Any Cobras built with open diff?

[1795]

I had a welded rear end on my MGB race car and other drivers were warning me that it would push through corners (it was my first race car) and I never felt like it was pushing, seemed to go through smoothly. However, being my first race car, with the exception of the Formula Fords that I used in my race school, I really had nothing to compare it to at the time. The Cobra with the Salisbury is pretty neutral in the corners. The only times that it wants to step out is when I do something stupid.

[eschaider]

Originally Posted by Morris

I’ve used many different Differentials over the course of time......the welded up diff was great for autocross.....the limited slip requires a lot of maintenance to keep it working properly......the Salisbury Diff was the same way but the ramps not the diff allowed you the control how much drive you got on both rear tires.....and finally we are using the Quaiffe diff in the KMP259 and it works the best as it allows the rear wheels to unlock and turn in at the appropriate moment.....then as you accelerate towards the apex, the rear wheel drive the vehicle but not so much to push you away from the apex.....by the time you push the throttle down to the floor the Quaiffe diff locks up and drives the vehicle past the apex to the exit of the turn.......even in a straight line the car will jump a bit to one side or another....but then it catches and pulls straight forward......it is better to drive smoothly around the corners......and the Quaiffe verses the open, Welded, LSD, or Salisbury is by far better then the others.

For those of you who might not remember (or were not alive then) the torque biasing diff was invented for F-1. It was the original intellectual property of a crafty Brit named Quaife. The differential took on his name and the Quaife design. The Quaife torque biasing diffs were only available from Quaife until his patent ran out. Today there are umpteen different firms that produce a "Quaife design" differential, the largest firm being Eaton.

The design uses a myriad of pinions and driving / driven gearing to do it's magic. As Morris has already said the torque biasing design works better than the alternatives available today.

Here is a link to the Eaton TruTrac website, click here => Eaton TruTrac where they describe their version of the differential. There is also a video under the Performance section of their web page that gives a better explanation and illustration of the technology.

As I suggested, there are many providers of the torque biasing differential available today. Probably the premier provider is a company named Wavetrac. They have actually done some additional design engineering to improve the operation of the differential. Eaton uses six pinions in the design of their unit and Wavetrac uses 12 pinions in addition to a very innovative patented design enhancement to address a special situation that only occurs on torque biased diffs, where there can be a loss of drive during zero or near-zero axle-load conditions. In addition to the stronger, enhanced design, Wavetrac is the only manufacturer that offers a transferrable lifetime warranty on their unit — no matter where you use it including on a race tracK. Here is the link to their site => Wavetrac Torque Biasing Diff

The Wavetrac units use 9310 nickel steel for the internals like Pro-Series 9" Ford ring and pinions. The cases are either forged steel or CNC manufactured billet steel. It is a very nice differential — with a transferrable lifetime warranty. The clarity in the wording of their warranty provides a level of comfort that warranty wording usually does not.

This is how they phrase it:

"Autotech Driveline warrants each new Wavetrac® Differential against defects in manufacture, material, workmanship, and wear-out when used in the vehicle application for which it was originally designed, on any motor vehicle, under any and all operating conditions, including racing, (emphasis mine) for as long as the original purchaser or any subsequent purchaser owns the differential."

Rather all inclusive ...


Ed

[t walgamuth]

I believe the Torsen may behave like the Quaife. I had the torsen I believe in my Miata. The fact that it was limited slip was never noticeable.

[patrickt]

Well, fortunately I've given up on making my car safer. It is what it is and I'm already older than I deserve to be.

[twobjshelbys]

Originally Posted by 1795

I... Formula Fords that I used in my race school,

They had those at the Bondurant schools. They were the funnest cars to drive, even better than the Cobra or Ford GT (but of course, not street legal).

[eschaider]

Originally Posted by patrickt

Well, fortunately I've given up on making my car safer. It is what it is and I'm already older than I deserve to be.

Not with the intent of wishing to initiate any sort of a 'dust up', I by and large tend to agree with you.


Ed

[cycleguy55]

Originally Posted by eschaider

For those of you who might not remember (or were not alive then) the torque biasing diff was invented for F-1. It was the original intellectual property of a crafty Brit named Quaife. The differential took on his name and the Quaife design. The Quaife torque biasing diffs were only available from Quaife until his patent ran out. Today there are umpteen different firms that produce a "Quaife design" differential, the largest firm being Eaton.

The design uses a myriad of pinions and driving / driven gearing to do it's magic. As Morris has already said the torque biasing design works better than the alternatives available today.

Here is a link to the Eaton TruTrac website, click here => Eaton TruTrac where they describe their version of the differential. There is also a video under the Performance section of their web page that gives a better explanation and illustration of the technology.

As I suggested, there are many providers of the torque biasing differential available today. Probably the premier provider is a company named Wavetrac. They have actually done some additional design engineering to improve the operation of the differential. Eaton uses six pinions in the design of their unit and Wavetrac uses 12 pinions in addition to a very innovative patented design enhancement to address a special situation that only occurs on torque biased diffs, where there can be a loss of drive during zero or near-zero axle-load conditions. In addition to the stronger, enhanced design, Wavetrac is the only manufacturer that offers a transferrable lifetime warranty on their unit — no matter where you use it including on a race tracK. Here is the link to their site => Wavetrac Torque Biasing Diff

The Wavetrac units use 9310 nickel steel for the internals like Pro-Series 9" Ford ring and pinions. The cases are either forged steel or CNC manufactured billet steel. It is a very nice differential — with a transferrable lifetime warranty. The clarity in the wording of their warranty provides a level of comfort that warranty wording usually does not.

This is how they phrase it:

"Autotech Driveline warrants each new Wavetrac® Differential against defects in manufacture, material, workmanship, and wear-out when used in the vehicle application for which it was originally designed, on any motor vehicle, under any and all operating conditions, including racing, (emphasis mine) for as long as the original purchaser or any subsequent purchaser owns the differential."

Rather all inclusive ...


Ed

I'm running the POWERTRAX® Grip Pro - one of the many helical gear, torque sensing / torque biasing differentials you noted above. Like Eaton's TruTrac, this is a six gear system and, while it doesn't have the Wavetrac innovations that deal with zero or near-zero traction for one drive wheel, I don't see that as a limitation in my application. No lifetime warranty, but mine has performed flawlessly since it was installed.

https://www.powertrax.com/product-in...action-system/

[eschaider]

Most important thing is that you like what you've got Brian.

It can't get much better than that.


Ed

[joyridin']

Originally Posted by cycleguy55

I'm running the POWERTRAX® Grip Pro - one of the many helical gear, torque sensing / torque biasing differentials you noted above. Like Eaton's TruTrac, this is a six gear system and, while it doesn't have the Wavetrac innovations that deal with zero or near-zero traction for one drive wheel, I don't see that as a limitation in my application. No lifetime warranty, but mine has performed flawlessly since it was installed.

https://www.powertrax.com/product-in...action-system/

Mine works great also. I have had it for about 3-4 years now. No chattering around a corner, no doing a 180, and will still lay rubber with both tires.

[hauss]

I have a limited slip bmw backdraft so that is what I can share with you .1st best advice I was ever given.Take your time get used to the car .No mater what rear end tires brakes engine or what ever. 2nd walk around your car look for loose broken or worn items.3rd find a safe place and try out it limits . Braking, cornering, acceleration.4th start a savings account just to spend on your cobra cause your going to need it. Hope this helps boys.