully long time....
Oddly enough, they seemed to grip very well off the line no matter what - I
bogged the car a bit off the line in the same runs it was getting sideways.
Paul and Meredith Brown
MR2: "Not the easiest car in the world to work on"
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