L.s.d

[124]

I thought I might add that in the Vlsd the V stands for viscous. Viscous diffs are basically a single open diff with some friction plates that heat up a fluid which then engages the other half but only if it gets hot enough. This system works well if used for an extended period of time or if warmed up before use (eg small burnout) but generally, when driving around normally it wont do anything if you try to drift straight up. So it is a cheap alternative to a proper lsd but its like anything you get what you pay for.

[wacomuk]

i cant see how this set up would be reliable as you are using 2 different types of joint on the same drive shaft. CV which isn't supposed to move and a lobro joint which is designed to move. i cant see the CV joint lasting very long

[30psi]

Originally Posted by wacomuk

i cant see how this set up would be reliable as you are using 2 different types of joint on the same drive shaft. CV which isn't supposed to move and a lobro joint which is designed to move. i cant see the CV joint lasting very long

They use the same type of CV joints, which is 3 spindle spider assembly type. Can't see how reliability is an issue, because the joints are working exactly as they were originally designed

[wacomuk]

Originally Posted by 30psi

They use the same type of CV joints, which is 3 spindle spider assembly type. Can't see how reliability is an issue, because the joints are working exactly as they were originally designed

doesnt the s13 diff use floting joints? (lobro joints)

[30psi]

Na, but I have seen that type on the fwd nissans though.

[Conkers]

Good point...

I suppose for the sort of people who bleed off the wastegate feed to up the boost, fit some neon lights, large rear wing and a shiny gearnob, then a viscous is certainly about as complicated as they want it to be.

But I have also seen a LOT of guys on here building 250-350bhp cars... and those guys would probably want something more serious than a shopping hack viscous diff.
I know the gpN cossies we ran in the WRC had viscous diffs, but they weren't much good either, my Integrale had a viscous centre diff and torsen rear, which made things interesting.... think terminal understeer until she came on boost and then a minimum 4 degree tail out... always kept me awake..

On my 6R4 we have plate diffs front and rear and a viscous centre.... the front is 4FF each side and rear is a 6FF each side and real tight at that... also drove McRaes subaru legacy (oooh about a thousand years ago) and he ran a solid rear diff, viscous centre, and the same 6FF spec as on my 6R4 at the front ! Needless to say, if you weren't committed, it did not want to go around corners.....

Looking forward to trying the welded diff on the s12, although mini roundabouts will be a pain..

Conkers.

[wacomuk]

Originally Posted by 30psi

Na, but I have seen that type on the fwd nissans though.

i bought a s13 LSD to fit to my s12 but decided not to use it as the diff had floating joints which would defiantly compromise the CV joints as the CV joints need constant velocity (CV) to work reliable

[30psi]

Conkers, you're missing my point though. Most people on here arent running big power, nor do they have a big wallet. There's probably 5 running over 250bhp, and very few have really shown an interest to get a better diff. Most here bought an S12 coz they were on a budget, and I can only assume they would like to keep it that way. Things need to be kept in perspective...

The S13 diff is a good upgrade over a standard diff. Yes, its no way near as good as a motorsport or clutch type item, but you need to appreciate that most people who own an S12 don't have deep pockets to afford such goodies. Even if a diff is robbed from a kingcab, it still won't be cheap. You also need to appreciate that most people on here don't have an engineering or motorsport background, and therefore won't have the skills and tools (like you) to setup a diff.

My mate had a welded diff in his S12, whilst brilliant for drifting, it created some alarming understeer at times, which don't help when the S12 front camber isnt too good for understeer. At no point have I said an S13 diff can be used for drifting though.

I will probably get an S15 torsen diff, but these are fetching some good money at the moment, but I'll stick with the S13 LSD that I swapped a used bleed valve, neon lights, a shiny gearnob and a rear wing for

[Draconis]

This is from Club S12 where GerryB did a short write up on what it took to get his S13 VLSD to work in the S12... which I'll be doing in the next 6 months.

I have an s13 VLSD centre in my longnose s12 type 4.11 R200. It bolted in fine after I swapped the s12 crownwheel on to it.

BUT for the RHS drive shaft I had to take the inner CV off and swap the s13 inner CV on to it and run the s13 RHS input shaft in the diff to operate the Viscous centre. Also had to cut off about 8mm off the end of the spline that goes into the diff of the LHS s12 driveshaft, so it didn't fowl on the viscous coupling.

After these mods was just a bolt up.

(I got the VLSD reshimmed also before fitting it, (extra shims) to make it real tight.)



http://www.club-s12.org/forums/index...howtopic=16318

[30psi]

The shimming thing doesn't have any impact on how the LSD works, it actually means the teeth of the pinion wheels bind together extra tight. Not good for wear and also the effect isn't smooth, its 'bumpy'.