Torsen T2R Spinning Inside Tire

[Dubstep Shep]

Shep. You're doing it again, man. Haha you asked and answered your own question.





You in Houston yet?

Hahaha just trying to confirm that I'm following everything correctly!

Not yet. Talked to a guy today about getting an apartment. Looking like late June for a move in date.

The Boss has its own version of T2, which is different from a regular T2. Higher bias ratio (2.7?) and twice as expensive. The T2R is different from both of those.

Didn't know that about the Boss having a different T-2.

So OP, does this car have the factory Boss T-2 or the T-2R diff?

 

[chilema]

Just an FYI, the T2R is NOT preloaded... it says right on their webpage that it isn't.

The Boss units aren't but I'm pretty sure the FR500S units with the 4.0 bias ratio are, but don't quote me on it haha.

This one, I think:

http://www.americanmuscle.com/ford-31spline-88-fr500-diff.html

Ideally something like an OS Giken would be awesome, but last I checked they might not have one for the 8.8 just the 9 inch. Wavetrac could be an interesting option too.

But hey, local CP legend Mike Maier would say locker or nothin' and I'm beginning to believe him more and more.

http://www.lethalperformance.com/detroit-locker-8-8-31-spline-differential.html

 

[Whiskey11]

The Boss units aren't but I'm pretty sure the FR500S units with the 4.0 bias ratio are, but don't quote me on it haha.

This one, I think:

http://www.americanmuscle.com/ford-31spline-88-fr500-diff.html

Ideally something like an OS Giken would be awesome, but last I checked they might not have one for the 8.8 just the 9 inch. Wavetrac could be an interesting option too.

But hey, local CP legend Mike Maier would say locker or nothin' and I'm beginning to believe him more and more.

http://www.lethalperformance.com/detroit-locker-8-8-31-spline-differential.html

Nope, the T2R with the 4:1 bias ratio is NOT preloaded:
http://www.torsen.com/products/T-2R.htm

Under the "exploded" diagram (with preload springs) it says:

Note - Preload is NOT available. Picture is used as a representation of the internal components.

If you unload a T2R it WILL fry the inside tire like it wasn't there. The T2R does allow for a greater difference in wheel speed between the inside and outside before it spins up the inside but if you get it light enough, it will still fry that tire.

The only Gear diffs I know with preload are the Wavetrac (which I've written off as fragile junk at this point) and the DPI Black Gold diffs with half, 3/4 and full tight which they no longer make it appears.

 

[2008 V6]

A buddy's Boss 302 with T2R is running Pirelli P-Zeros and has the inside wheel spinning where he can barely power out of turns during autocross. I have the same issue with my stock diff:

Notice it at 0:42-0:46 - https://www.youtube.com/watch?v=WVpd_W4teQk

Notice it at 0:22-0:25 - https://www.youtube.com/watch?v=tljklbWqvYw

Have any of your guys running slicks run into the same problems with a T2R? He is looking to potentially upgrade his Torsen and I am looking to upgrade my stock diff. I will not go with Torsen if people are experiencing similar issues.

I also have diff fluid leaking onto my LR wheel, which I notice when swapping wheels out after an event.

Eaton is 3:1 bias ratio – worm drive diff.
If one tire losses contact with the ground or as minimum contact when too much pedal is applied / hp, it will work like an open diff - like a Torsen. Check out youtube for a working schematic of the Torsens genius. Wavetrac (?) Don’t know the spelling and too lazy to look up - alleviated this problem by adding clutches. They are still trying to figure out a design - make is more reliable.

 

[chilema]

Nope, the T2R with the 4:1 bias ratio is NOT preloaded:
http://www.torsen.com/products/T-2R.htm

Under the "exploded" diagram (with preload springs) it says:


If you unload a T2R it WILL fry the inside tire like it wasn't there. The T2R does allow for a greater difference in wheel speed between the inside and outside before it spins up the inside but if you get it light enough, it will still fry that tire.

The only Gear diffs I know with preload are the Wavetrac (which I've written off as fragile junk at this point) and the DPI Black Gold diffs with half, 3/4 and full tight which they no longer make it appears.

I stand corrected. Looks like the notion of a preloaded T2R of any kind may be a remnant of the past, and for GM guys only. I know of at least one local GM guy who has clutches in his T2R but the car was put together like 10 years ago. At this point some T2R's might at most have preload springs in them but are just as vulnerable to lifting a wheel and spinning the inside tire.

From the sound of it OP's car is a daily driver or at least street-driven, otherwise a Detroit Locker might really be the hot ticket. I'm kind of in the same boat, and the Truetrac is just not quite doing it for me on R-comps. We will experiment with the Whiteline rear bar settings, but I have a sneaking suspicion the car won't like anything other than full soft or completely detached. Upping the spring rates and setting the front bar stiffer will probably help as well.

 

[Dubstep Shep]

So what is even the point of the clutches?

