Vlsd diff options?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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March 6, 2011 5:33 p.m. kevlarcorolla New Reader

I need to build a chain driven diff for a project,trying to find a cheap starting point.This will be used for a low grip surface so I think a vsld(that isn't completely knackered with age)will be better than a clutch lsd.I've used clutch pack before and the lack of grip across the diff has it acting like a welded and won't unlock. So I think the options are miata(what else on this board),S13/S14 240sx,possibly e30(not sure if they were vlsd).Anyone else have a suggestion on what to look for. The more common the better for axles etc.

Thanks for any ideas offered.
March 6, 2011 6:09 p.m. Tom Suddard SonDork

I don't have much to add, except that E30s use clutch-type diffs.
March 6, 2011 7:30 p.m. pres589 HalfDork

I bet they aren't cheap as dirt but a Miata + Torsen sounds better to me. But I have no real experience here, just ideas from what I've read. VSLD's sound pretty lame to be honest.
March 6, 2011 7:31 p.m. White_and_Nerdy Reader

You'll want to look for a 90-93 Miata diff if your heart is set on VLSD. 94+ are Torsen. You also won't pay the "drift tax" you might get hit for on 240SX parts. Common and cheap.
March 7, 2011 1:27 p.m. emodspitfire Reader

Hey,

Attached please find my research for Subie LSD's over the previous 10 years of production. (Couldn't figure out how to attach .xls file. Please send your email address and I will forward: rfsmith48@gmail.com)

The build code is the assembly plant ID for the diff. It is stamped in white characters about 1.5" tall, typically on the top of the diff.

The Alldata base that I used to generate this list is not clear about the later Torsen diffs, but the info in this list corresponds to what they call "mech" diffs.

Hope this helps.

Rog
March 7, 2011 4:15 p.m. Rustspecs13 Reader

the most common nissans that have VLSD's are the infinity J30 and Q45's. AFAIK every one has VLSD.

J30 axles have the same outer spline as 240sx hubs, and na Z32 hubs if that matters. Q45 axles are slightly bigger and stronger. Their outer splines are only compatable with Z32 TT and Q45 5 lug hubs.

~Alex
March 7, 2011 4:18 p.m. DaveEstey HalfDork

All Subaru outbacks had LSD's, the RS prior to 2002 did as well so there are a lot of options.
March 7, 2011 4:57 p.m. kevlarcorolla New Reader

Thanks,I'll look into the subaru thing.Torsen's are too much $$ for this plus this is for the ice and torsens aren't noted for being great if 1 wheel has grip and the other none. Emodspitfire I'll send you a pm now.
March 7, 2011 5:12 p.m. Type Q HalfDork

You didn't say how power you are planning to tranfer through this set up. I think ome of the 4wd ATV's on the market in the last few years have used VLSD's. I remember seeing one an FSAE team had gotten from the manufacturor to try out. I think it was for a high-end Polaris.
March 7, 2011 5:24 p.m. jpaturzo New Reader

This is where I gloat that I got a Torsen from an S2000 on eBay....for $6.

To the OP: you can adjust out some of the grip issues on ice by changing the torque bias ratio on the Torsen. This is usually adjusted by making a new shim stack out of bronze. I've never done it before, but this is what I have been told.
March 7, 2011 5:46 p.m. fasted58 New Reader

What about a Quaife? They make them for chain driven C and D Sports Racers... but they aren't viscous... and not cheap new. Maybe used?
March 7, 2011 5:49 p.m. kevlarcorolla New Reader

Jpaturzo-wanna double your money?

Think challenge type costing,I haven't seen any Quaife even close to being called cheap.

Type Q-the thing will weigh about 1500lbs and have about 160hp so I'm not sure if a quad diff will survive long.
March 7, 2011 6:11 p.m. doc_speeder Reader

All the 6 spd G35's have them too.
March 7, 2011 7:36 p.m. NGTD HalfDork

DaveEstey wrote:

All Subaru outbacks had LSD's, the RS prior to 2002 did as well so there are a lot of options.

My 97 Outback doesn't have one.