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      10-02-2011, 10:23 PM   #1
SlamMan
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Corded a Tire at the Track. How Do I Avoid it?

I participated in the local BMWCCA performance driving school last weekend and managed to cord a tire. Unfortunately, like an amateur, I didn't even realize it had happened until this afternoon when I put my stock brake pads back in.

It was the inside of the front passenger side tire. I would have guessed the drivers side would wear more as the track is clockwise. This was my first time out with the Ground Control sleeve over kit with the camber plate. I had the camber tilted all the way in. I was told that would put it at about 3.5 degrees. I'm not quit sure where my tire pressure was because I neglected it, again, like an amateur.

I assume this was some combination of camber and tire pressure. These were the original tires and they needed replacing. I just want to make sure I don't trash a new set of tires. What do I need to do to make sure it doesn't happen again?
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      10-03-2011, 12:06 AM   #2
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What was their justification to tell you to set your camber to 3.5? I'm just wondering without any real advice, probably bigger amateur than you.

I do think it might help more to say which track this event was at. Elevation changes and camber in turn of the track could be a factor. Also, alignment specs?
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      10-03-2011, 01:59 AM   #3
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How old were you tires? Mileage and were they only used primarily on the track?

+1 to your alignment too?
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      10-03-2011, 08:02 AM   #4
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Well, 3.5 is probably a bit much for most street tires. You might try 2.5 and see how you like it. When I had camber plates on a previous car, I occasionally moved them between street and track without an alignment, but I had marked the plates for the respective settings, so I was at least close. You will also loose some toe when you add camber, and depending on where it’s set, you might have a bit of toe-out in the track camber setting, which most folks would not like for street use.
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      10-03-2011, 10:49 AM   #5
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Your "street setting" for camber and alignment all factor into this issue. If you have the car aligned to BMW specs for daily driving and then you bung in -3.5 degrees for a track day, you're likely to have some problems, not from excessive camber but from excessive toe-out.

Moving the top of the strut inward changes the toe setting towards toe-out. If you go two degrees worth (say from -1.5 to -3.5) you'll gain a lot of toe-out, and that's likely what caused the uneven tire wear.

The other thing to consider, though it depends on your tire choice, is that -3.5 degrees is more camber than most tires will respond well to. They'll corner ok, but you'll get a bit squirrelly under braking.
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      10-03-2011, 10:53 AM   #6
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You are right in that you should have been monitoring tire pressures and temps throughout the day. You should at least make it a habit to visually inspect components before each session.
My opinion is that 3.5 camber will not kill the inside of your tires in one day, but the near .4" of toe out that you probably had will!
When I do a full sweep of my camber plates for track days, I also adjust the toe. Moving the plates 2 deg also adds .4" toe out. Changing toe is very easy and repeatable. I marked my tie rods and adjust them as part of my track prep.
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      10-03-2011, 12:14 PM   #7
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I don't remember all the alignment settings off the top of my head but I know the camber was set to 1.5 for street. I'll have to check with the shop I was working with on the toe. The shop I was working with said 3.5 would be good and I could just tilt them all the way in.

The tires are the original PS2 and had about 11.5K miles on them. The track is High Planes Raceway.
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