Differentials: T2R vs. True Trac

[tomshep]

Gents,

I need some input here. Currently, my car is running a detroit locker rear differential. It is a C-Locker and after some research is designed more for circle track use. The problem with it is it has play and I believe that is contributing to the breaking of 3rd gear in my trannys. When I am accelerating out of a corner the differential free spins for 90*-180* before locking up. The drivetrain is absorbing that engagement and 3rd is the weak point.

Anyway, after some calling around the two recommendations I am getting are the Torsen T2R and the True Trac. Both operate under the same design with minimal play. One item that has been stated and I don't quite understand this is the TT has 3 pinion gears or worm gears for more strength vs. 2 in the T2R. Anyone have any comment on that?

I know a bunch of you are running T2Rs. Any comments--good or bad?

Is anyone running or have any experience with the True Trac?

Thanks,

Tom

 

[ac427cobra]

Tom:

IMHO, T2R. End of story.

 

[bssmith1220]

I ran a true-trac in a stroked 95 road race car. It worked great for me, drove it on the street and on the track. Held up for 30k long hard miles before I sold the car.

 

[Terry Moenich]

The T2R has a 3.5 bias and the new design Tru-Trac has a just under 3.0 bias.

That being said, if you are not lifting a rear tire off the ground on turns, the new Tru-tracs seem to be holding up fine.

All problems I have heard of are in IRS cars that are lifting tires, the inside tire seems to spin then. I have installed Tru Trac's in several cars all perform great.

I have sold one to a guy with an IRS who had issues of the spinning tire, when it was removed from the car, the unit was fine. It was in the set up of the suspension according to Trac Tech. The T2R seems more forgiving in this example.

I sell both.

 

[ShelbyGuy]

boy racer ships with a trac-tech c-locker

 

[93SVTCobra]

Who is telling you that the T2R only has two gears?

That is a regular T2 and it has just as many gears as the T2R does.

I've sold quite a few T2R's and have never heard a bad thing about them except that the customers wish they would have bought them sooner!

 

[pipeliner]

The T2R has a 3.5 bias and the new design Tru-Trac has a just under 3.0 bias.

That being said, if you are not lifting a rear tire off the ground on turns, the new Tru-tracs seem to be holding up fine.

All problems I have heard of are in IRS cars that are lifting tires, the inside tire seems to spin then. I have installed Tru Trac's in several cars all perform great.

I have sold one to a guy with an IRS who had issues of the spinning tire, when it was removed from the car, the unit was fine. It was in the set up of the suspension according to Trac Tech. The T2R seems more forgiving in this example.

I sell both.

Its true . I have had nothing but problems with my True TRAC and the irs spinning the tire, but it also workswell on my straight axle car.

 

[racebronco2]

i have the tr2 and it works great, i used to have the detroit c-locker in my race truck, to prevent the harsh ingaugement in mid turn i used to match the revs and ease into the throttle ...never had a problem with the locker or the t-5 tranny for over 5 years .... the tr2 is so much more forgiving mid turn shifting, braking etc ... i remember the first time or two that i shifted mid turn, i thought i was going to do a 180*

 

[tomshep]

The T2R has a 3.5 bias and the new design Tru-Trac has a just under 3.0 bias.

Terry,

Please explain "bias". Is this some sort of multiplaction factor? Is more usually considered better?

Thanks, Tom

 

[Terry Moenich]

Bias is hard to explain here, maybe the engineer types can help here. My explanation would be if traction differs from side to side more than the bias, the tire with the least traction will spin.

Here is a link to the Tru-Trac

http://www.tractech.com/docs/DetroitTruetrac04.pdf

If it is going in an IRS car, I'd go Torsen T2R

As far a s a Detroit locker goes, I ran one at Road America..ONCE!!

I downshifter going into 5 one side unload and I had a Windshield full of concrete, luckily I lifted and got it under control. The only damage was a large stain in my pants!!

Lockers are for Drag Racers. They were used in the Glory days of Trans Am racing, but they had no alternative then.

 

[93 COBRA]

Lockers are for Drag Racers. They were used in the Glory days of Trans Am racing, but they had no alternative then.

I believe they are still used in Trans-Am, slightly modified from what is sold to the general public. We used to supply Lockers directly to the Roush Trans-Am team with the "hold-out" rings removed (locker responds quicker but is constantly ratcheting throughout turn) and a variety of different rate springs to adjust the amount of preload.

ex-Tractech engineer

 

[13 Cobra Toy]

No problems here with the true trac in my IRS car.... :shrug:
Five track event and 466 tq to the rear wheels and it's never missed a beat.

 

[JoeJ]

Guys,

I have run the Torsen T2R in my 2000 Cobra R since shortly after I bought it in 2000. I currently have approx 12000 track miles on the R and the Torsen has never looked back. I highly recommend it.

 

[ac427cobra]

Guys,

I have run the Torsen T2R in my 2000 Cobra R since shortly after I bought it in 2000. I currently have approx 12000 track miles on the R and the Torsen has never looked back. I highly recommend it.

Joe:

Just out of curiosity, what lube do you run and how often do you change it?

Thanks,

Bruce
:thumbsup: :coolman: :beer:

 

[Terry Moenich]

For the Ex Tractach engineer, what your take on the differences..

Thanks

 

[JoeJ]

Bruce,

I run Royal Purple Max Gear 75W140 and I change it after 4 track weekends. It seems to stand up really good. However, it is not cheap. I also run Royal Purple R51 Racing Oil, also very expensive, but I figure that my engine would be hard to replace. I change it after two weekends on the track. I also understand that Redline Racing oil is good.

 

[SGL]

True Track (new design) here with approximately 5,000 miles and a few open track events. no diff cooler too. Per recommendation of DTS, I use good'ole 85W140 dino oil. Runs like a champ with street tires.

 

[Andy M]

T2R on mine as well. At least 3000 track miles on it and it is sensational!! :rockon: :beer:

 

[pipeliner]

No problems here with the true trac in my IRS car.... :shrug:
Five track event and 466 tq to the rear wheels and it's never missed a beat.

Have you tried a AutoX with it? Tell me how it does with real tight turns.

I have been through my rear suspension manytimes to try to figure out the problem. I have also had many friends that are excellent suspension people and we are still unable to figure out why it dosnt work with that little bit of unloading.

In tight turns on a corse the car plants like you wouldnt believe its just spins one tire like a madman intill the other can catch up.

 

[13 Cobra Toy]

Have you tried a AutoX with it? Tell me how it does with real tight turns.

I have been through my rear suspension manytimes to try to figure out the problem. I have also had many friends that are excellent suspension people and we are still unable to figure out why it dosnt work with that little bit of unloading.

In tight turns on a corse the car plants like you wouldnt believe its just spins one tire like a madman intill the other can catch up.

Pipeliner,

Sorry I'm not much of an autoXer...

My understanding is any torsen style diff needs some resistance on the other wheel to make everything transfer power to the wheel that is not slipping. With that said, if your wheel is coming off the ground then it's not able to transfer the power to the wheel that has grip.

The Torsen T2R has a pre-loaded invex gear set to give it some resistance to the wheel in the air and help transfer power to the wheel that has traction.

One of two things may help...softer suspension setup or maybe Torsen T2R :shrug:

:beer: