FAQ: BMW eLSD - Not your dad's open diff!

[Zombie1]

Originally Posted by brakthru

Has anyone figured out how to shut off or code out elsd yet? From my experience, shutting dsc and dtc completely off does not stop elsd or electronics from using the brakes, throttle cuts, timing cuts and boost reduction to keep the car in line under heavy throttle especially with high boost applications. Going WOT from a stop leads to power reduction for me mostly in 1st gear with all nannies off verified through logs. I also have a mechancel LSD installed.

Mine literally never goes on when I go from a dig, I also have alot of suspension mods done to help with traction. My new coilovers have 392lbs springs up front and 672lbs springs out pack that really help put power down.

[brakthru]

Originally Posted by Zombie1

Mine literally never goes on when I go from a dig, I also have alot of suspension mods done to help with traction. My new coilovers have 392lbs springs up front and 672lbs springs out pack that really help put power down.

That awesome man. Your car must ride good with those coils. Just stay away from BMW software updates which may change your traction control system.

[paradoxical3]

The OP isn't accurate. It claims it does not cut engine power, but this stupid system absolutely cuts engine power, though most will never realize it and it only happens on the road course.

If a wheel threatens to slip, it is individually braked: blocking momentum is directed to the wheel opposite, which thereby guarantees optimum drive power. When DSC or Dynamic Traction Control (DTC) is active, the engine power output is also adjusted.
If the sporting driver chooses to deactivate DSC or DTC, he still has the benefit of ADB-X, which then focuses on maximum forward drive and applies braking force only. A temperature control sensor ensures that the brakes do not overheat.

It won't throw a SES or any codes, but if you actually scan the DSC module on track you will see a code thrown that says "brake disc temperature too high, reduced engine output."

It has been killing me on the track. I even installed a mechanical LSD and it helped, but it still appears. Whenever I am driving the car hard with slip angle, the stupid computer thinks that I am overheating my brakes due to the differential braking corner braking and cuts engine power.

It is driving me nuts, and until someone can figure out how to code this out these cars are junk for track work.

[imported_mega]

are you disabling dsc completely? I have no problems drifting my car but if I do not long press that button the nannies will stop my fun

[paradoxical3]

Originally Posted by imported_mega

are you disabling dsc completely? I have no problems drifting my car but if I do not long press that button the nannies will stop my fun

Yes, I never run with DSC or DTC on.

What I am talking about is subtle. IT is a function of the braking and only happens on the road course, not on the street.

It is not cutting power because of the e-lsd directly, it is cutting power because it thinks the brakes are overheating after track driving with e-lsd intervention over a prolonged period of time. I can get maybe two or three laps in with slip angle before it happens.

[dcaron9999]

Originally Posted by paradoxical3

Yes, I never run with DSC or DTC on.

What I am talking about is subtle. IT is a function of the braking and only happens on the road course, not on the street.

It is not cutting power because of the e-lsd directly, it is cutting power because it thinks the brakes are overheating after track driving with e-lsd intervention over a prolonged period of time. I can get maybe two or three laps in with slip angle before it happens.

I noticed I have this e-diff braking behavior during tight hair pins at the track, even with DSC off and my Quaife LSD. As I unwind the steering wheel, and apply steady light throttle input, towards the end of my turn, I feal an obvious surge of power, as if e-diff induced braking is released...

[brakthru]

Originally Posted by dcaron9999

I noticed I have this e-diff braking behavior during tight hair pins at the track, even with DSC off and my Quaife LSD. As I unwind the steering wheel, and apply steady light throttle input, towards the end of my turn, I feal an obvious surge of power, as if e-diff induced braking is released...

I had the same experience and it sucks badly when you have all this power just to have it curtailed against your will. I have the quaife lsd too. Thank God. I have to say before elsd was updated on my car via software update, my car could easily spin wildly out of control in a good way with all this power. Over 425 wheel horsepower and 450 torque. I hate not being able to put all the power down anymore but I will say the car feels alot more safe than before and confident inspiring knowing the system is constantly trying to keep the car in line. In many cases, I can floor it and the system will intervene if the car can't put the power down safely by cutting boost, braking, throttle closures etc all while keeping the car moving forward. I hope somebody figure out how get around this problem. Anyone out there using the Alpina B3 Trans flash. I heard it may help in some way.

