All I know is that the MCS has a mechanical LSD and the JCW factory car has an electronic Differential. Could someone explain to me how they work and is the electronic one better than the mechanical one?

Thanks

 

I've yet to hear someone stand up and give a good reason why you'd want the eLSD over the LSD.

Time to sit back and watch the shower of pro-LSD comments.

 

So are you saying the mechanical LSD is better? Why?

Thanks

 

Do you prefer real sex or cyber sex...there's your answer

 

Why would they put an inferior LSD on a more powerful car? It doesn't make sense?

 

that is the best analogy I have seen to describe this new lsd haha

 

I'm curious about the eLSD, too. I honestly don't know anything about it/them, but my initial thought is that it would be like a glorified electronic traction control. Maybe they've got a system that works well. I would think it would be easy to intigrate with the traction control and DSC.

 

Ha. Thumbs up for that one.

 

!!! Thats a perfect way to explain the difference!

You're basically right, it's a glorified electronic traction control. It will brake the wheel that is spinning...to help "give it more traction". A real LSD will transfer power from the slipping wheel to the wheel that has traction...it keeps both wheels moving and spinning, whereas a eLSD stops 1. It's really stupid...and I can't believe the JCW car will have that, where does it say that's what it will have? Makes no sense to me.

The new 135i has an Electronic LSD as well...apparently it works pretty well, but its no match for a true LSD.

 

seriously... it will work, but it will not out-perform a true lsd...

why rob power in order to get traction when you can mechanically move the power to a non-slipping wheel... i'm seriously betting that a real lsd car will have a bunch more speed coming out of a turn then an elsd car..

 

So what you are saying is that a MCS with a true LSD that has been moded to about the same power as a factory JCW car will outperform it on the track? given they have about the same stopping power and suspension set up.

 

On an eLSD setup, when you brake the spinning wheel, you are not only stopping it from slipping, you're using the open-diff to transfer torque to the wheel that's not spinning. It's essentially an electronic torque biasing system, however its functionality is in direct proportion to the systems ability to be quick and precise. If it's lazy and laid-back like Chrysler traction control system it'll be worthless, and conversely if it's dramatically overactive like BMW traction control it may just ultimately slow the pace of the car. The open-diff planet gears will get much more abuse from this practice, and the front brakes will be worked even harder than they already are in spirited/track driving. MINI is claiming an effective 50% lock, which is an absurd statement based on how the system works with an open-diff; it can't lock, just transfer torque....unless the brake BOTH front wheels simultaneously?!

Short story shorter; I find the system easy to implement from a hardware perspective [it's just more software], however in terms of ultimate pace, it won't beat an instantly reactive mechanical ATB like a Quaife.

 

So, essentially, it's the ACS traction control made to monitor/affect one wheel at a time rather than monitoring each but affecting both if one slips. Yeah, if it works as intended, it would theoretically be fine, albeit with a bit more wear on the front brakes.

It seems then, that you could still install a Quaife (or swap in a MINI mechanical LSD unit), get the benefit of the true LSD and pre-empt the eLSD from having to kick in. It's too bad in MINI ends up dropping the mechanical LSD altogether, but I can see where it would make sense from their standpoint since all of the cars are DSC equipped now anyway.

 

mmm, interesting.

On the higher performance car, I assumed that the eLSD was a computer-controlled diff like in a Rally or F1 car. If it's really software only, that's lame IMO.

 

BMW/MINI eLSD is basically NOT an LSD at all. eLSD is just a marketing term like "soy milk" is fake milk. It's electronic traction control coupled to an open differential which applies brakes to the inside unweighted tire when it spins under traction loss, thereby transferring torque to outside weighted tire. BTW this is not to be confused with electronic LSDs some manufacturers use which describe a mechanical LSD where the clutch plates are under electronic instead of mechanical control.

A true LSD consists of a mechanical device which physically connects the left and right axles using mechanical force to compress clutch plate(s) together. Both tires are forced to turn at the same rate until the difference in tire rotation speed overcomes the mechanical force and causes the clutch plates to slip so the tires can turn at different rates, like when going around a turn.

eLSD is weightless and cheap. It's just software which uses the existing hardware for ABS/DSC. It can be programmed to whatever % slip is desired by MINI. Because it uses the brakes it works by slowing the car down. Also because it uses the primary brakes used for slowing the car, the fronts, it can cook the brakes. It's not really good for racing.