From my understanding, it's possible to eliminate the "open diff" condition by applying some sort of resistance to the side without traction. For instance you can apply the brakes to the wheel that's spinning and it will transfer power back to the wheel with traction.

 

[csamsh]

So what is even the point of the clutches?

From my understanding, it's possible to eliminate the "open diff" condition by applying some sort of resistance to the side without traction. For instance you can apply the brakes to the wheel that's spinning and it will transfer power back to the wheel with traction.

That's how a lot of cars with an "electronic limited slip" do it

 

[Dubstep Shep]

That's how a lot of cars with an "electronic limited slip" do it

Exactly. Using a computer controlled ABS module, it would be pretty easy to selectively apply the brakes and regain traction.

My question is, are the clutches in the T-2R designed for that purpose? It would seem likely.

 

[Whiskey11]

So what is even the point of the clutches?

From my understanding, it's possible to eliminate the "open diff" condition by applying some sort of resistance to the side without traction. For instance you can apply the brakes to the wheel that's spinning and it will transfer power back to the wheel with traction.

Yes, you can. In fact the first generation HWMMV had Torsens front and rear and you had to apply the brakes and gas together if you had a wheel airborne. The idea is to eliminate that "open diff" condition without having the driver make the corrective measure since generally applying brakes mid corner while trying to accelerate is counter intuitive and difficult to do.

Personally, if you have a Torsen or other gear diff and are seeing inside wheel spin then I would spend a lot of time focusing on car setup and run less bar and more spring out back or more spring up front to keep more weight on that inside rear.

 

[csamsh]

Or left-foot brake better

 

[Dubstep Shep]

Hahaha both possibilities.

I wonder if the purpose of those clutches was to provide a small measure of resistance when the axles are spinning at different speeds, and thus hopefully cure the open wheel issue. If they aren't preloaded I'm not sure what other purpose they could serve.

 

[Whiskey11]

Or left-foot brake better

Left foot braking while accelerating is a horrible idea... fix the suspension setup and power out of the corner correctly.

Hahaha both possibilities.

I wonder if the purpose of those clutches was to provide a small measure of resistance when the axles are spinning at different speeds, and thus hopefully cure the open wheel issue. If they aren't preloaded I'm not sure what other purpose they could serve.

Higher bias ratio with the clutch packs. My understanding is that the difference between the T2 and the T2R is that the T2R has a different set of metal "wear pucks" that are more aggressively textured and sit in the pockets for the worm gears and provide the higher bias ratio. That does eventually wear out.

No idea if that is true though as I haven't had a T2R in front of me, let alone apart and in front of me.

 

[csamsh]

Left foot braking while accelerating is a horrible idea... fix the suspension setup and power out of the corner correctly.

The whole idea of left-foot braking is to be on the gas and brake at the same time though

 

[2008 V6]

I wonder if the purpose of those clutches was to provide a small measure of resistance when the axles are spinning at different speeds, and thus hopefully cure the open wheel issue. If they aren't preloaded I'm not sure what other purpose they could serve.

- Yes -

 

[Sky Render]

The TrueTrac has a 3.5:1 bias ratio, according to Eaton.

Any gear-type diff will spin the inside wheel if you lift it off the ground.

Sent from my toilet using Tapatalk

 

[2008 V6]

The TrueTrac has a 3.5:1 bias ratio, according to Eaton.

Any gear-type diff will spin the inside wheel if you lift it off the ground.

Sent from my toilet using Tapatalk

I spoke with Eaton also they told me 3:00 – 1:00. Wouldn’t it me nice to get a correct answer some time! When I made the decision to purchase my Torsen 2.7 to one – That was driven by my cost. I researched Eaton, Wavetrac & Torsen. I spent over a ½ an hour on the phone with one of Torsen’s engineers - I was impressed SMART GUY. When I called Eaton, I spoke to a customer rep for about 5 minutes – wasn’t impressed but he stated more than once a 3.0 Bias ratio so I could be wrong. I haven’t looked for any printed literature because I bought the 2.7 driven by cost and the Engineer I spoke with.

 

[Dubstep Shep]

Interesting.... I thought the bias ratio was caused by the ratios in the gears. I suppose added resistance would increase a normal bias ratio though.

 

[Sky Render]

The bias ratio can also vary based on the viscosity of the gear oil. Friction modifier actually decreases the bias ratio on a gear-type LSD, which is one of the reasons you shouldn't put it in.

 

[Sky Render]

3.5:1 bias ratio, on Eaton's website:

http://www.eaton.com/Eaton/ProductsServices/Automotive/DifferentialsLockingDifferentials/PCT_317264

 

[Whiskey11]

The whole idea of left-foot braking is to be on the gas and brake at the same time though

You generally aren't left foot braking when you are trying to accelerate out of a corner where most of your inside wheel spin would occur on a Torsen diff. Just saying!