Originally posted by lonestar
Hello Rick, nice to have someone here with some "inside" connections, or should I say someone who cares about their customer needs.
I have seen the thread about the interest for a Front Torsen and have a question about the T2 and T2R
The T2 mentioned C-clip rear applications and the T2R mentiioned it was ideally design for rear wheel drive SUV, pick-up and high performance applications. What is the difference between the T2 and the T2R? The T2R seems to have a PowerTrax design.
The T2R was also available in a Ford 8.8. Is there a T2 available for the rear? Are these for 31 spline axles? And how much?
Do you believe this is a better alternative to the PowerTrax? Why?
The T-2R and the T-2 are both helical gear differentials. In fact, if you looked at the gears alone, you'd see that they are very similar. Nothing Powertrax like here. The difference between the two is torque bias ratio. If you refer back to the T-2 SLA discussion, you'll see that the higher the TBR is, the greater the torque transfer ability of the differential is. The T-2 generally around 2:1, whereas the T-2R is about 4:1. It doesn't sound like much, but it is substantial.
In the example I gave in that post, 100 ft-lbs on the slipping side would transfer 200 ft-lbs (with a 2:1 TBR) to the good side, for a total of 300 to move the vehicle. With a T-2R, the diff would transfer 400 ft-lbs instead of 200, so the total that could reach the ground is 500 ft-lbs rather then 300. That's a 67% gain. We developed the T-2R initially for road race/autocross applications. We found after the fact that it lent itself nicely to desert racing, and Mr. MacCachren was happy to try it.
Long story short, the T-2R is high-bias version of the T-2. That's not to be confused, however, with the Torsen diff that comes in the Ranger FX4. That's a standard-bias T-2, but it also has a spring preload to help wheel in the air sorts of situations.
All told, there's 5 versions of an 8.8" diff that we currently make - both the T-2 and T-2R in 28T and 31T versions, and the FX4's unique T-2, which is 31T. They can go into either front or rear 8.8 applications, but I'd stay away from the FX4 unit in the front end, that should really only be used in the rear, for the reasons I described in the other post.
Better then a Powertrax? Well, again, I'll have to say it depends. It depends on what the vehicle configuration is, how its to be used, and what sort of terrain you normally deal with. Like I said in the other post, if you're rock crawler, then forget it. The Powertrax is better suited to that. If you're primarily a street driver that occasionally goes down logging roads, I'd think you'd be better served with the Torsen. If you're a rally nut like me, and enjoy going fast down loose roads, I'd think the Torsen is hands down better.
