Do the math on this 3866Motorhead Lawyer It's entirely possible if it's an old vehicle with old tires that the cf might be lower than you'd think. I've been chasing my tail with a...
gpsman
The weight distribution effect in the context of this thread is to lower the effective friction coefficient at the highly loaded tires and increase it at the lightly loaded ones. This gives a net drop in friction coefficient, which really just means the 0.85g becomes something a little lower, like 0.8g. (This change in effective friction coefficient is called tire load sensitivity, a funny characteristic of rubber that most other materials don't really exhibit).
Basically what you have is a situation where at any slip angle over a certain point, the force the tires make is more or less constant overall. So depending on the particular tire and loadings involved, if you're running above 10-20 degrees or so sliding angle you're making as much force as you're going to get. I.e., you'll be "accelerating" (decelerating) as quickly as you're going to. If you have a lot of weight transfer occuring than that acceleration is a little bit lower. Still though, if it was running sideways as you described then it's actually likely to be pulling a higher deceleration than you get on the skidpad. Most cars on the skidpad are in a stable trim situation with some excess grip at the rear. Once you kick the vehicle sideways you have more force at the rear than you'd have on the skidpad, so the lateral acceleration climbs up and you get a yaw torque on the vehicle that generally (on a road car, not sure about a pick up) would tend to straighten the car out.
Yeah, I agree. It's probably pretty unlikely it just yawed sideways and stayed like that for that distance. It probably spun around or at least went backwards for awhile. Point being that if any of that happened it reduces the speed that the truck needed to be going to skid 500 feet.
I was involved (as a dumb teenager) in an incident at well over 100mph on a freeway where a friend of mine lost control of his '71 Firebird the time. We spun around three full times and wound up smack in the middle of the freeway facing the right direction (there was no traffic within a mile or so of us aside from those other two, one of which had cut us off, somewhat leading to our piroutte.). We laughed it off later, but in hindsight we could have easily been end. I wouldn't be surprised to find we went well over 500 feet during that little maneuver. That's about 150 feet per second at the start and we were spinning for a long time...
Thanks :-)
