question on VLSD
question on VLSD
I've never driven a car with limited slip differential. Sounds like a great feature, but are there negatives? Does the stock VLSD engage/disengage in a proportional manner, or it's more like ON/OFF? thanks.
Re: question on VLSD (turn6)
The VLSD utlizes clutch plates that are lubricated with gear oil. When the gear oil shears the clutches slip allowing the wheels to rotate at different speeds. The amount of slip is proportionate to the difference between the inner and outer wheel speeed in a turn.
There are no drawbacks. The VLSD is seemless in it's function. You will never know it's there unlessyo uhave driven a car without the VLSD and get into a car with one.
There are no drawbacks. The VLSD is seemless in it's function. You will never know it's there unlessyo uhave driven a car without the VLSD and get into a car with one.
Re: question on VLSD (turn6)
its not really gear oil its Viscous goo and it gets thicker when at high temps or strain.The discs are not and never physically touch in a vlsd. When the goo heats up and thickens it connects the discs together.
Re: question on VLSD (R350Zz33)
The VLSD in the Z has 80W90 gear oil in it and nothing else.
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C-Kwik
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Re: question on VLSD (JETPILOT)
The gear oil used in the pumpkin is only there to lubricate the spider gears and the ring and pinion gear. The gear oil does not affect the viscous coupling. The viscous coupling in the differential is sealed and uses a much much thicker silicone based fluid. The VLSD and open diff Nissan uses in the R200 are not much different. The VLSD simply has a viscous coupling attaching 2 of the internal spider gears together. The operation you describe is what happens in a LSD that uses clutch packs. The VLSD uses no clutches and the discs within make no contact, ever.
To the OP, the VLSD is quite transparent. This is because the resistance is based on a fluid so the slip/lock mechanism is gradual (relatively). By contrast, clutch LSDs will generally remain locked and breakaway once it hits the the threshold for slip. Helical LSDs need to load up slightly before the locking occurs so there is an ever so slight delay in operation. I occassionally heard some noises out of one of these as it locked up. Clutch types can make noises during operation as well. The Really big disadvantage for a VLSD is that the lock-up is quite mild. Much better than an open diff, but don't expect much help if you get stuck in the mud with it. In fact, I had parked on a steep driveway that was caked with dry mud. One tire had some traction, but the other had none. I had a very difficult time getting the car up the driveway as it kept spinning only one wheel. But this isn't a situation most sports car drivers will be contending with on a race track or in spirited driving so its not a huge problem. But the resistance to spli is lower than you might find out of a mechanical or helical diff.
To the OP, the VLSD is quite transparent. This is because the resistance is based on a fluid so the slip/lock mechanism is gradual (relatively). By contrast, clutch LSDs will generally remain locked and breakaway once it hits the the threshold for slip. Helical LSDs need to load up slightly before the locking occurs so there is an ever so slight delay in operation. I occassionally heard some noises out of one of these as it locked up. Clutch types can make noises during operation as well. The Really big disadvantage for a VLSD is that the lock-up is quite mild. Much better than an open diff, but don't expect much help if you get stuck in the mud with it. In fact, I had parked on a steep driveway that was caked with dry mud. One tire had some traction, but the other had none. I had a very difficult time getting the car up the driveway as it kept spinning only one wheel. But this isn't a situation most sports car drivers will be contending with on a race track or in spirited driving so its not a huge problem. But the resistance to spli is lower than you might find out of a mechanical or helical diff.
Re: question on VLSD (C-Kwik)
Viscous Limited Slip Differential (VLSD)
A viscous differential works by heating a thick fluid, making it expand. The diff has 2 plates close together (one for each axle), similar to a clutch type diff, but they never touch each other. When the wheels spin in opposite directions the fluid between the plates is heated up and expands, locking the plates together. As you can imagine its not a very efficient lock, but the smooth power transfer makes it the most streetable limited slip differential.
A viscous differential works by heating a thick fluid, making it expand. The diff has 2 plates close together (one for each axle), similar to a clutch type diff, but they never touch each other. When the wheels spin in opposite directions the fluid between the plates is heated up and expands, locking the plates together. As you can imagine its not a very efficient lock, but the smooth power transfer makes it the most streetable limited slip differential.