54 replies to this topic

[GraemeC]

You could get pot joint outputs and use the adaptors from Swiftune or MED to go to Hardy Spicers.

(or if you're really lucky find some original Mini Automatic ones which are the same thing essentially)

http://www.swiftune....diffs-pair.aspx

http://www.med-engin...spicer-adaptors

[Northernpower]

May be the atb would have been an alternative. I bought the Tran-x and it is a much better drive compared to the old style plated salisbury.
But my next step would definetely be an open diff. Question is, where can I get the parts? I would need new output shafts for the hardy spicer coupling these seem to be no longer available.
What else do I need?

I think you'll find these output shafts http://www.swiftune....diffs-pair.aspx  will fit the cross pin diff.

Edited by Northernpower, 31 March 2017 - 12:13 PM.

[Lenhamracer]

Very good advice, I didn't know that they are doing adapters

[Mervyn]

Atb if a plate diff doesn't suit your style.

With atb you will lose drive if a wheel hops though so good suspension setup a must

Atb all the way for me except if on gravel

Merv

[Lenhamracer]

Sounds interesting. Anyone else with experience with the ATB diff? As far as I undeerstood it won´t snap in suddenly if a wheel is on loose surface, do you also need three arms to hold the steering wheel in tight bends when accelerating out of them like on a plate type LSD?

I have found two open diffs in my garage, one for pot joints and the other one is the old type for the rubber coupling. Also I have various crown wheels and lots of pinion wheels and the covers of the diff case for pot joints. Only thing needed would be the adapter to hardy spicers or I could go back to pot joints?

[MIGLIACARS]

I use to snap hardy spices all the time when using my 1380 mini 

 

the metro came with pot joints and has had the same ones now since 2003 it no problems. with nearly twice the power

[The Principal]

I have run an ATB diff on a road car for the last 5ish years its progressive and doesn't snap, on a spirited exit of a roundabout you can feel it but it doesnt overly drag on the steering. ATB's come with standard output shafts meaning you can use pot joints. The main difference is the ATB is a geared LSD unlike the clutch type hence it wont lock or grab.

 

Quaife sales pitch - Silent in operation (even during low-speed parking manoeuvres) the Quaife ATB limited slip unit never ‘locks,’ making it progressive, safe and user friendly. Unlike plate-style LSD designs there are no clutches, ramps, springs or other wear prone components to replace at regular intervals, because the Quaife ATB’s well-proven system of helical gears is extremely durable, plus it’s designed to use standard transmission oils

 

only downside Quaife wont sell it direct and the price keeps going up but it does have a lifetime guarantee 

Edited by The Principal, 01 April 2017 - 10:16 AM.

[Spider]

I run an ATB in many of our cars.

 

I have tried Plated LSD years ago. On sealed surfaces, it could almost be liveable, but did need a careful set up to each and every corner with loads of power all the way through. Fine but if you needed to deviate from that line or lifted the slightest, the car would want to run wide every time.

 

On loose surfaces, it was worse.

 

Gawd awful things in FDW Cars IMO.

 

The ATB (Quaife) on the other hand I find is that happy medium. I've kept an open mind about them and the more I've driven with them, especially in the loose, the more I am sold on them. They really are just brilliant. You will still get wheel spin on the wheel with less traction, but unlike an Open Diff (bloody useless) you'll still have considerable drive through the wheel with traction. If you do loose 100% of traction on one wheel it won't drive through the other wheel. This is the trade off they have for having a Diff that's not going to try to rip the steering wheel from your hands. 

 

<EDIT: Although I've said that you will still get wheel spin on the wheel with less traction, that wheel I've found is considerably less so inclined to spin in the first place and wheen iit does, it's nothing remotely like an Open Diff.

Also, the ATB, unlike any Open Diff (X-Pin included) won't break,>

Edited by Moke Spider, 01 April 2017 - 09:28 AM.

[CobraV8]

I have a quaife ATB in my car. When I first put it in, it was a handful, and I thought was a mistake. I then replaced the sloppy steering rack, and it is a great car to drive.

