Originally Posted by
markk
Funny how one broken CWP makes the diff crap.
The problem that people don't consider is not hp its torque and where in the rpm range that occurs.
Other considerations with the Ford units are the ally cases. They distort under big torque, this unloads the mesh of the CWP, it jumps a tooth and munches itself into oblivion.
This is the case with the front 6" and all the rears (excpt 9").
Lots of work was done when using for competition, first was don't use the 3.9 front, the physical tooth count is too low on the pinion to get any cut into it. That is why step offs came about for the MT75.
There are motorsport backlash settings, this does affect life and noise though.
If i could I would upload a video of us launching the Escort on 235 Pirelli slick tyres on launch at 1.5bar boost at 3600rpm with over 500nm torque. No wheelspin in the dry.
Still using a 7.5" rear but a home made front diff/shafts setup from the rear of another vehicle. Same ratio front and rear, both plated LSDs.
I know of loads of 2wd saffs over the years that have shredded the cwp with power of 500hp plus.
As Andy mentioned once you uprate the diff the next weak link is the cwp hence people started to use the supra stuff as it’s bullet proof in cosworths.
There are def not lots of other options out there for diffs to fit in a saff, without lots of fab work and r&d it makes sense to go with what’s tried and tested.
Cheers Paul
Its not that dear a conversion considering