My sister bought her BRG 2010 MCS around 2 months ago. We decided a thousand-ish miles was good enough for break-in, so we took it to a cute little autocross out by Madison, WI. We were both absolutely amped because it's such a fantastic street car and I've seen 1st-hand how brilliant justas and MCSs can be on an autocross course.

It was awful. Absolutely terrible.

I certainly can't complain about the total lack of throttle response when sport mode wasn't on, because that was just my fault for being to stupid to turn it on. Personally I think the default when you turn the car on should be sport mode, and if you want to castrate the car then push the button for weiner mode. IMHO.

The real core of the issue, and the reason the cobalt beat us by a full 3 embarassing seconds, is the LSD. It just plain didn't work. I do understand that the '10 wasn't offered with a real, mechanical LSD. We looked for a month for a car that did. I was promised and guaranteed and assured that the electronic LSD worked just as well, better in most cases. While I certainly didn't believe that nonsense, I never expected the situation to be this bad. With traction control on the car was a dog pretty much everywhere. With traction control off it was absolutely impossible to put any power down on corner entry, steady-state, or exit. The inside wheel would just spin maniacally. It's not possible that the e-LSD turns off with traction/stability control, is it?

Is anyone else out there running a car with this computer-driven LSD thing? How the heck do you make it work? Is our car defective? What were we doing wrong?

Many thanks to anyone who can offer any advice at all. One of the reasons we got the car was to get her into autocross, but that really just wasn't any fun to drive at all.

Cheers~
--e

Cliffs Notes: How the hell do I get the e-LSD to work in these things?

 

I hate to say it, and I know you've thunk it, but this rings a bell..

Oh yes! My first season with the Works kit on before I had the Quaife -- that's it! I was the king of the smoking corner exit.

But the thing is that a JustaCooper with an open diff in the right hands can go unbelievably quickly.

So there has to be a way to drive them that works, right?

My approach was to OVERDRIVE! Early on the throttle and sliding into and out of the corners. That does not work - I have explored it thoroughly.

So how about seperating the braking, cornering and acceleration just a little more? Once the car has started to straighten up from the apex, the weight is rapidly shifting to the inside front wheel and the amount of throttle possible increases rapidly.

Rolling back into the power a touch later will avoid that initial wheelspin, and if it can be avoided then full throttle will actually move the car somewhere!

So I hate to day it, but there might be driver learning curve possible that would make a more dramatic and immediate difference than the usual remedies like OS Giken, rear sway bars, more tire, etc etc.

Just a humble thought from a sinner behind the wheel, who is still learning to be smooth after six years.

Cheers,

Charlie

 

The car comes standard with DSC. DTC is an option. If you have DTC you have e-lsd as you call it. If you have it, it cannot be turned off, and it should be applying the brake on the wheel that is trying to spin.

 

Awesome posts, thanks guys.

Charlie, I'm definitely no stranger to overdriving. Actually, it's kind of what I'm known for. That's part of why I'm so familiar with the feeling of a car beyond it's limits. Under conditions my 06 WRX wagon would have loved, the mini was a disaster. There's no way a 3300lb, noseheavy, FWD (for the sake of autox) pig like my WRX should handle better than a MCS. I'm sure we'll take it out again, I'll try driving at 85% next time and see what happens.

hsautocrosser, that's exactly the info I was looking for, thanks. I'll check the options package.

--e

 

The MC owner's manual suggests the button opposite the sport button will read either "DSC OFF" or "DTC."

 

one thing more (and again you bl**dy well know this) - the runflats are rim protectors suitable as a coffee table when properly stacked...

Bridgestone RE11, Toyo R1R, Dunlop Direzza Star Spec...

I always wanted to try a WRX - they do look fun, and Lord knows I've been beaten by more than a few over the years. I notice the owners tend to do "rain dances" under the right conditions to let their AWD advantage shine...

 

I helped buy the car and I'm pretty sure it doesn't have any optional traction goodies. It's pretty much a base Cooper S. The course last Sunday was 2 1/2 laps around a short oval track and there were 5 long sweepers where the car just sat with one paw in the air clawing at nothing for a lot of the course. Working the course and watching - it was pretty ugly. Without any LSD, the car is pretty well doomed to finish 2nd to any competent car and driver that has it. Mini's decision to kill the LSD just mystifies me, it's hard to accept the car as a serious driver's car without it. Brilliant everyday street car though...

The car does have black racing stripes hood to hatch and that should help counteract the lack of the LSD - That's worth at least two seconds, isn't it?

Jim

 

If it is true that "I was promised and guaranteed and assured that the electronic LSD worked just as well, better in most cases," then a follow up conversation is in order to explore remedies.

 

Too bad about the eDiff. VW has been using "EDL" since 95. They just release an new one in the 2010mk6 GTI. Its supposed to work better than the old EDL . As i recall it is a bosch system as most german ABS control is. You may check on info on it in other euro cars to get an idea about what could make it drivable.