I was told you should get rid of rubber slop in the suspension, so have all rose joints, solid subframe mounts, additional engine steadies top and bottom, hard poly mounts in standard engine steady.

You can run smaller camber and caster, and seems to make it easier too.

With all the above done 13x7 and 10x6 are both good.

[Cooperman]

If you are pushing hard through a forest on gravel and you find a corner, to which you have already committed yourself, suddenly tightens, the impulse is to lift off. Now what you then want is for the front to turn in more and then, when that happens the car will start to spin and you give it full power to keep the front in front. In the worst cast you simply spin around the corner. However, if you are a real left-foot-braking (LFB) expert you don't lift off, you just feed in some left foot braking, the rears tend to lock and the car turns in. This takes a lot of practice and it must come completely naturally. Paddy H. said he has never mastered this technique and relies on the 'lift-off' method of dealing with a corner which tightens.

With any sort of LSD you need to completely master the LFB technique until it is second nature, otherwise on a rally, you will eventually run wide at speed when a corner tightens and you are going a bit too fast.

It could be different on tarmac rallies with full pace notes as you have advance notice of corners which tighten and can enter a bit less quickly, then get back on the power sooner and exit at a higher speed. An LSD will help with this, but at the expense of being able to drive really smoothly.

The big question is how many seconds per mile will you gain with an LSD and only a test of this on different surfaces will answer the question.

We can al talk about it, but a full test is needed on both known and unknown roads being driven as near to 10 tenths as possible by the same driver in the same car. Then you would know for sure.

[Spider]

I agree Cooperman that Left Foot baking can be used to great advantage once it's mastered and it takes a while to use it to effect and improve one's times, not that that should discourage one from learning it.

 

However, if the front end doesn't steer and effectively always wants to drive straight, then no amount of left foot braking will bring the back around, it will only retard forward movement.

[Cooperman]

Personally I would never use an LSD on a rally car because eventually I am going to enter a corner far too fast and with the natural reaction being to lift off I need to know the car will turn in and go into oversteer. Since lifting off in a corner when an LSD is fitted just promotes understeer I would, quite simply, crash unless I left-foot-braked. If I did go in too fast with an LSD I would need to press the throttle pedal to the floor and thump the brake pedal with the left foot. This would increase the oversteer and, hopefully, get the car pointing the way I wanted to go. Remember, with an LSD, power on in a corner will make the car turn in more, but if you are going too fast anyway it will simply mean you are going off anyway, but at a higher speed!

 

To be able to left-foot-brake consistently and without even thinking about it does require a lot of practice. I once had a SAAB 96V4 which I used to left foot brake and I became quite good at it, especially in the wet and on snow, but that is a longer wheelbase than a Mini and I have never really mastered it in a Mini. It is also necessary that the car is not fitted with a servo as when the vacuum runs out during a series of left-foot-braked corners things become very difficult if a servo is fitted. 

[Allrounder]

I've got the atb in mine. Using it for various disciplines. On a seal surface it drives no differently to a open diff but is about 2 may 3 seconds quicker per 1 minute test. Other competitor of mine has a plate diff in a micra and informs me at times it's hard to pick the best line as he's fighting the torque steer. Not really drove the atb on the loose yet so not sure how it behaves.

I do remember my first lesson with a plate diff on gravel though in a 180bhp nova. After nearly going off on the first corner I was told to steer it with the rear end and soon got into the swing of left foot braking and setting the car up much like a Rwd.

[rally1380]

Can I ask what spec the LSD's folks are talking about which make mini's so undriveable?  I have heard stories of older diffs making cars behave terribly, but would like to know what's going on inside the guts of these diffs as modern diffs offer a whole myriad of ramp angles and pre loads.

 

I know LSD's of old were pants......but why?

 

And using this info, surely the very different ramp angles on off from MED's NXG diffs, will give each setup very different characteristics?

 

I'm not saying anyone is wrong (or even right), i'm just suggesting that maybe it isn't black and white anymore and there is very much a grey area to explore.

 

And ATB's are definitely a good alternative......we'll come to Torsen diffs later. 

[Will16]

This thread isnt giving me much hope for the torsen lsd I've put in for my k series swap