4x4 LSD's, are they true LSD's

[PRIMRK]

Now the title may not make sense but bare with me with this...

I've currently got an F series diff from a Tarago with all the mounts to fit into my AE86 but have had a look round and found that an LSD to fit is going to set me back approx $1k.

With a lil bit of research into G series diffs I've found I can pick one up with an LSD (from a landcuriser or hilux I believe) for $750 and get the mounts done for $350-$400 if I supply an old 86 diff. So from a financial point of view its worth the extra couple hundred for a stronger diff and LSD.

BUT, while speaking to guys at the wreckers one of the guys said that the LSD in 4x4's are different to the sort I would be looking to used on the track/drifting. Was his statement true? If so how different is it?

[oldcorollas]

depends what sort of centre...

clutch type, torsen type, clunk type
maybe they were thinking of the Detroit type = inside wheel unlocks to spin faster, and suddenly locks under power?
or they were thinking of air operated lockers?

tru trac F series are not that expensive?


oh, and guys at wreckers say lots of things....

[PRIMRK]

lol they sure do! That's why I figure id ask here first.

I'm not sure what sort of LSD Toyota puts in them from factory...Any one here?

[e30-323ti]

I posted some info at the end of this thread.

[foamy]

Also keep in mind the F series diff is much lighter then the G series. If it's for the track you could just weld her up/ locker? (much cheaper option!)

[mullett]

F series=every diff ever fits. For a drift car on a budget, I'd either weld it, or use a maxxgrip rebuild kit inside an MA61 centre, the whole lot would set you back under $400.

-RM

[PRIMRK]

It's not really a budget build but still haven't got unlimited cash, car is getting engineered so welding is not an option.

I'm looking at the G series with factory from a value for money aspect, for a few hundred more I can get a stronger diff with an LSD, but what I don't understand is how this LSD would differ form the TRD or kaaz LSD that I would be installing into my F series diff.

[oldcorollas]

ramp rates, number of clutches, diameter of clutches, pre-load etc (and availability of changing each of those)

and WEIGHT...

[PRIMRK]

im not up to speed in what exactly these mean, are you able to describe how they will differ in driveability? do they take more to lock up? do they not completely lock up?

[Drew]

Hilux diff but 2wd, the wheel bearings are more suitable as is the stud pattern for available wheels.centre should be interchangable with 4wd.

4wd lsd is clutch type & generally piss weak in a 4wd hilux but you can shim it tighter which will most likely be enough in a ae86.

Aftermarket lockers are cheap from the US ,hilux diffs are popular so auto lockers(basically a 2way) are easy to come by as well as mini & full spools,detroits, air lockers.
if you want an aftermarket locker you use a factory open centre = cheaper inital purchase price

Forget cruiser diffs they are too big & heavy

Cheers Drew

[oldcorollas]

http://en.wikipedia.org/wiki/Limited_slip_differential
might help for a start.. look for cross-section pictures as well

[e30-323ti]

ramp rates, number of clutches, diameter of clutches, pre-load etc (and availability of changing each of those)

and WEIGHT...

im not up to speed in what exactly these mean, are you able to describe how they will differ in driveability? do they take more to lock up? do they not completely lock up?

The standard toyota LSD's use springs to load the clutches and limit the slip, this is a constant amount of pressure regardless of how much 'differential' axle speed/load is occuring.
So, pretty basic in other words. There is the Maxgrip stuff you can use to increase the load on the clutches with different shims & extra springs.

The 'performance' stuff eg TRD, Kazz, Cusco, ATS, etc... have 'ramped' plates that load the clutches at a determined rate in relation to differential axle speed/load (ie more load = more pressure = less slip), this load is generated by the spider gears trying to separate the plates via the ramps.
A 2-way has the ramps at the same angle, a 1.5way has a steeper angle on the decel ramp and a 1 way has no ramp on the decel.
There are also versions (Cusco MZ I think) that also use springs or bevel washers to create some initial pre-load/breakaway.
Some also have multiple sets of ramps (ie. 2 & 1.5 way in the same unit)

If you looked at the link I posted to the other thread on a similar topic, there is a pic of a BMW LSD in pieces.
Inparticular of the internal components, where you can clearly see the ramps (2-way with 45° ramps).
A common mod for racing with the BMW centre is to machine the housing to fit 4 plates & alter the ramps to 90/10


my 2c: Go for a F-series with a TRD/KAZZ centre over Stock G-series.
It is lighter (important in a light chassis) and has a performance based LSD

[mullett]

+rep for a good answer...I agree too, an F series is plenty strong enough, anything stronger and you're just sacrificing weight. If it's going to be a drift car, then I'd consider the diff to be the most important part!

-RM

[PRIMRK]

Sure that it will be strong enough?!? We will be getting near enough to 300rwkw and prob stick a shot of nitrous through for when we head down to the drags. I don't want to be constantly chasing parts.

[e30-323ti]

Info on Engine & Tyres ?? 3UZ? from your other thread?

A small but hypo engine isn't going to produce masses of torque and if you can't fit big meats then they aren't going to have masses of grip !?!?!

You could always develop a de-dion rear end using a *A70 G-series, keeps the unsprung weight down, you could retain the 4-link +panhard (or Watts) and build some rear camber into it.


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