R56 how can you tell
#1
how can you tell
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
#4
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.
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.
#5
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.
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.
#6
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.
#7
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.
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.
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#12
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
#13
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
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
#14
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
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
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”.
#15
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.
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”.
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”.
#16
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..
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..
I think it tells me I don't have an open diff, so it must be LSD.
#17
#18
Without LSD and ASC turned off, I think an MCS would easily squeak a tire when making a sharp turn from stopped.
#19
#20
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
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
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.
#21
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.
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.
#22
It was always purely mechanical from what I've read. Unless you're confusing it with the new EDLC, not the old mechanical LSD.
#23
#24
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.
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.
#25
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.
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.