Positraction is a generic term refering to a positive engagement of both rear tires (or front on FWD or AWD vehicles). LSD use a clutch to connect both axles but the clutches can and do slip. Torsen differentials sense which tire has the most traction and apply the torque to that tire although some report a one wheel burnout is possible with torsen/quaife type differentials.

Lockers use a ratcheting mechanism to "lock" both axles together but tend to be noisy.

An option appeared a number of years ago and has worked very well in the offroad truck racing arena. It is claimed to be quiet and uses interlocking teeth to lock both axles when high torque is applied. Otherwise it leaves the differential completely open and quiet. One of many very good features is it can be installed in our differentials WITHOUT removing it from the car!!!

The rear cover is removed, axles pulled out, spider gears removed and the locking mechanism installed. No need to worry about setting up the hypoid gears.

Current Toyota/Lexus application are limited to the 8" and 8.875" ring gear size truck differentials but I called and was told the cars should be supported within a month

Best of all the parts are less than $500.

Here are a couple links:

http://www.powertrax.com/noslip.htm

http://www.drivetrain.com/nosliplexus.html

 

Dang brady,
Looks like you're a torque convertor away from having a 13 second LS! Our stock GS4 has never been able to meet those numbers.

Keep us posted on the LSD for the Lex. I'd be interested for an application for the SC3.

 

Scott, thanks, I am pleased so far. But, as usual, performance is a never ending pursuit... not that I need to tell YOU that

I will post on the positraction news.

BTW, does anyone have an SC300/400 manual???

If so, check on the differential ring gear size.

 

Oh yeah, as far as 13s go... my traction is VERY limited as is. I am concerned that a TC would just make it harder to launch. I think the Powertrax PT with 3.62 gears would make it VERY close. Lowering the car should also be good for 1-2mph and maybe a tenth. Those mods PLUS a TC should get me 13 second bragging rights

 

These work with say a 1995 SC400?? I'm assuming they do. And do you project the performance gain to be comparable, equal, or better than an LSD?

 

bump on this; lets make them stay true to their word

 

I would suggest anyone interested email Powertrax directly. The information I posted was from a Powertrax dealer that called Powertrax while I was on hold. So, I guess first hand information is needed. I will email and I suggest anyone else do the same. The more response they get the faster this could happen.

 

Good tecnical article on how the system works

http://www.powertrax.com/nsop.htm

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