C2 Positraction

[Rich G.]

Today, being stuck in the house by this #@$%$ Blizzard, I was watching that Speed Channel show that has the guy from Lengendary Motor Cars on. He showed the 64 with some "ZO6" options on it..FI J56 F40..big tank, but he did not call it a ZO6. Anyway, he made an "agressive" start and spun the left rear for a good distance, leaving a singe steak of rubber. I thought with posi, there should have been 2 streaks of rubber. Am I just confused by "My Cousin Vinny" or what? And no, I'm not going to try it with my car to see what happens. My memory of terrorizing the neighborhood in 1963 in a 62 300hp car was that it left 2 streaks.

Anybody else see this?

Rich Giannotti

[Joe C.]

Re: C2 Positraction

Rich:

It should lay down 2 parallel patches of rubber. But that is assuming the coefficient or friction is fairly equal between the contact patches of both rear tires. If the difference between them is greater than the collective coefficient of the posi clutches, then 1 wheel will slip.........thus, "Limited Slip".

I am sure that someone can describe this in more elegant terms, but that is the basic idea.

Joe

[Joe R.]

Re: C2 Positraction

Rich,

That old 64 is broke or someone didn't put a posi in it when it was "Restored" because posi was one of the boxes that had to be checked when the FI was selected.

Your memory is good and the 64 is bad!

Regards,

JR

[Duke W.]

Re: C2 Positraction

As the positraction clutches wear and loose preload, the diff begins to act more like an open diff, and one wheel can break loose. I suspect this car has an old worn out positraction, however, if the traction coefficient is sufficiently different between the two wheels and if enough input torque is applied, even a good posi can allow one wheels to break loose and if you let is spin, the posi will burn up in short order and you'll have an open diff.

There was no Z-06 option in '64, but all the equipment that was available with both the first and second iteration '63 Z-06 special performance equipment package was available as separate stand alone options in '64.

Duke