I have a 1995 sti type RA. on the centre diff adjuster numbering the settings from 1-6(1 being locked,6 being bottom green)

1.what would be the best setting for normal driving?

2.why are the top 4 (1 to 4) settings orange & the bottom 2 (5 & 6) green? & is it alright to leave the centre diff on one of the orange settings?

3. is it alright to change the setting whilst on the move or should you stop before changing?

4.when i use the car in any of the orange settings i get a loud clicking & the car jolts every revolution of the wheel what could this be & is it expensive?

Thanks for any help

Mike Hall

For normal driving in Dry conditions I leave the diff in the free position ie full back and the guage on the bottom green marker.

If it is wet and the tailend of the car is starting to get a little out of control then I would move the control forward one or two marks up the guage to bring it under control.

I would only move to the fully locked position if you are looking for a quick getaway or on snow etc.

There is no problem changing the setting whilst on the move it is some form of electro magnet that does the changing.

Not quite sure by what you mean when you say the car jolts when in the orange but you will have great dificulty parking when in this position.

Darren

When trying to drive with the centre diff set to one of the orange positions, it feels like something is not engaging properly, or the diff is slipping.

Also, you say you move to the second green position when it's wet - I use that as standard at the moment but the back end lets go without much provocation at all even in the dry. The tyres are quite worn, but this shouldn't make too much difference in the dry.

Thanks for your help

Mike Hall

I went to Santa Pod on Sunday - with the diff lock forward i got a much better launch (no wheelspin) but it didn't feel as quick as it should have been (psychological maybe?).

Is it particularly bad for the car to move the diff lock back to open whilst going flat out through the gears???

Dave (STI-V TypeR)

Mike/Darren/Dave,

I have the same doubt with the proper use of the center-diff-lock. Well, what I have found in practice, for what it's worth, is the following :

Dialled in all the way to the back (ie. bottom green) this is useful only for the driest of dry roads. The bias of power seems to be significantly towards the rear on this setting (and mainly the reason why I recently changed from an EVO6 to the Type R STi5). So there's your fun rear-wheel-drive car.

Then the only other setting which I find useful is nearly all the way to the front (ie. last orange setting before the 'LOCK' position / just before the forward-most 'click' on the potentiometer). This I use when the roads are wet or slippery and keeps the back-end in check (ie. it doesn't swing round quicker than you can say "rear-end!" when you don't want it to!).

That 'knocking' noise you're talking about - that should only be happening if you're doing slow, nearly full-lock manoeuvers - definitely not if you're travelling in a straight line, at any speed.

There are two main things which I think are true:

1. I don't think it's safe to use the 'rear-most' setting in wet/slippery conditions (it's plain dangerous!).

2. You should never use the fully "LOCK"ed position unless you're on gravel or other such loose surface (like snow - but then 300bhp on snow frankly is asking for it!) otherwise you'll wear out your drivetrain.

Does anyone maybe have a Japanese translation of the section in the manual that tells our japanese counterparts how to use this facility???

Then we can all sleep at night. Well, sort of anyway...

Richard.
(An EVO6 -> Impreza convert)

My brother was talking to a Subaru garage the other day and happened to mention this query. Apparently, the advice from them was that the 'yellow light' positions should not be used at all on the road as they lock the diff in varying amounts.

I really don't know where I stand now!!

Mike

This is not helpful for Mike, but I was chatting to my mate at Ralliart at the service in Neath, and the talk got onto this topic, his question is has anybody tried runiing their diff actively?
This is what the rally cars do, mind you they run all 3 actively. Apparantly braking performance is much improved if the diff is locked under braking, the rear wheel brakes are effectively also braking the fronts (hence huge rear brakes on rally cars).

As the diff is alreadt electrically controlled hardware costs should be low.
Don.t know how turning under braking would be affected but with only 1 diff the map should be fairly simple.

Any comments on turning agility with the diff locked? Or indeed is anyone feeling adventurous?

I can only add to the discussion by inviting you all on a MIRA wet handling day. The fun you can have learning which setting to use for which extreme manourver is endless.
The oversteer junkies like to have the control set to the rear. The quick guys move it forward in tight corners. If you go too far forward the problem of tyre wear may well rear it's ugly. (if the centre diff locks that is.)It's all a bit academic on the road.
Call me 01628 784911 or see

MMM so turning is fine with the diff locked locked, who is going to the first with an active centre diff? Can't be me as I've got a 4 door;(, or can anyone see Stef fitting one to his UK car for even better braking?