[capt_and]

I was at the track this last weekend and had a few issues with the DSC. After over cooking a corner, I went to correct and felt the engine completely cut power and I saw a light flash. The result was the car spun out even though I would have been able to save it. Those who take their cars out to the track know the importance of maintaining throttle for corrective maneuvers. Without any use of the throttle, all I could do was try and correct via steering wheel and wound up doing a 180. This doesn't always happen though. There have been instances where I've been able to apply full power and save it. I had DSC turned off so I am wondering what this may have been.

[Dylan86]

I believe it's the ABS LSD kicking in, only thing that would explain such behaviour. That is the flaw with this system, it attempts to give you performance, by using brakes when you may not want this intervention during a power out or slide. I've felt it kick it a bit even with an LSD, and I'll be coding the e-lsd "OFF" next month.

My $.02

[aerobod]

Originally Posted by capt_and

I was at the track this last weekend and had a few issues with the DSC. After over cooking a corner, I went to correct and felt the engine completely cut power and I saw a light flash. The result was the car spun out even though I would have been able to save it. Those who take their cars out to the track know the importance of maintaining throttle for corrective maneuvers. Without any use of the throttle, all I could do was try and correct via steering wheel and wound up doing a 180. This doesn't always happen though. There have been instances where I've been able to apply full power and save it. I had DSC turned off so I am wondering what this may have been.

If power was cut, DSC won't have been off completely, possibly in DTC mode as opposed to DSC OFF mode (would still have the DSC OFF light illuminated). I've accidentally done this before, either forgetting to turn off DSC after an engine restart or not pressing the DSC OFF button long enough. Also, I think if you hold the DSC button down for longer than 10 seconds, DSC may not switch off as anticipated (says to not hold down the button longer than 10 seconds in the manual).

[cxp213]

I recall you posting not too long ago in this thread that you wanted all these electronic nannies on at track because some article said it was sophisticated and companies spent lots of money on them, lol. Are you starting to outgrow these systems now?

[Dylan86]

With "DSC" off, you will still get rear wheel ABS intervention due to the E-LSD programming.

[capt_and]

Yes, I 100% had DSC OFF illuminated on the dash. It wasn't the brakes coming on; the engine did not respond to throttle input. Maintenance throttle wasn't doing anything so I put the gas pedal all the way to the floor (just to see since I was about to spin anyways) and the tach didn't move.

Originally Posted by cxp213

I recall you posting not too long ago in this thread that you wanted all these electronic nannies on at track because some article said it was sophisticated and companies spent lots of money on them, lol. Are you starting to outgrow these systems now?

The m240i doesn't have very sophisticated nannies... The nannies on my 911 are much much better. I shaved off a couple seconds with them off; and reduced brake wear.

[XutvJet]

How much fuel were you running when this happened?

Any power mods?

[Poochie]

Originally Posted by Dylan86

I believe it's the ABS LSD kicking in, only thing that would explain such behaviour. That is the flaw with this system, it attempts to give you performance, by using brakes when you may not want this intervention during a power out or slide. I've felt it kick it a bit even with an LSD, and I'll be coding the e-lsd "OFF" next month.

My $.02

Please share the coding to do this when you can, I can't find the module in Bimmercode. Thanx!

[capt_and]

Originally Posted by XutvJet

How much fuel were you running when this happened?

Any power mods?

Stock power. The fuel is an interesting point. I never let levels get below 1/2 tank before going out. I’m going through 1/3 tank every 25 minute session so if it’s 2/3 tank then at the end of the session I’d have 1/3 left. Maybe that’s low enough to cause an issue? But, it’s happened middle of a session before so I don’t think that’s it. Fuel also doesn’t explain the flashing light.

[Dylan86]

If you run too low on fuel at the track (usually below 1/2 tank), you'll get a "fall flat on your face" effect, along with a "Drivetrain Malfunction" error, and will need to pull out, turn the car off, then on, to keep going.