[paradoxical3]

Originally Posted by brakthru

I had the same experience and it sucks badly when you have all this power just to have it curtailed against your will. I have the quaife lsd too. Thank God. I have to say before elsd was updated on my car via software update, my car could easily spin wildly out of control in a good way with all this power. Over 425 wheel horsepower and 450 torque. I hate not being able to put all the power down anymore but I will say the car feels alot more safe than before and confident inspiring knowing the system is constantly trying to keep the car in line.

I am getting really sick of it because it is hurting my ability to turn a fast lap. Every single session my fast lap is the 2nd lap and then I start to lose power. It's not because of tire or brake falloff either (Nt01 and Stoptech ST60 BBK). Every time I feel the car doing that, I read the codes and it shows "reduced engine output, brake disc temp too high." Really sucks because I have a Pure Turbo upgrade and can't even use it on the road course.

[brakthru]

Originally Posted by paradoxical3

I am getting really sick of it because it is hurting my ability to turn a fast lap. Every single session my fast lap is the 2nd lap and then I start to lose power. It's not because of tire or brake falloff either (Nt01 and Stoptech ST60 BBK). Every time I feel the car doing that, I read the codes and it shows "reduced engine output, brake disc temp too high." Really sucks because I have a Pure Turbo upgrade and can't even use it on the road course.

Do you have the Alpina B3 Trans flash by any chance. I'm thinking about trying it since I read somewhere the traction control intervenes less by allowing more wheel spin. I'm not sure how the flash would help but I do know several modules including dsc, dme and Trans have to be aligned during the software update since they rely on each other to communicate parameters to influence the behavior of the vehicle.

[iminhell1]

What happens when the rear wheel speed sensors are disconnected?

[paradoxical3]

I do have the Alpina flash, but it doesn't really have anything to do with DSC or traction. It flashes the TCU not the DSC module.

When the rear wheel speed sensors are disconnected I have no clue what happens.

[iminhell1]

Well being the wheel speed has to be the primary input for the ediff, removing the input should disable it.
Question is what else will be lost and will the pending codes affect power output in any way.

[paradoxical3]

Originally Posted by iminhell1

Well being the wheel speed has to be the primary input for the ediff, removing the input should disable it.
Question is what else will be lost and will the pending codes affect power output in any way.

I'm guessing you'd lose ABS, and I'd rather not do that since the car is a daily driver as well.

[brakthru]

Originally Posted by paradoxical3

I'm guessing you'd lose ABS, and I'd rather not do that since the car is a daily driver as well.

That's correct different modules but they do depend on each other for certain values and inputs especially when the dme request torque reduction or delayed shifting which I've experienced.
I haven't disconnected the rear brake sensors and don't wish too because you will lose ABS and your speedometer. I believe the ecu will default to a low power mode as well. I have experienced all of the above after completely removing ABS fuses. I've also removed the dsc fuse and even disconnected dsc module. This results in low power mode also. The only thing that will work is reprogramming more than likely.

[brakthru]

Originally Posted by paradoxical3

I do have the Alpina flash, but it doesn't really have anything to do with DSC or traction. It flashes the TCU not the DSC module.

When the rear wheel speed sensors are disconnected I have no clue what happens.

How much power and torque do you think you are pushing? The reason I ask is because I recently updated to an e60 tune with jb4 which causes wheel slip when I punch it even when I'm already going 65mph in a straight line. I have an automatic transmission. Immediately before the rear wheels can slide out, the ecu closes throttle or apply brakes or both. I can't tell because it's happening so fast. The rear end literally starts to move to the side and then a power reduction. I wonder what would happen without that safety net. Not really but you know what I mean. I dont want wheels sliding out on the interstate at that speed. This was with DSC/DTC off. Has anyone else had that experience?

[paradoxical3]

Originally Posted by brakthru

How much power and torque do you think you are pushing? The reason I ask is because I recently updated to an e60 tune with jb4 which causes wheel slip when I punch it even when I'm already going 65mph in a straight line. I have an automatic transmission. Immediately before the rear wheels can slide out, the ecu closes throttle or apply brakes or both. I can't tell because it's happening so fast. The rear end literally starts to move to the side and then a power reduction. I wonder what would happen without that safety net. Not really but you know what I mean. I dont want wheels sliding out on the interstate at that speed. This was with DSC/DTC off. Has anyone else had that experience?