Mechanical LSD a mechanical device so it adds weight and the way it works generates friction hence heat in the transmission. A tranny cooler maybe needed for heavy use. It can also eventually wear out and need servicing. It's a performance enhancing device which increases traction accelerating out of corners, which is why all race cars use LSDs.

On the street or in the snow, it's probably not much difference. On the track or autoX is hard to say without driving both.

Why would MINI would put an an LSD in the MCS but eLSD in the performance oriented JCW? The BMW M3 gets an LSD, the Porsche GT3 gets an LSD. At this point I'm just guessing, but the MCS GKN LSD has between 20-35% slip, which is fine for snow, but kind of low for the track. By going with an electronic solution, MINI was able to increase the slip to 50% without sourcing another vendor for parts and at virtually zero cost.

 

a mechanical LSD = faster cornering through transfered power
the eLSD = less spinning tires while cornering through braking

as everyone's pointed out, it's basically a software tweak to the AST+DSC and costs Mini nothing to include in the manufacturing . It sounds good and 90+% of the people buying the JCW package wouldn't know the difference.
Anyone really serious about performance would go the aftermarket route, rather then pay ridiculous prices for the mellow JCW gear. Even the mechanical "Super LSD" is pretty whimpy & would be better replaced with a Torsen or Quaife depending on your driving style.

 

I would guess that MINI didn't think MCS LSD would handle the power of the factory JCW, and due to the limited production of the JCW, didn't want to spend the $$ on designing one for it.

 

Quaife vs. eLSD? That's an interesting choice.

Quaife is a torque biasing differential (TBD) so it is not a true LSD either. But it is mechanical and doesn't use braking to limit tire spin, which is good for performance. Also because it uses helical gears and not friction clutches there is less wear and tear and less heat generated. The downside is that if the inside tire is completely unloaded i.e. up in the air or on wet ice, then, unlike an LSD, a TBD behaves like an open diff and there is zero torque transfer to the outside tire. In the same situation with an eLSD, presumably it would brake the spinning tire and transfer torque to the grounded tire. Both would have zero lock up on braking which would be good for trailing brake oversteer for those tight autoX corners.

 

Great answer!

It seems to me that if you really want to race your MINI, then get a 'regular' MCS, and then make all the aftermarket mods to it you want, including a mechanical LSD that's better than the MINI factory one. And that means that if track performance is your goal, then it's competely reasonable to criticise the eLSD that's part of the new DTC on the factory JCW car.

On the other hand, if you aren't taking your car to the track, then those folks saying that the JCW car is 'ruined' because it comes with an eLSD rather than the mechanical LSD option - well, they are dramatically overstating if not distorting matters. My guess (I've not driven an eLSD car) is that for even the most spirited of street driving, the eLSD will perform extremely well - and will match if not improve upon the street driving characteristics of the mechanical LSD that MINI offers.

 

A diverse set of replies; and all informed and level headed even if not in agreement. northamericanmotoring.com has a great bunch of members.

I'm in the market for a R56 MCS, and now contemplating the JCW having delayed so long. Having a C43 that uses as very 'early' version of 'eLSD-like' functionality from a decade before, I can attest to the fact it does less than zero off turns but is 'slightly' helpful off the line... (less so now w/my 5.4L installed) I was very worried about its use [reliance] in the JCW. From readings here discussing 'theory', + comparative pros & cons of all options, to readings in other places where it was based on a test drive, and having a decade of technological evolution behind it from what I have experience with, I do feel at least slightly better about its use in the R56S JCW vs. using a 'real' LSD.

If you add up all you get for the JCW...Still bugs me Mini/BMW seems to price its addition into the overall package as if a mechanical unit were added. A $6500 premium for a JCW equipped as I want (near loaded) vs. a regular MCS. No suspension upgrade. Brakes upgraded. The rest of that cost can't all be all engine + intake + exhaust + a bit of minor things.... just isn't warranted. So what, they threw on an extra grand into the cost for this eLSD-like functionality?