22 replies to this topic

[Squatterjay]

I have recently bought a straight cut gear box and it came with a diff. My question is does anybody know the best way to set up one of these diffs, as it seems different to the tran-x types. I don't want to fit it in my car without knowing what it is set to (too loose to stiff). Any help or location of information would be greatly appreciated. It is going into a sprint/tarmac rally car. So if anyone knows the settings that would suit this application that would also be appreciated. Thank you.

[mini93]

Southam Mini and Metro centre have quite a knowladge of these. Not sure how useful they can be over the phone, without seeing it, but just incase its 01926 815681.

Located in Warwickshire, quite a way from you...

[Squatterjay]

Thanks very much, I'll give them a call!

[Ivor Badger]

For rallying = as loose as possible. if forests = don't fit, unless you wish to enjoy the scenery (personally).

[fastcarl]

Is this info based on  personnel experience?

 

 

For rallying = as loose as possible. if forests = don't fit, unless you wish to enjoy the scenery (personally).

Edited by Cooperman, 27 October 2013 - 02:58 PM.

[Cooperman]

For rallying an LSD is not really advisable. I do speak from experience. For gravel it is a big no-no.

It can be difficult to drive on narrow twisty tarmac with an LSD as the car grabs and pulls. If it then runs wide onto a grass verge the wheel with the grip, i.e. the one still on the tarmac, will grip and pull the car off the road. The other problem on a rally car is that if you enter a corner too fast and lift off the car will under-steer off. To have a chance of making an LSD work in rallying the driver must be able to left-foot-brake effectively.

It's different for a race car where the important thing is maximum drive from both front wheels and you can get back on the power early in a corner.

[Squatterjay]

I run service for many types of rally car vauxhall nova,Peugeot 205'mr2 escorts ect ect and they all run very tight diffs car is approx 120hp problem I have is putting power down out of the corner the inside wheel is always spinning , I can left foot brake effectively (or so I feel) problem is tho as the car settles again massive loss of traction was going to buy a tran x but when this g box came up for sale seemed a good option

[ybrig1]

I ran a Clubman Gt in the early 80's with 78bhp at the wheels with a 4.1 diff and sc box. It was fitted with a salisbury LSD. Traction was incredible, did forest and tarmac rallies. Fitted the big standard Clubman GT steering wheel to get the leverage and hold on to. Was a good package. Believe it was set to 35lbs or something like that. It stopped the nearside wheel spinning up in tight corners and for forest stuff was ideal. Just hang on and keep your foot in there!

 

Neil C now retired

[Cooperman]

My old friend Russell Brookes did the RAC in a Mini a few years ago and he reckoned the LSD with which it was fitted cost him around 15 minutes overall. He hated it in a Mini.

I've tested many rally Minis with LSD's and when tested back-to-back with mine, Peter Horsburgh found mine with just a X-pin was faster and much easier to drive on both twisty tarmac and loose. He immediately took his out and reverted to my spec - then beat me on the next rally we both did, him first and me second!

I think the Mini is a special case as the short wheelbase makes the car 'twitchy' at best and with an LSD it can be very difficult to drive to its best.

[mk1coopers]

Sell it and put the money towards a Quaife ATB if you are allowed to run one (or girls diff as some people call them  ), you can feel them working but they are much more predicable and shouldn't spit you off the road. I did drive a metro grass track car once with a welded diff, now that was hard on you arms!

[revolution12345]

if possible get a ATB diff. It isnt as aggressive as a plated diff, we use them for autotesting and we can still circle pylons no problem

[rally1380]

Interested in this subject and would like to know from people who have used such diffs first hand what makes a ATB diff so different to a more agressive LSD?  Does a ATB offer the traction of a LSD but without the spit you into the nearest tree snatch like tendancies?

 

Would like to hear more as a LSD is something I am considering (in the distant future) but don't like the idea of a twitchy car...probably best just saving my cash and sticking with the X pin I have until something goes pop.

[Spud_133]

With the ATB in my hot rod, which is running an English axle, you get both the advantages of a free diff when going into a corner, but they lock up so you get the affects of a locked diff when coming out of a corner, and you can get on the power earlier.

[Cooperman]

An LSD in a RWD car is excellent and all the Escorts and Datsun 240Z's I ever rallied in always had one.

However, in a Mini they are hard to drive on multi-surface rallies. With a Mini if a corner tightens and you are going a bit too quickly, you can lift off, the car will go into over-steer, and then you t back on the power when it's safe to do so. However, with an LSD in a Mini, when the corner tightens you must go hard onto the power to try to 'pull' the car around the corner. If, as is the natural reaction, you lift off then you will simply under-steer off. But, even if you hit the power the car may still slide a bit wide and if it hit's a surface on the outside of the corner which has less grip, even with the power on, it will be pulled by the wheel with the most grip straight off the road. And yes, I do speak from experience of this.

[revolution12345]

Quaife make the ATB. See their website, explains it. Its a geared differntial, never needs set or adjusted. With autotesting I get alot of fillings into gearoil and it has never affected the unit. Fit and forget. As explained above, on normal cornering it allows split wheel speed but if it does start to spin one out of control it limits the spin but doesnt lock up and pull aggressively across the road. See Ken Wharton 2013 videos on youtube, all them minis use ATB and the Novas
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