I am putting down between 400 and 425whp, but in track trim it is probably closer to 375.

I might have found two parameters that will enable the e-diff to be coded on and off. They are:

E84_AX_REF_DIFF_LOCK

and

DIFF_Lock

I will try coding these out and then on my track day on Friday see if it changes anything.

[lowbudgethero]

Originally Posted by paradoxical3

I'm guessing you'd lose ABS, and I'd rather not do that since the car is a daily driver as well.

You would loose the auto brake force distribution as well which will help with braking as well, though it matters less on even well paved surfaces like a track.

Originally Posted by paradoxical3

I am putting down between 400 and 425whp, but in track trim it is probably closer to 375.

I might have found two parameters that will enable the e-diff to be coded on and off. They are:

E84_AX_REF_DIFF_LOCK

and

DIFF_Lock

I will try coding these out and then on my track day on Friday see if it changes anything.

You could pull the fuse for the system as well, makes it simple to reverse. You'll probably lose abs too however which will be pretty hard to adjust to.

[brakthru]

Originally Posted by paradoxical3

I am putting down between 400 and 425whp, but in track trim it is probably closer to 375.

I might have found two parameters that will enable the e-diff to be coded on and off. They are:

E84_AX_REF_DIFF_LOCK

and

DIFF_Lock

I will try coding these out and then on my track day on Friday see if it changes anything.

Good deal!

[Matticus91]

Originally Posted by paradoxical3

I am putting down between 400 and 425whp, but in track trim it is probably closer to 375.

I might have found two parameters that will enable the e-diff to be coded on and off. They are:

E84_AX_REF_DIFF_LOCK

and

DIFF_Lock

I will try coding these out and then on my track day on Friday see if it changes anything.

I'd really like to hear if this works out

[paradoxical3]

It worked. HUGE shout out to Alex at Alpine for doing the actual coding and staying late to help save my track day. There is also another value he coded out directly related to the brake disc too high, reduced power via DSC command.

It is a revelation being able to use the full mechanical LSD without ediff intervention. My brake pad wear also improved significantly. And most importantly, I did not get a single stored "reduced power via DSC command" code in the DSC module, and I got no power cuts on the track.

Alex had stupidly low prices too. Highly recommend you just pay him to have it done, it is the cheapest and best mod you will do for your car.

Also, why the heck has nobody figured this out before?

[dcaron9999]

Originally Posted by paradoxical3

It worked. HUGE shout out to Alex at Alpine for doing the actual coding and staying late to help save my track day. There is also another value he coded out directly related to the brake disc too high, reduced power via DSC command.

It is a revelation being able to use the full mechanical LSD without ediff intervention. My brake pad wear also improved significantly. And most importantly, I did not get a single stored "reduced power via DSC command" code in the DSC module, and I got no power cuts on the track.

Alex had stupidly low prices too. Highly recommend you just pay him to have it done, it is the cheapest and best mod you will do for your car.

Also, why the heck has nobody figured this out before?

Good work !!!

Can Alex manage to package this somehow, or sell his know-how to PTF (ProTuningFreaks)? Would love to be able to code changes via Cobb AP3 device in a custom map, or as an option.

Those of you with the know-how and a functional INPA may be in luck too.

[brakthru]

Originally Posted by paradoxical3

It worked. HUGE shout out to Alex at Alpine for doing the actual coding and staying late to help save my track day. There is also another value he coded out directly related to the brake disc too high, reduced power via DSC command.

It is a revelation being able to use the full mechanical LSD without ediff intervention. My brake pad wear also improved significantly. And most importantly, I did not get a single stored "reduced power via DSC command" code in the DSC module, and I got no power cuts on the track.

Alex had stupidly low prices too. Highly recommend you just pay him to have it done, it is the cheapest and best mod you will do for your car.

Also, why the heck has nobody figured this out before?

Awesome work man! I hope to get this done on my 335i soon. The parameters should be the same on my car too I hope. This has to be the single best discovery in a long time concerning traction control. So, how does the car feel with just the real LSD working? Are you putting more power down? I'm sure drifting is a bit easier now with both wheels trying to equalize torque and wheel spin as much as possible. Powering out of corners has to be awesome now. I'm sure you notice a slightly different drive on spirited daily driving too. Thank you for the update.