Limited Slip Differential - Effect on Wheel Spin

[ajwan]

This is a question for all you gearheads.

With a helical LSD installed (eg. Quaife, Wavetrac etc.), when you make, say, a right handed (or left handed) turn on an intersection with wet pavement and you step on the gas, is the inside wheel spin COMPLETELY eliminated, or is the inside wheel still going to spin, albeit slower than with an open diff? Can anyone out there pitch in and answer this question?

Thanks for your input,

AJW

 

[ajwan]

Sorry I forgot to mention, but this question is for a FWD vehicle.

AJW

 

[d00df00d]

Originally Posted By: ajwan
This is a question for all you gearheads.

With a helical LSD installed (eg. Quaife, Wavetrac etc.), when you make, say, a right handed (or left handed) turn on an intersection with wet pavement and you step on the gas, is the inside wheel spin COMPLETELY eliminated, or is the inside wheel still going to spin, albeit slower than with an open diff? Can anyone out there pitch in and answer this question?

Wheel slip in general is reduced unless both wheels run out of traction, at which point (obviously) both will slip.

Technically inside-wheel slip can never be eliminated, but with a good LSD it will be reduced to the point that it doesn't matter.

 

[gofastman]

Originally Posted By: ajwan
This is a question for all you gearheads.

With a helical LSD installed (eg. Quaife, Wavetrac etc.), when you make, say, a right handed (or left handed) turn on an intersection with wet pavement and you step on the gas, is the inside wheel spin COMPLETELY eliminated, or is the inside wheel still going to spin, albeit slower than with an open diff? Can anyone out there pitch in and answer this question?

Thanks for your input,

AJW

there is no such thing as a limited slip helical differential. By definition a helical differential is torque biasing, not slip limiting, if that makes sense.

 

[Bryanccfshr]

The best explanation I have heard for a differential is that it offers as much torque to each wheel as the wheel with the least traction gets. (if it takes 10ft pounds to turn the free whell the wheel on good footing only gets 10ft pounds of torque)

A limited slip acts like a brake on the wheel with the least traction increasing the overall torque available to the wheel with traction. This has its limitations as if one wheel has no traction the limited slip can not completely transfer the torque to the wheel with traction. The limitation is the friction the limited slip provides(wet clutch friction). If you want the wheel with traction to get maximum torque you need to get a locker. With a locker or a spool the only limitation to the torque to a whell is the traction of the wheel with the most traction on an axle. The engine cannot transfer any more torque than the traction can sustain.
For snow and sports cars limited slip is a nice traction aiding device. Many cars and suv's now have build in traction control that detects wheel spin and applies the brake to the wheel with the lack of traction, this in theory is the type of torque biasing action that the limited slip provides.