BAD, BAD, BAD!!!!

 

i like the black rims alot

 

I'd be afraid, ... very afraid, of any wheel not certified by Porsche for this car.

Why?

After reading about how critical the grease used to coat the wheel-to-keeper-nut interface is, I'd be worried they might fly off the car at speed!

My old 962 won the '86 Sebring race on three wheels. I don't want to have a less-than-four wheel experience, ever, with my CGT.

 

"My old 962 won the '86 Sebring race on three wheels. I don't want to have a less-than-four wheel experience, ever, with my CGT."

Ok Mike - now you got my interest! I have to ask...what the heck happened ?

 

Well, ... as you may, or may not, know, center-lock wheels have to have some sort of torque transfer device to transmit the forces from the wheel to the hub. Just the friction between the back side of the wheel to the outer face of the hub being clamped together by the holding nut isn't anywhere near substantial enough to get the job done.

All center lock wheels of which I'm aware use "drive pins" that look a lot like wheel studs, except without the threads. These smooth drive pins are anchored into the hub and fit into socket holes in the back side of the wheel flange. It is a tight, but not too tight, fit for the hub pins in the wheel socket holes.

Now, ... if the drive pins get a little wonky, which is wont to happen from time to time from hard use, the situation deteriorates. If the pins are not securely anchored, and can wiggle just a tiny amount, this allows the wheel to slip a tiny amount relative to the hub. It'll slip one direction under brakes and then the other direction under gas. When this happens to any substantial degree, the wheel nut can "walk right off" the spindle after enough speed-up/slow-down cycles

That's what developed during the Sebring race. One of the front wheels (IIRC, the right front) came off the car due to wonky drive pins at some stage of the race. The car pitted and a new wheel was put back on. This may have happened twice. I don't remember very well. Then, with a few laps to go, and the car in the lead, the same damn wheel pulled right off again!

It turns out that the roll stiffness of a 962 is so high that removing one of the front wheels will not allow the brake disk on that side of the car to touch the ground. In fact, if one were to drive only through corners where the missing wheel is on the inside of the turn, it hardly changes the car's cornering ability at all. This condition upsets the balance of the car, for sure (makes it push a little ), but only cripples its lap times when negotiating corners where the missing wheel is on the outside of the turn.

The crew decided to continue on three wheels to the end of the race because pitting for a new wheel would be more risky for the win than just suffering the slower pace.

QED, the car won on three wheels!

 

That's simply amazing - thanks for sharing that!

 

what an awesome story