Torsen LSD not locking up

rs_simmo · Postby **rs_simmo** » Sun Jan 08, 2012 10:20 pm

Hey guys,
i bought a 1st gen torsen diff from MANIA and installed it in my NA6 when i broke my viscous 1.6 diff,
it all went in fine and drives correctly, after a few tests i would find it started spinning singles when i try to slide,

i drained my oil out of it and put like 120 weight nulon lsd synthetic in it in an attempt to make it lock up,
its definantly better, but i still cannot hold a slide without the inner wheel taking ALL the power mid corner with the throttle pinned,
sometimes doing a burnout it will swap from both tyres to one..

its so dangerous not knowing whether its going to spin one or two, short of getting another diff, i just want it to distribute the power properly

does anyone have any tips to fixing this problem?
will friction modifier work, (even though its not a clutch type like viscous)
or a certain oil that makes it hook up properly

cheers

RedMX · Postby **RedMX** » Sun Jan 08, 2012 11:10 pm

I have heard that the Torsen's somewhat have issues with un-weighting as that it actualy dose not fully lock up & is only 60-80% efficient @ lock up. If ya wanna drift get a spool or locker.

A lil more info on Diff's for the Mx-5 if you scroll down on that page.
>> http://www.mx5club.com.au/index.php?ID=8

Locutus · Postby **Locutus** » Mon Jan 09, 2012 1:52 pm

changing oils will only have a very small effect on the torque bias ratio of a torsen.

what suspension setup are you running? removing your rear sway bar, softening your rear suspension and/or increasing rear suspension travel should all help keep the inside wheel on the ground.

rs_simmo · Postby **rs_simmo** » Mon Jan 09, 2012 4:28 pm

Locutus wrote:changing oils will only have a very small effect on the torque bias ratio of a torsen.

what suspension setup are you running? removing your rear sway bar, softening your rear suspension and/or increasing rear suspension travel should all help keep the inside wheel on the ground.

Softening the rear?!
I'm on yellowspeed 8/6 w/max dampening + thicker sways
205 adrenalines on an 8 inch rim w/ -5 offset on the rear & 0 on the front

sailaholic · Postby **sailaholic** » Mon Jan 09, 2012 4:35 pm

Do you want to do mad skids, or have max corner grip. Set up is very different between them.

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Postby **NitroDann** » Mon Jan 09, 2012 4:38 pm

Are you trying to drift?Or get power down?

Dann

rs_simmo · Postby **rs_simmo** » Mon Jan 09, 2012 5:05 pm

Ok well coming around a slow/med speed corner at mid/high range second gear, try to accelerate out of the corner for best exit speed and it will just light up the inner on SOME occasions, unpredictable

sailaholic · Postby **sailaholic** » Mon Jan 09, 2012 5:38 pm

So you want grip.

Soften the rear sway bar if it's adjustable or fit the stock, one you may still have (?) If it is not adjustable.

Damping at max is probably not ideal but I don't know how the yellow speeds are valved.

Assuming it's the same valving as the higher spring rate units the are probably over damped as you have them set and not allowing the suspension to work over any bumps causing the rear to be unpredictable.

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deviant · Postby **deviant** » Mon Jan 09, 2012 11:27 pm

Yep go softer on the rear. Most of the fast circuit MX5's have the dampers wound almost full soft (depending on brand) and a stock rear anti-roll bar or often no bar at all. Front bar is normally something around 24mm and adjustable. Your spring rates are sensible for circuit work.

That set up will get you a neutral to understeer balance but you will have bags of grip.

project.r.racing · Postby **project.r.racing** » Tue Jan 10, 2012 9:26 am

with the stiff rear suspension. sounds like you might be lifting or at least releasing the pressure off the inside rear wheel, which a torsen does not like.

rs_simmo · Postby **rs_simmo** » Wed Jan 11, 2012 9:23 pm

deviant wrote:Yep go softer on the rear. Most of the fast circuit MX5's have the dampers wound almost full soft (depending on brand) and a stock rear anti-roll bar or often no bar at all. Front bar is normally something around 24mm and adjustable. Your spring rates are sensible for circuit work.

That set up will get you a neutral to understeer balance but you will have bags of grip.

yeah ive got a 24mmF and 18mmR sway bar setup,

i might stick the standard one back in the rear and see how that changes things

Postby **NitroDann** » Wed Jan 11, 2012 9:34 pm

A stiff rear bar will transfer a lot of load, leading to lifted wheels, if a torsen has one of the two wheels unloaded completely it will totally open up and you will go nowhere. This is why they dont like ripple strips.

dann

rs_simmo · Postby **rs_simmo** » Tue Jan 24, 2012 7:16 am

I found the problem- I paid for a torsen diff from mx5 mania and they gave me
An open which had type 1 torsen written on it.

Not happy. - will be taking back

Dweezle · Postby **Dweezle** » Tue Jan 24, 2012 7:53 am

Ahhh good old Mania......

Hellmun · Postby **Hellmun** » Tue Jan 24, 2012 6:48 pm

18mm is HUGE for a rear sway bar on an mx5, the 16mm whiteline is already too big for most people coupled with the 24mm front. If it has a normal amount of pre-load an 18mm will cause wheel lift on most round-abouts (my 16mm does setup just no preload) etc due to the camber of the road surface to promote drainage. A torsen will still spin an inside wheel whenever the inside wheel is unloaded, they need a little torque on both wheels for lock-up to occur so even if it was the right diff..that situation may still cause you grief.