VLSD in snow

A somewhat ignorant question. I thought my 97 200sx SE-R with the factor Viscous LSD would be a beast in the snow. Instead the LSD appears to have no affect on my passenger wheel just smoking into oblivion when trying get get out of a parking spot in the snow. Why does my LSD not kick in at all? I know it is not a welded diff or a detroit locker, but I expected some benefit from the VLSD in the snow. Note 1) The brand new Falken 912s suck in the snow. 2) I am not buying snow tires because this is my last Chicago winter.

The viscous fluid in VLSDs tends to go bad after a while. If it's serviceable, you may need to flush out the old fluid and refill it.

VLSD doesn't "activate" without a certain torque level being hit. I forget the specifics, but it's nowhere near a posi or locker

If you chock the front wheels of a WRX with a 2x4 and lift the rear of the car, the VLSD center diff can't send enough power to the front to climb over the board. :(

Not sure about snow, as I sold it in the fall, but I know with my G35, the VLSD was poor at best. On pavement, it felt like an open diff in corners, then would lock mid corner, providing a very inconsistent feel. I felt like it needed some heat or something. I didn't feel like it would have worked that great in the snow.

I winter drove my S14(in Ontario,so its real winter driving)with top line snows with no problems,it had the factory vlsd as well.

I have long been curious about how well VLSDs work. I was a bit dissapointed to see that the diff comparo they did in the last issue only covered torsen and lockers.

As someone who is interested in possibly moving over to the STS2 class, I wonder if the VLSDs are advantagious...

That being said, I second ArtOfRuin. I have heard that they loose their effectivness over time if the fluid is not serviced...

i read that they don;t lock up in 0 traction situations. Something like there not being enough umph in the vlsd to totally lock up the wheel. dunno

Capt Slow wrote: That being said, I second ArtOfRuin. I have heard that they loose their effectivness over time if the fluid is not serviced...

I was under the impression that they are sealed and the fluid isn't serviceable???

I bet it depends on the differential.

IIRC the Viscous center differential of the subaru impresa is not terribly servicable.

However I belive the miata's VLSD did need to be serviced every once in a while. Though there are people (Where is Keith?) on this board who could answer this better than me..

I know nothing about the OP's 200Sx SE-R's diff though...

The VLSD in my '91 SE-R doesn't seem to do much on ice or wet roads for me either. The 240k miles on the clock might have something to do with it though.

Capt Slow wrote: I have long been curious about how well VLSDs work. I was a bit dissapointed to see that the diff comparo they did in the last issue only covered torsen and lockers. As someone who is interested in possibly moving over to the STS2 class, I wonder if the VLSDs are advantagious... That being said, I second ArtOfRuin. I have heard that they loose their effectivness over time if the fluid is not serviced...

I'd guess that some LSD is better than none for STS2, and that the servicability of a VLSD depends on the model. Hardcore competators may even get new ones if the old one is worn out and unservicable.

I plan on placing my FC RX-7 into STS2; it think it has a factory clutch-type LSD. I won't vouch for its effectiveness until I've driven it in anger or in the snow. The latter may occur as soon as tomorrow, since I have to bring it to a shop to have its oil pan gasket replaced.

time for a clutch type?

All my personal experience is with clutch type, but I've met a couple of rally competitors who swear that viscous LSD's are next to worthless in really, really slick stuff, and therefore they prefer clutch type.

ArtOfRuin,

Viscous or open diffs are the only ones allowed in STS2. Your Clutch type Diff isn't legal, Though most people wont complain...

until you start beating them

Capt Slow wrote: ArtOfRuin, Viscous or open diffs are the only ones allowed in STS2. Your Clutch type Diff isn't legal, Though most people wont complain... until you start beating them

That's not likely to happen. Besides my lack of experience, the FC3S RX-7 is the "musclecar" of Spec Civi... err, STS2.

My understanding is most viscous units (and in fact even torsens IIRC) act as open diffs in zero traction situations.