Hit the wall: My ZL1 at Laguna Seca

[Norm Peterson]

Originally Posted by Emvici

barely pulling any rpms, and like you said just got on the gas alittle bit.

Originally Posted by speedmon

You weren't even going that fast and the back end just stepped out.

Exactly why I suspect that a little moisture on the track was involved.

Here's a little clip that shows that even when you know where the dampness is and you're being very cautious the car can still step out on you, and quickly.

I was first car out, and the video picks up toward the end of the out lap shortly before the wetness, so you can see where the wet spot is - I ran wide intentionally, because we were told about where it was.

One lap later (getting up closer to speed everywhere else) I tried very carefully to see if the little puddle was "straddle-able". You'll have to watch closely for the little twitch (at about 1:58) that I was fully expecting as a possibility. Remember that I'm only pushing about a V6 amount of HP and not a huge amount more torque. Needless to say, I ran a wide line through there the rest of that session.

Edited to put in high definition.





Norm

[craig.martell]

Originally Posted by Emvici

wow, its hard for me to believe you lost it under those speed conditions. You were decelerating, barely pulling any rpms, and like you said just got on the gas alittle bit. Very weird. Your front tires oversteered somehow?. too bad you had to tap the wall, the grass was just about to stop you. sad.

Ok, here's the update.

It turns out that my right headlight assembly was cracked, which upped the cost by $950. Total damage: $3600.

I learned a very valuable lesson -- don't run when your tires are about done.

I just put a new set of tires on (the OEM GYs -- which I love when warm). The back tires were definitely at the wear bar. I had assumed that this just meant that I wouldn't have as much traction in the rain. However, when I drove to the shop, I could feel the tires slipping around. I noticed an immediate difference in traction when I picked the car up. And it was essentially the same temperature.

So, what's the difference? Does the rubber get harder as it approaches the wear bar?

Craig

[ZL1-V]

Repeated heat cycling if I recall correctly. I have the same issue now, the tires have become greasy. My motorcycle tires did the same after several canyon runs and track days. It's time for new tires.