this confirms my worst fear that BMW is increasingly relying on electronic pulsating of the brakes to replace the mechanical limited slip differential unit. i did not see it listed anywhere on the order sheet and i'm pretty sure it is not standard equipment.

 

This weekend I did an HPDE at Road America. There was new 135i (Comes with edif rather than LSD now), and the driver who is a VERY good driver--one of the best out there at the HPDE, and well respected by all the members, was underwhelmed by the edif (actually underwhelmed is being too kind), and he's putting a true LSD on. Incidentally, he couldn't find track pads, and burned through two sets of fresh stock pads midway through the second day.

Even more off topic, he loved the car--he's just going to add the LSD and a few suspension tweaks...

 

Other thoughts on the ELDC are requested. Apparently, mechanical LSD will not be offered on the JCW. The ELDC will come standard.


The dealer sent me the option configurations today. Can anyone confirm what comes standard on the JCW. (JCW brakes, suspension, brace,etc.?)

 

i have two questions about the new BMW eDiff:

1. does it have a speed cutoff after which it no longer is operational? this used to be the case with the audi EDL (elec diff lock) and porsche's PSM-type EDL.

2. if the brakes are used to apply pressure to mimic a mechanical LSD --does this make the brakes fade FASTER because you're using them to bleed energy of spinning wheels as well as the kinetic energy of the car?

 

where did all of the CooperWorks sycophants go?

i thought they'd stick around to explain the rationale behind using your front brake pads as an eLSD to replace a mechanical unit. i mean, it makes to use the front brake pads that way --they're only responsible for 70% of the car's braking anyway.

 

Just doesn't make sense, does it? Heat up the pads during a high speed launch just in time for them to fade out on you when you're ready to haul it back down to a stop. If it were rear wheel drive like a Porsche or BMW it might make a little sense, but not on a FWD.

 

my thoughts exactly.

a FWDer has peculiar enough problems having the front wheels steer as well as send power. now you're asking them to do even more? it's just trouble and the brakes simply don't have the added capacity to carry all that added heat during hot lapping --which presumably the CooperWorks car is intended to do well, no?

 

I guess I'll have to do the same thing I did on the '02 R53: install a real LSD.

 

In theory it sounds good. Slow down the wheel that's loosing grip enough so it gains traction again. As with any "new" technology, it still has to be tweaked. Once they get it dialed in, I'm sure all the haters/doubters will come around. I believe Superbike racing uses this technology or something similar on their bikes.

 

actually, i've been in a BMW (xi awd system that relies upon brakes to control wheel slip) and the brake system basically went into shutdown mode and flashed brake warning lights. i had overheated the brakes driving in some deeper slush because the plows weren't out yet.

sure would be fun to see this in a JCW factory car (brake failure because of overheating).

 

How many years has this technology been around? Someone's gotta be the guinea pigs

 

Braking to try to simulate a limited slip differential has been around for a while. I had EDL in my '99.5 GTI GLX. It sucked big time. 4.5 years later I got an '04 R32 that had a much more mature version of the same thing. It was much improved (and most importantly had an OFF switch and AWD), but I still would have preferred a mechanical limited slip on the front axle.

Braking the wheel w/ less traction and diverting power from it to the wheel that has more are two completely different things in my opinion. I'll take the mechanical version personally. Not offering a real LSD on the JCW from the factory is a bad decision to me.

 

Well, this is not good. This is the first I've read about this technology on this forum. If it has been around for this long and it hasn't been perfected or widely adopted, something must be wrong with it. It only takes several years for a "new" good technology to be adopted by the masses. Maybe this is why they went with bigger brakes on the jcw In retrospect, they're probably trying to take what is a street application and market it as a performance feature.

 

i don't understand this thinking. the BMW paradigm usually has the non-M cars to suffer without a limited slip and the M cars have an LSD unit. this is the reverse and a cheap way out.

the dodge calibre SRT4 (gobs of power, FWD) tries to use an EDL and i believe all of the reviews on it are terrible.

the mazdaspeed 3 and honda si both have limited slip units. my sense is that perhaps MINI will roll out this option once it's properly sorted in the 2nd year?

 

Since when does one need LSD on a single wheel drive vehicle?

 

Yes, at least they are putting real Brembos on the car.

 

Not LSD per se but the technology meaning, that brakes are applied to limit or eliminate wheel spin. But maybe it may not be brakes for superbikes but rather throttle (or the reduction thereof) and wheel sensors that monitor wheelslipage. True, the dynamics of two vs four wheels are worlds different so my example is slightly off base.