Viscous Limited-Slip Differential (VLSD)

[jimmy4645]

Has anyone installed a Viscous Limited-Slip Differential (VLSD) on a G35 sedan?? I have an 06...

[RED_DET]

I have one from the factory. Did you get the "sport" model? If so, its a factory option.

[jimmy4645]

nope i didn't get the sport model. but thats something i would like to have. I just don't think it's possible since the cost would be high unless someone is parting there car out..

[g35beaver]

What is this anyway? It came with my 06 sedan with sports package but I have no idea.

[C-Kwik]

What is this anyway? It came with my 06 sedan with sports package but I have no idea.

Differentials distribute the power between drivewheels of all cars and allow each drivewheel to turn at different speeds as the inside and outside tires are going to need to travel a different distance in a turn. Most cars out there run an open differential that has virtually no resistance between the drivewheels. The problem with this is when you are trying to put power down and one wheel has less traction, the laws of physics dictates the power goes through the path of least resistance, which is the wheel with less traction. This is less than ideal and in many cases, it can be unsafe.

The other extreme would be to use a locked diff iin which the right and left drivewheel can not turn at different speeds. Locked diffs will transfer up to 100% of torque to the wheel with the most traction. If you were to take one wheel completely off the ground, the torque will stil go to the wheel on the ground. the downside here is when you take a turn in everyday driving, you will feel a wheel slip over and over as it has to release the bind that builds up between the two wheels. In some cases, some people have actually snapped axles. And in any racing other than drag racing, a locked diff will induce a lot of understeer as the loscked drivewheels will try to keepo the car going straight.

A limited slip differential is somewhere between these two. They essentially allow some level of slip (differing wheelspeeds), but limits it through various means. The most common use clutchpacks that limit slip through friction between many clutch discs. They generally have some variance based on if you are accelerating decelerating or at a constant speed. Another type is the Torsen which uses floating planetary gears that when loaded with torque push up against it's housing to create friction and provide some locking. This type is fairly expensive but quite effective as it act like an open diff when you are just cruising. Then ther are locking diffs which are generally only used on trucks, which fully lock by a manual or remote switch. The Viscous type used in the G35s and most Nissans that use a LSD basically use two plates which are maybe contoured or vaned that are very close together but do not touch each other. A viscous fluid is used inbetween and around the 2 plates and when the plates try to move in opposite directions, resists the movement. This generally provides the weakest locking effect, but is rather inexpensive and feels very transparent.

[sixxdeuce]

It would be a waste of time I think to swap a vlsd, viscous is garbage. If you want a diff just save up and get a 1.5way clutch type.

[jimmy4645]

where do you get a 1.5way clutch type and will it work on the sedans

[thekidzkid25]

thanx (C-Kwik) for clearing that up

[sixxdeuce]

where do you get a 1.5way clutch type and will it work on the sedans

it should be the same diff. Check around for Tomei, ATS and Cusco clutch types. Just dont get a 2-way, you probably wont like how it acts on decel.

[redtop91]

It would be a waste of time I think to swap a vlsd, viscous is garbage. If you want a diff just save up and get a 1.5way clutch type.

Viscous is more streetable. Not garbage by any stretch of the imagination. Especially when the alternative is an open differential.

[sixxdeuce]

it all depends on what you want. If you want reliable locking vlsd is not the diff for you. If you want slow reacting weak locking power then vlsd it is. I have alot of drive time on viscous, torsen and clutch type and nothing beats the feel and predictability of clutch type.

[shimman]

it all depends on what you want. If you want reliable locking vlsd is not the diff for you. If you want slow reacting weak locking power then vlsd it is. I have alot of drive time on viscous, torsen and clutch type and nothing beats the feel and predictability of clutch type.

vlsd should lock it reliably, but i think it did not provide you enough coupling for you to really feel it; besides, vlsd works in different way from torque sensing type; vlsd won't couple unless there is wheel speed difference, so you might feel unreliable as it won't pull the car at the corner. it is very soft diff

clutch type also has a problem and that is why most car manufacturers do not use as an oem because clutch type is more difficult to maintain like changing oil every 5k miles & required careful break-in to avoid angled clutch.

i haven't had a car with such a lsd, but my buddy used to have an after market clutch type lsd from toyota tdr branded one, and it did not last much; i think he replaced after 40k miles of use with oil change for every 5k miles he drove.

if you like to have harder coupling than vlsd, i would recommend helical type 1 way or 1.5 way, but unless you are driving at the track, it would be better to have sticky tires than installing lsd