FWIW, the ABS intervention also effects throttle input... You don't get GAS + BRAKE from any computer

[XutvJet]

Sounds like you may be over-driving the car. Perhaps slow it down a bit or buy stickier rubber. ABS intervention can hasten throttle response.

[cxp213]

Yeah, slow it down a bit, although buying stickier rubber may not be the answer if that's the case. Depending on how much stickier, it can give the inexperienced drivers a false sense of additional confidence, until it snaps back on them (at higher threshold and speed).

Originally Posted by capt_and

Maintenance throttle wasn't doing anything so I put the gas pedal all the way to the floor (just to see since I was about to spin anyways) and the tach didn't move.

Don't try to be a hero at these HPDEs. If you overcook a corner and are clearly about to spin, going WOT "just to see" may not be the smartest idea.

[CP911]

Sounds like you had entered DTC mode unintentionally or were in Sport +, which enables DTC anyways. When in DTC mode, the "DSC OFF" is displayed, but even when this is displayed, DSC is NOT actually disabled fully. You must hold the "traction off" button right above the "Sport/Comfort" toggle button for a few seconds to actually fully disable DSC aka all the nannies. If you were in a rush and didn't hold this button long enough, that means you effectively pressed it 1 time and entered DTC mode by accident. This would explain why you experienced what you did.

[capt_and]

Originally Posted by cxp213

Yeah, slow it down a bit, although buying stickier rubber may not be the answer if that's the case. Depending on how much stickier, it can give the inexperienced drivers a false sense of additional confidence, until it snaps back on them (at higher threshold and speed).


Don't try to be a hero at these HPDEs. If you overcook a corner and are clearly about to spin, going WOT "just to see" may not be the smartest idea.

Yes, I intentionally didn't get stickier rubber just so I could learn to drive with some slip and recover.

And to be clear, I do NOT push it at a DE. I am a member at MSR and there was nobody out there. The corner is question is Horseshoe, a relatively slow corner that was pretty slick that day. Please, for anybody reading this doing DEs, do not try to push it too hard. I had one other car on track at that time and he was a couple of turns ahead of me so I knew I had plenty of time. Again, do not over drive the car on a DE day, it's annoying for everybody. And don't do it on a public road either.

After some reflection, I think the ABS ediff explanation is probably the reason.

[Maynard]

This might also be part of the crash-survival package (DK the formal term for these) - IIRC, there are cutoffs that trigger at excessive g-loads to pull power, and this sounds a bit like that (sudden loss of throttle w/o obvious braking action). A sudden spin would presumably be something it would interpret as 'crashing' in road-car world.

[capt_and]

Originally Posted by Maynard

This might also be part of the crash-survival package (DK the formal term for these) - IIRC, there are cutoffs that trigger at excessive g-loads to pull power, and this sounds a bit like that (sudden loss of throttle w/o obvious braking action). A sudden spin would presumably be something it would interpret as 'crashing' in road-car world.

This makes a lot of sense. I think this may be it. I had no idea that this was a "feature". Is it possible to code out?

[Maynard]

I recall finding a fairly detailed and informative thread here about the many 'nannies' and how to code them off for track use (and their potential complications on track) - try searching to find that, and see if it is also discussing this 'crash -system'. I don't recall if they are all from the same source, and DK if those were s/t that could be coded out. They might simply involve accellerometers, kind of like the airbags.

[TajoMan]

After you turn off the DSC (by pressing the button and hold for 10sec), did you change the driving mode?
If you change driving mode to sport+ after you turn off DSC, it will come out of DSC off.
DSC off is kinda like it's own driving mode.
You cannot put your car in sport or sport+ with DSC off.

[capt_and]

Originally Posted by TajoMan

After you turn off the DSC (by pressing the button and hold for 10sec), did you change the driving mode?
If you change driving mode to sport+ after you turn off DSC, it will come out of DSC off.
DSC off is kinda like it's own driving mode.
You cannot put your car in sport or sport+ with DSC off.

I only run DSC off, no Sport or Sport+.