Limited slip differentials on vintage F cars

With Alfa, BMW, and other similar ZF, LSD clutch disc setups, we could preload to varying %s, with more metal / clutch discs /shims. One of the better mods, was to change the
( I am guessing now to what extent) ramp angles to a wider angle, say from 43deg to 53 deg+/-, and 'soften the 'bite'.

We will look into the Dino setup (probably same) and change the angles there too. It really is a vast improvement. Probably same on a Daytona, really depends on driving style, etc.

My friend in Italy has developed new clutch discs that eliminate the 'chatter' when turning 90% into a garage / box / pit. Top quality as tried on Alfa.
With all things being equal on the set up, no more chatter, and better progression.

Happy Easter!
Alberto

 

I have read quite a bit regarding what Porsche does with ramp angles particularly with the 930 Turbos both under acceleration and deceleration.
My goal was to get the LSD, which was badly damaged, back to original specifications. I was able to locate a book produced by ZF explaining the relationship of preload to engine torque.

 

The Modena Engineering differential from Australia has 2 different ramp angles built in so it can be tailored to your needs.
On the ZF diffs clutch plates can be stacked steel/friction/steel friction for greater lock up. In most cases they were delivered steel/friction/friction/steel to reduce lock up and make the cars a little less treacherous on slippery roads.

 

I have never seen friction to friction,
friction, steel, friction, etc. yes.

Regards, Alberto

 

Brian is correct for the diffs I had apart so far.

 

Not sure about the earlier cars but from 308 up through 512TR all were delivered that way.

 

I was able to track down an original ZF workshop manual where they show a wide variety of combinations.

 

could you please post this here?

 

A friend is carefully copying the booklet, as soon as I get it back I’ll scan some of the pages.
It’s very informative and goes to great lengths to explain that clutch pack stack heights and breakaway torques correspond to engine torque.