i just leased a new 09' MCS last week and one of the options listed on the window sticker is the $500 factory limited-slip differential. is there a way to tell if its really installed on the car by the vin or something? i personally cant tell by my seat of the pants driving impression. any thoughts? thanks

 

Test drive one without it, and you will know the difference. Without LSD the steering really pulls to one side or the other when you get heavy on the throttle.

Mark

 

Call MINI USA (866-ASK-MINI) and give them your VIN. They will be able to give you all factory build information.

 

I'd say if it was listed on the sticker, it's in the car. Is there a reason not to trust the window sticker?

Also, if all the tires are filled correctly and worn equally, cars without the limited slip diff don't pull to one side or the other (torque steer). My 08 MCS tells me that the tires are low by torque steering under acceleration, but if I keep up with the tire pressures my car accelerates straight. Limited slip diffs are for when there's a drastic difference in traction between the two powered wheels, not for managing acceleration.

 

My LSD equipped MCS pulls one way then pulls the other way under hard acceleration. This characteristic was mentioned in a MotoringFile article on LSD being discontinued.

So, if your MCS weaves like a drunken sailor under hard acceleration, you have LSD. If it just pulls one way, it doesn't. That's my theory.

 

An indirect way to confirm you have LSD is to look underneath the car and see if you can locate a sticker on the transmission. The sticker shows the transmission oil type. If it says MTF-94 on the sticker, then that's the oil for the LSD transmission. If it says MTF-LT-4, that's the oil for the non-LSD transmission. Of course, this is assuming they put the correct sticker on.

 

A limited slip diff won't effect torque steer, that's a function of how equally power gets distributed to the driven wheels through the tranny. A limited slip diff works when there is a difference in traction availible between the two driven wheels and prevents the wheel with the less traction from spinning too while the wheel with more traction just sits there. Traditionally, the limited slip diff is used on racing cars to prevent loss of acceleration during turns, when the driven wheel on the inside of the turn has little or no load on it.

Here's a brain wave about to test if you have a limited slip diff during winter: stop the car with one front wheel on a piece of ice and the other on pavement, then try to accelerate. If the wheel on the ice starts spinning and the car doesn't accelerate, then you have the stock open diff. If both wheels start to turn and the car accelerates, then you have a limited slip diff.

 

If it is on the sticker, then you have it. This isnt something that someone would remove from the car.

 

I agree, if it's on the sticker you have the option.

 

take a corner fast while accelerating. everytime I do i'm glad I have LSD

 

Merry Christmas, all.

 

Launch with the wheel turned and see if it goes straight off the road Actually, if you drove one without you would know. Go real hard around a corner in one gear lower then normal and hit it hard. The LSD corrects the understeer a bit and gives you a lot more traction around corners. I made it a pre-requisite of any used MINI I bought and bought a color I normally would not have just because of the LSD.

 

Wow... all of these replies, and all of them are "put your tire on ice" and " if t torque steers, then this...."

first point, Torque steer is almost 100% dues to the fact that you have different suspension, and driveshaft geometry from side to side. i.e. one side has a shorter driveshaft. But that's not what we're talking about.

The EASIEST and most effective way would be to
1) jack up the front end
2) put the car in neutral
3) spin one wheel by hand

What does the other wheel do when you spin it?

If it turns the same direction as the wheel you're spinning, then you have an LSD

If it turns the opposite way? well... you got hosed and you have an open diff..


Now was that so hard? no need for slippery corners or ice patches, or measuring the deflection angle caused from torque steer. lol

 

Have you done this on an R56 MCS with LSD? Or, is this from theory?

Regarding torque steer and LSD, here is something from MotoringFile:

MINI engineers found issues with LSD on the high torque engines of the JCW and JCW engine kit. Specifically due to the high amount of torque, LSD causes the car to engage too quickly causing what’s been referred to as “anti-torque steer”.

 

It works on any car with a limited slip differential. Unless you are he-man with the strength of Thor, you won't be able to overpower it.

But... it is all in theory. However, I'd rather have a theory that works on 90% of limited slip differentials over "Put one tire on ice and watch what it does".. not all that scientific to me.

I don't understand why you posted this.. I never refuted this. All I was saying is that Torque steer MAY be from your diff, but it is almost always due to driveline geometry. Cool to know, though.

 

I tried that once, with Shawn who's supposed to have LSD. The other wheel did not turn, so what does that tell me?

I think it tells me I don't have an open diff, so it must be LSD.

 

well the window sticker said it had LSD and the sticker on the tranny says MTF-94 so she must be equiped with it. I just cant tell by driving it because we dont have any snow or ice here.

 

Without LSD and ASC turned off, I think an MCS would easily squeak a tire when making a sharp turn from stopped.

 

i still like the snow ice method...

with mine on.. you could floor it and it wont go past 3k rpm engaged... without, it could spin all day without getting anywhere

 

I love these MINI experts. Jacking up the car isn't going to do anything. This isn't a 1978 Ford Bronco with a locked differential. It's part time - spinning the wheel by hand isn't going to cause the other wheel to do anything! The LSD is computer controlled and engages with the tranny IN GEAR and the computer sees the one wheel is spinning (faster than you can make it by hand)!

By far the easiest way to tell is to put one wheel in gravel or on ice or some other slippery substance and gun it.

 

I never claimed to be a MINI expert. But physically putting the car on stands and trying to do something to it is better than "go drive it on ice" lol. I mean.. how can you even see both wheels? You'd have to have 3 people just to pull it off.


But you MINI guys do what you want. It was just as valid of a suggestion as any other. But by all means, feel free to make an example of me.

 

It is?

It was always purely mechanical from what I've read. Unless you're confusing it with the new EDLC, not the old mechanical LSD.

 

Someone is confused LSD can cause that, along with delusions of grandeur

Maybe a 2nd gen, 2nd edition forum is in order

Mark

 

I think we're getting confused about what a mechanical Limited Slip Diff is vs. computer traction control. The most common way for a computer to control slip is to apply the brakes on the tire that's turning too quickly. DSC works the same way, which is why computer slip control is usually paired with stability control, they're both the same system; they apply the brake on whatever wheel is spinning more quickly than the others. DSC does this to correct yaw, traction control does it to correct for excessive power.

Mechanical LSD's control wheelspin without resorting to the brakes, by controlling to which axle the engine power is going to within the diff, rather than at the brakes. There are computer controlled LSD's out there, but they're very expensive and I don't think MINI uses them.

What's so "unscientific" about placing each driven wheel on drastically different traction surfaces to test if the car has an LSD? The test plays directly into how an open diff works: as soon as one wheel starts spinning, the open diff puts all the availible torque into that wheel. The wheel on the ice should spin almost immediatly and will get all the engine power when it does so, making the presence of a open diff pretty obvious.

 

Most 2nd Gen MINIs have ASC (All Season Control). This is an electronic traction control system that simply cuts engine power when a wheel starts to spin. You stomp on the gas, and the engine bogs down. Having LSD delays the intervention of ASC.

ASC is not as efficient at getting power to the ground as the electronic systems that brake a spinning wheel. Braking the spinning wheel just enough to stop it spinning causes the differential to transfer the extra power to the other wheel. If the system is done right, it can be very effective. In the MINI it is called EDLC and is part of the DTC option. It first showed up in the factory JCW MINI.

My 2007 MCS with DSC does not have EDLC as it was not available until the DTC option became available. Mine has the horrible ASC. To turn it off, I must also turn off DSC.