The reason a manufacturer uses eDiff is cost. Mech LSD cost a bit more than an open diff. eDiff uses the brake pads to absorb energy (wheel slip). Brake pads are not a warranty item so there is no powertrain repair cost risk as there would be wih a LSD.

An open diff sends all power to the slipping wheel or wheel with least grip, or more correctly to the wheel with least resistance. TO make the open diff send power to the outside wheel the EDiff has to put more resistance on the slipping wheel with the brakes than the resistance of the grip and moment of inertia of the outside wheel.

Up to the point that the Open Diff is fooled The EDiff just absorbs power with the brakes.

stuff to try to make the eDiff work better (Transient action, and Exit Grip):
Transient action : DOT 4 brake fluid, Aggressive Pads, Lighter Wheels/tires. With less moment of inertia (spinning mass) and more power absorbed per brake pulse the eDiff will get a faster reaction from the slipping wheel. So hopefully is can do less with more.

Corner Exit Grip. Changing Grip on the outside tire...
The outside tire is loaded with weight on apex and exit.
1.Try to observe if the outside tire is squeeling too.
if it is then it is overloaded with weight and sliding, the grip is no good on either wheel and the EDL will not be able to send power to the outside effectively. To get more grip try increasing pressure (eventually you start loosing grip if you go to high). either drive easier or get grippier tires to BEAT UP.

Most tires have a max load. your MCS prob has about 800 lbs static load on each front tire. if stock springs are ~200lb/in and you have 3" of compression that would be 600lbs. So say 1400lbs on the tire. (These #'s are estimates I drive a Prepared class car and have no idea about stock mini suspension rates or movements). To check your max strut compression put a zip tie around the strut shaft and push it down to the strut body. Go through a hard sweeper, or tight apex. See how high it gets pushed up from the top of the strut body. that's how much your spring compressed. multiply by spring rate. estimate loading compare with max load.

If the outside tire is squeeling DO NOT Get Om The Throttle. The eDiff will just make everything a bad game of brake pong.

2. More grip on the outside tire seems like a good thing (with a mech LSD it is). BUT the ediff is making the Open Diff sense the outside tire has less grip than the inside slipping wheel. So the more grip the outside tire has, the more the breaking force the inside wheel gets i.e. more eDiff usage and power sucking. You'll have to balance GRIP with Driving Discipline.

In addition to pulsatting Brake resistance to Flop the Open Diff the EDiff is also slowing the inside wheel.
Ideally the the inside wheel is slowed just as the resitance force becomes greater And the torque is transfered to the outside loaded wheel.
Remember, the inside wheel isn't loaded with weight so any power applied to it will make it spin.

with DSC on the steering position sensor and load sensors could let the eDiff know how much your trying to turn and correct the inside slip to a good degree. (But it cuts throttle too So don't do that)

with DSC off I'd assume.. that the eDiff slows the inside wheel until it doesn't slip. meaning the power has transfered to the outside wheel. then the eDiff pulses less power until slip is detected again. Sort of like Early 90's Lambda Motronic ignition mapping that would just advance step by step until a knock was starting.

With a given tire setup the eDiff will likely work best at a certain cornering force. So Set up a skid pad circle and try different radius at various speeds.
try a 40' circle and see what the fastest speed that feels smooth is. then 50'

make a graph of what feels good. and mark when it goes ape.
try this with your stock wheels. See if you can borrow or buy some used (even dead) rComps and lightweight wheels to see the difference.

additionally a stiffer strut will make the eDiff react differently. too Stiff will likely make slip happen more often.

the anti-roll bar will affect weight transfer and therefor loading so resistance on the diff.

THE BAD NEWS... if you install a mech LSD. the eDiff will still be active. This will introduce a quirkyness to the handling. It will probably be mild but suspension's handling will seem to change ratios. You can learn to drive it but quirky is annoying if you drive differnt cars.

on corner entry the outside wheel loads up and the quaife sends proportionant power to the outside. ideally Power after the Apex should be applied proportionantly to the loading and grip. Most of the time it should work. and there is no eDiff.

too much power too early and the inside wheel will still slip. if the eDiff senses slip it will begin putting resitance on that wheel with the breaks. The quaife will then see more resistence on the inside and send more power there. creating a loop that will dump power to the inside and cause weird handling. --hey maybe you could be a FWD drifter.

anyway. try loosing wheel tire weight, Pads, and driving smoother. Good luck Stock is a better place to be if you can make it work.

 

To Discipline your throttle input better imagine there is a string from your right toe to the steering wheel. when the wheel is turned your toe doesn't go down. As you unwind the wheel you can press down the throttle.

 

Pretending for a moment that the car didn't come with the DTC, 1)what does it take to add a real LSD to a car that didn't come with one 2) can DTC be added to a car that just has DSC?

You guys are a great help, thanks

--e

 

unbolt axels from flanges, disconnect clutch and shift linkage, drop the transmission, remove the open diff, replace with LSD, good time to change clutch and flywheel. Put everything back together.
Welcome to STX, or FSP.
Most people wait until the clutch needs replacing or something in the trans breaks to change diffs.