Lsd (limited Slip, Not Narcotics!)

[matt5cott]

Please can someone tell me what the deal is with LSD, does it replace traction control? ie can you boot it in lower gears, and it helps with traction?

Ive read into how it helps going round corners a little, but just wondering what you guys on here have to say about it :)

[longhallage]

normal differentials allow for wheel speeds to differ without restriction. The diferential is requires to allow for the different cornering radii of the wheels on an axle (inner shorter than outer). When you accelerate in a corner the weight transfer of the vehicle causes the inside wheel to spin its power away, reducing acceleration. If you can limit this spinning and transfer that energy to the outside wheel which has more grip you can maximise acceleration.

There are two types of LSD's. Mechanical and viscous.

Mechanical LSD's incorporate torsion sensitive clutch packs. If the sun wheel rotates at a speed different from the differential cage then the resistive force on the clutches increases in proportion to this speed difference. Hence the resistive effort depends upon the difference in driving torque.

Better is the viscous diff which varies it's braking effect as a function of the difference in road speed of the wheels. The action of this diff is more complex and depends on fluid shear rate (hence viscous). This, compared to the mechanical type, will give lower tyre wear, easier control and generally better driving feel. But, be careful in front wheel drive cars as they can catch you off guard when hot.

The whole point of a LSD is that it allows some wheel spin and splits torque to the wheel with greater traction. This is better than traction control as it does not reduce overall torque as long as one wheel is gripping. It also allows for oversteer in a RWD car as when both wheels lose traction the diff cannot cut power or brake wheels like electronic traction control.

If you want advice for your car it would be best to speak to a specialist. If your car has traction control fitting a LSD may confuse things. I IN NO WAY ADVISE THE DISABLING OF SAFETY FEATURES.

Nick

[TheNissanMan]

There were a number of imports which had LSD as standard (think the rev 3 turbo's) so no saftey device would have to be disconnected....

[matt5cott]

There were a number of imports which had LSD as standard (think the rev 3 turbo's) so no saftey device would have to be disconnected....

The one im getting has LSD as standard, I was just wondering how it shapes up to TCS :)

Thanks for the help so far :)

[TheNissanMan]

As long said LSD is in no way an alternative for a decent TCS but a means to get more power down onto the road. It also makes the car easier to control as you can judge the power been tranfered to the tarmac better (ie wheels not spinning).

At the end of the day who wants Traction Control on an MR2 it would take the fun out of the car :)

[longhallage]

Exactly Mr Haines. Rag it till it blows up :o

[TheNissanMan]

Not quite

But close enough