So I got an LSD from traction concepts, yesterday I tore apart my trans to put it in. I’ve got it right down to putting it in, but it dose not seem to fit in the gears. I’m not sure what to do next. Anyone else run a traction concepts LSD? Would like to know if I’m missing something.
Traction Concepts is one of these "spring & plate" type friction devices, like the Phantom Grip. They're not LSD's. At best they're peg-leg burnout preventers.
Traction Concepts is one of these "spring & plate" type friction devices, like the Phantom Grip. They're not LSD's. At best they're peg-leg burnout preventers.
Sounds like the "positraction" differentials of old. They used a clutch to hook up the wheels to work together. Not sure that this is needed on a Fiero but it certainly can't hurt.
Sounds like the "positraction" differentials of old. They used a clutch to hook up the wheels to work together. Not sure that this is needed on a Fiero but it certainly can't hurt.
In an actual limited slip, the squeeze on the clutch pack is a function of the torque applied to the driveline... more torque in = more clamp load on the clutch pack. This is the way all "Salisbury" type diffs such as the LSD's used in older BMWs and Porsches works. These can have several hundred ftlbs of locking torque between the left and right axles.
A spring on metal plates inside the diff obviously has no such relationship. 80 ftlbs of preload torque on the bench is the same 80ftlbs it has when you roll into the throttle coming out of a tight turn. 80ftlbs is a tiny amount of preload for actual limited slip function.
As I said, at best it prevents a peg-leg burnout, but Fieros don't really do those anyway.
On my Ford Ranger (Ford 8.8 rear end), the clutch packs are located between the planet gears and the diff carrier.
The thrust load on the planet gears squeezes the clutch packs.
There is a small S-shaped spring in the middle; this loads the planet gears a bit against the diff carrier, even in the absence of torque from the propshaft. The spring probably results in about 80 lb*ft of friction torque. With the truck in gear, and both rear tires off the ground, I can almost fully torque the lug nuts, but not quite.
I don't know how all LSDs are done, but that's how it's implemented on my truck.
I could be wrong but very few newer factory LSD's use clutch type LSD's. They use the Torsen worm gear types. You can not use a clutch pack LSD on a front drive diff. The other LSD in common use today uses electrically operated clutch packs. These are the best because they work with the electronic controls to get better traction and cornering. The other common type is electronic braking control on an open diff. SBE and cheap.
------------------ 86 GT built 2.2 ecotec turbo rear SLA suspension QA1 coilovers on tube arms
[This message has been edited by wftb (edited 10-19-2020).]
There are still plenty of clutch packs used in RWD cars. C5, C6 & C7 Corvettes had them, for example, while an electronic diff was optional on the C7.
Yes, WWD (Wrong Wheel Drive) cars have to use helical style diffs in order to be able to turn. Some RWD cars have them too. I've heard of some Subarus having success on pavement by using a helical front, geared/viscous center and open rear in getting those nose heavy cars to turn.
I had an F150 that the differential went bad on while under warranty. The Ford performance book had a Torsen listed for my truck so since it all was getting done under warranty I had them put it in. Made a huge difference in snow and wet conditions. I just have never seen a need for one in a Fiero.
------------------ 86 GT built 2.2 ecotec turbo rear SLA suspension QA1 coilovers on tube arms
