STaSIS diff

[hiloran]

Linked timing chart worked for me. If timing is wrong torsen did not turn.
Washers I used were AS3552 (Old torsen). just relpaced the bronze and needle bearings at the ends. two piece and new B5 E and F torsens use AS3047.

https://www.dropbox.com/sh/h6jnswfiq16d4m8/AAAMFE5-WqWTBcVc4OPEC-1Xa?dl=0

[diesel des]

Yes to both questions

[andy10v]

I have found a fella in the states that supplies steel washers to replace the Teflon or brass covered center washes in the center of the stack.

Ethan Creeger?

[andy10v]

If they are T1 does this apply to our diffs?

http://torsen.info/fsae/fsaefaq.htm

14. What does “timing the differential” mean? The timing refers to the orientation of the spur gear teeth on the ends of the element gears in relation to the helical teeth. The differential must be timed properly - that is, the gears must be orientated together properly to operate correctly.


15. How do I time the differential? The timing information is given in the Timing Chart in the lower left-hand corner of the M021-DHU print. Windows 1, 2, and 3 refer to the element gear windows, viewed form the top, in the counterclockwise direction. Install the bottom gears first, around the side gears. Start with each gear’s timing mark straight upward, on the left side of the gear. Rotate the timing mark toward the outside of the differential the number of teeth given in the Timing Chart for each gear. Repeat for the top element gears. When completed successfully, the differential should roll (differentiate) freely.


16. What will happen if the differential is not timed properly? Proper timing is required for equal load sharing among all the gearing. It is possible to build the differential incorrectly, and have it still roll (with some difficulty). However, the internal loads will not be evenly balanced among the gears, and some will be severely overloaded. This will lead to eventual failure, often catastrophic.

19. Can the University Special be modified to increase performance? Yes, to some degree. Since performance (torque bias ratio or TBR) is a direct function of the unit’s internal resistance to differentiate, changing the resistance will change the TBR. Most of this resistance comes from the gear design itself, and cannot be altered. However, there are other frictional factors that can. One of these factors is the friction coefficient of the washers, which the side gears thrust against when torque is applied. We use a variety of different washer types to adjust the TBR. Higher friction washers include plain steel, steel with nickel plating or FNC heat treating, and hardened bronze. To reduce friction, we also use needle bearings as well as washers with a Teflon-based coating.

For the 012000, the torque bias ratio is about 2.6:1 in drive (throttle-on) and 4:1 in coast mode (drop-throttle/reverse) if the differential is mounted in the car with the large input spline toward the left (normally considered driver’s side). Switching the thrust washers that are situated between the side gears and differential housing end for end will reverse the torque bias ratio for drive and coast modes. This gives a drive mode increase in TBR that is normally favorable for this type of car. If the large spline is on the right when installed in the car, then the washers are already in the correct location to do this.

For the M021-DHU, the needle bearings between the side gears and housing/cap can be replaced with steel washers of the same dimensions. Another variation would be to replace only the bearing on the left side of the differential (as installed in the car) with a steel washer. This may offer a better balance of performance between throttle on and off.

Using less viscous oil will also raise TBR. A more viscous fluid will lower it. If you are changing the oil, be sure that you still use a GL-5 specification lubricant.

[diesel des]

I have done a bit more research and stripped some of the diffs down. You need a later diff as the early ones have a different shim stack and won't adapt easily or in the same way. Bother early and late 01e centre diffs are t1 torsens. They are not t2. T2 have gears that run in a different way to ours. So calling them t1 and t2 is wrong. Just early and late t1.

Anyhow if you put it together with the gears in a different position the diff is tight to turn. But this is only distributing the torque unevenly within the gears in the diff and will kill it quickly. Before it dies it may well be doing interesting things to the bias. It does seem to be the friction of these washers that affect how the gears react to each other. The gears need timing up as factory.

I have found a fella in the states that supplies steel washers to replace the Teflon or brass covered center washes in the center of the stack. These are only used for the friction property. There are steel shims in other positions to trim each diffs clearances. Both late diffs I looked at had the same dimensions for the friction washers. I found a source in the USA for the high friction washers and have ordered 3 sets. I will do both the later diffs I have and see how I get on.

Cheers des.

[butchone]

I have asked gripper they will only plate them, an cant split torque

[terrybullwon]

Gripper

[butchone]

I have one of the strasis 01e Modded center diffs in the rally car , have had it for 5 or 6 years i am 100% sure it gives more rear biass and helps to reduce understeer [ but ive always got the hand brake to un -settle the rear end if req ] i dont think the average driver on the road would notice the difference wth a modded diff, i also feel for me i would prefer a permanant 60/rear 40front plated center diff , this way i could be certain the car would do the same every time, but i wouldnt be able to use hand brake unless it had an expensive handbrake release system [more to go wrong]

any idea were the 60/40 plated diff can be bought/modified?

[diesel des]

Ahhhhh I see. Is that what stasis do too? Aprox how much for the work?

[JP]

Hahaha. Nope nothing to do with shims. It's to do with altering the gear timing to create different loading behaviour. Get the timing wrong and it'll either not go back together or **** itself.

[diesel des]

Jp Isn't it just brass shims replaced with steel ones to give the higher friction? Then timed up as was? I have a spare diff I could send you. Give me an idea of price. Cheers des.

[JP]

Yes and no. Can do them however i need mine out of my box to copy as the timing instructions have gotten lost over the years.
If enough demand I'll pull my diff out my box to copy and rewrite the instructions.

[diesel des]

Jp are you still doing these torsen mods?

[A1quattro]

I have one of the strasis 01e Modded center diffs in the rally car , have had it for 5 or 6 years i am 100% sure it gives more rear biass and helps to reduce understeer [ but ive always got the hand brake to un -settle the rear end if req ] i dont think the average driver on the road would notice the difference wth a modded diff, i also feel for me i would prefer a permanant 60/rear 40front plated center diff , this way i could be certain the car would do the same every time, but i wouldnt be able to use hand brake unless it had an expensive handbrake release system [more to go wrong]

[JP]

Yes can still do them. Been so busy forgot about this thread. If doing track stuff definitely a plus. If doing drag racing I would say stock setup is better.