Hey everyone,

I ordered my MCS with a limited slip differential and it was included on the build list, but after experiencing much more understeer than expected at a track day yesterday I'm having my doubts about whether or not it was actually put in the car. Even an instructor riding with me commented, without any prompting, that he felt like my car needs an LSD.

So today I jacked up the front and did the standard rotate your wheels test, but the results are a bit confusing to me. With the tranny in neutral, I spun the drivers side wheel and it spun but with a good amount of resistance while the passenger side wheel did not move at all. With the transmission in gear, I spun the drivers side wheel and the passenger side wheel spun the opposite direction, which doesn't seem to bode well for me.

Can anybody confirm from these results whether they think I might be missing this oh-so-crucial part?

 

My impression (and witnessed on my Subaru, which had an open front diff, and a viscous coupled rear diff) was that the opposite side wheel spinning the opposing direction = open, and spinning the same direction = mechanically coupled.

Not sure about the spinning directions of these "Super LSDs" though. Try doing a smoky burnout - a fun, and almost sure-fire way of knowing.

Also, you can crank the wheel in one direction, put it in first gear and stomp on the gas. If just the inside one lights up with no action from the outside wheel, you have an open diff.


Or go to a MINI dealership and have them look it up by your VIN... if they screwed up your order, then they can fix it.

 

You have the LSD. Still doesn't mean you won't get understeer. Tires willplay a huge part, as well as the type of track and corners you experianced this on and how approached the corners.

These cars are incredibally front heavy, a rear sway bar some time with and instructor and a different approach tot he corners are things that can be done to minimize comensate for and eliminate the understeer and help cut downthose lap times.

 

Yea, get the rear swaybar. 19mm or 22mm. LSD is for coming out of a turn. Going in, you need the swaybar.

 

Thanks for the input, I understand how swaybars work and such, it just threw me off that I was understeering so heavily on my exits and that my instructor, after driving the car himself, didn't believe that it had a Limited Slip. It also threw me off because I could swear that both front wheels should have turned the same way in gear when raised and one was pushed, not the result I had.

A swaybar has definitely been next on my list for sometime and I'm looking forward to seeing my improvement! Thanks again for the input and any further insight is definitely appreciated.

 

That is the easiest way to tell. Should have been easy to tell on the track. Without LSD you come out of the corner with smoke pouring out of the inside side of your car. With the LSD if you tromp it too early your going to understeer.

 

Well...on the track you don't slow down quite like in autoX. So if your tires are smoking you are probably slowing down too much.

 

LSD or no LSD... too much speed into a corner and your going to understeer. LSD will have zero effect on that. You can try to fight understeer with throddle, but it's really tough with a FWD car. Your just asking too much of the FWD system. It's even worse if your running runflats on a cool day, they're going to slip, slide & generally fight for traction everywhere. The MINI really likes the smooth (slow) in - fast out approach at the track.

Without the LSD you'll get one wheel spinning up on corner exits under hard throddle followed by a bit of torque stear in one direction (left or right, I don't remember). With the LSD you can actually feel it modulate power. Theres a subtle left-right-left-right-left sensation through the steering wheel as it struggles to maintain grip. You can feel it in a straight line, from a standing launch, too.

So if it turns out you've got it, I would say tires... rear bar... camber adjustments up front and/or lowering all around.

So was the track day a blast? Where was it at? Who hosted/instructed?

 

Wouldn't he have to turn off AST for such a test?

 

Well, then, yes, turn off AST, crank the wheel, and stomp on gas.