LSD - how much will this benefit me?

[Rob Furniss]

In a straight line, not to trip out.

I've got one from an auto sat here, not sure if I have the matching splines yet as this is one of the uncommon ones (27 is it?) and it's a viscous unit too.
Just wondering how much of a pain it is to fit and how much benefit i'm going to get from it, my Son bought it for his car then realised it wouldn't fit his manual and mine is an auto so it's just sitting in the garage.

If it will benefit me at the drag strip then I may take the plunge and rip the gearbox out to fit the lsd but I don't have a press or anything if I need to do any serious gearbox shenanigans to remove the stock diff and fit this I may struggle (I don't know what i'm doing with gearboxes).

[spetz]

Did the FTO come with viscous LSD units?
These lose their efficacy over time and at 20+ years old it may not be doing it's thing anymore.

I was under the impression that they were helical diffs though not viscous.

As for how much of a benefit, if you can drop your 60ft time by 0.1-.02 seconds with one then that should equate to about 0.3 seconds faster ET from what I understand

[getonit]

Single pegs open legs. That is all.

[bjk]

Did the FTO come with viscous LSD units?
These lose their efficacy over time and at 20+ years old it may not be doing it's thing anymore.

I was under the impression that they were helical diffs though not viscous.

As for how much of a benefit, if you can drop your 60ft time by 0.1-.02 seconds with one then that should equate to about 0.3 seconds faster ET from what I understand

IIRC, prefacelift models (including the COTY? I think) had viscous units, and then the GPvR and facelifts optioned with it had the helical.

If it is viscous, I think they're the ones with the uncommon 25 spline, so you'd have to check your shafts as well to see if they match. And like Spetz said, depends in what sort of operating condition the diff is in to begin with.

[Rob Furniss]

It's this one that I got from Flateric in the Netherlands http://ftoaustralia.com/v3/viewtopic.php?f=2&t=28505

25 spline viscous from a 4 speed auto, done 63K.
Mine is a 5 speed auto, does that matter or is it just down to number of splines on my inner shafts?

Thinking to just drop the gearbox and hand it and the lsd over to a gearbox specialist for them to fit - or is it super easy to switch the diffs over once I have the box out?

[Rob Furniss]

Been reading one of flateric's posts about his driveshaft sourcing woes and I think i'm going to be out of luck unless mitsi changed the 5 speed autos to use 25 spline stubby shafts (but why would they?).
Anyone happen to have 25 spline stubby inner cv's going spare?
What other options do I have, is it possible to get my inner cv's machined to match the lsd?
Will the lsd from the 4speed even fit in the 5speed box?

Buy a wavetrac?

[FTODreams]

You cant get a Wavetrac anymore. So you'd probably have to go with Quaife. Someone at Wavetrac Europe said they still have 1 or 2 in stock though. Haven't got a response back from him though.

Also my 2c. Don't bother with the viscous LSD, I've got a friend over here with one that was actually so worn that it was basically an open diff most of the time. But there is a night and day difference having an open diff compared to an LSD when you've got enough power.

[Rob Furniss]

Project for later on then.
Do quaife do an lsd for the 5 speed auto anyone know?

[Rob Furniss]

Just pulled one of the shafts as I needed to do the inner cv boot - 27 spline, bugger.

[spetz]

I thought the auto and manual diffs were the same?

[Bennoz]

Very different

[Rob Furniss]

Ben - even if I could find 25 spline stubby shafts, do you know if the 4speed auto lsd will fit in a 5speed auto box?
Can I get shafts / inner cups made or mine modified to fit?

[Bennoz]

I'm not 100% sure about 4spd to 5spd. I'd hazard a guess as to say they are the same centre, but may have a different crown wheel depending on the final drive (amount of teeth on the output shaft.)

The 27 spliner cups are larger in diametre that the 25s. I dare say fabrication would be prohibitively expensive.

I have heard recently that the 25 spline cups were more frequently used on earlier lancers, like the CB.

[Rob Furniss]

Interesting about the CB lancer, might have a look into that.

Get rid of the slush box, noooooo.

[bjk]

Time for a sequential.

[Rob Furniss]

Looks like you're right Ben, need to get further measurements though and find out if the spider mechanism the same?

CB Lancer 1992 driveshaft 25T.jpg (29.66 KiB) Viewed 1760 times

These are right ones

[Rob Furniss]

Looks like this one is different size though

CB Lancer 1992 driveshaft 25T different size.jpg (29.89 KiB) Viewed 1760 times

[Bennoz]

Can you buy just the inner cups? Then transplant the rest off an FTO...

[Rob Furniss]

Cups on their own seem to be just outers not inners, a gearbox/driveshaft shop may be able to source them though.

[Rob Furniss]

Looks like Galant GSR 1988 to 1992 also and the inner CV's are PBT85 from Protex
CC Lancer 1.5 SOHC carb 65kw also use PBT85 inner CV's.