[pkim1079]

Originally Posted by elistan

I *think* this is how it works, based off the not-too-clear owner's manual:

Default mode upon startup: DSC (Dynamic Stability Control) mode
Traction control is enabled (ie, limiting drive-wheel spin via throttle control and/or brake application)
Stability control is enabled (ie, controlling under- and over-steer by applying brakes to individual wheels)

Hitting the DSC button once: turns on DTC (Dynamic Traction Control) mode
This mode appears to disable the "helps to keep the vehicle on a steady course" aspect of DSC - the under/oversteer control bit. Traction control is still enabled, and sounds like the car won't engage individual brakes to correct yaw movement. Somehow this is supposed to help with getting/staying moving on unplowed snowy roads, gravel roads, and the like. Probably because in such low-traction conditions, there's so much slippage that DSC would be constantly engaging, to the detriment of actually getting anywhere.

Holding the DSC button for 5-10 seconds: turns on DSC OFF mode
"Stability is reduced." But the manual also says "the DSC system is switched off." So I'm not clear to what degree the nannies are deactivated, but the implication is that both traction and stability controls are effected.

Then there are the driving modes:
ECOPRO, COMFORT and SPORT are known.
SPORT+ isn't clearly described in the manual. "Limited driving stabilization. The driver handles several of the stabilization tasks." It also illuminates the DSC OFF indicator, same as the 5-10 second button press. The implication, in my mind, is that SPORT+ accomplishes exactly the same thing in terms of stability/traction control as the 5-10 second button press. (Whether that's completely off, or just partially off, the stability programs I don't know. I haven't had the opportunity in an obstruction-free parking lot to test these modes.)

I think sport+ is sport plus DTC on. no?

[SamS]

Originally Posted by pkim1079

I think sport+ is sport plus DTC on. no?

Right, Sport+ is DTC turned on, DSC still on as well.

DSC (and no DTC) = full nanny mode
DTC = some wheel spin

[pkim1079]

Originally Posted by lukeb817

Closer? It's clearly a different sound...there is no question that there is no burble in comfort and there is significant burble in Sport. Why do you think Challenge even did the comparison in the video in the first place?? It was to compare the sound between comfort and sport/sport+ ...to illustrate how the sport/sport+ burble sounds with that exhaust. Maybe it's not as pronounced in the N20, but it's a very noticeable difference in sound on the N55 when switching from comfort to sport/sport+.

the other car in my garage is a 135i. Non sport mode - you get the same power / acceleration but the damn traction control kicks in and its just a big herky jerky launch. With sport mode on it lets you lose more traction and doesn't cut in. Same power, same delivery, same note.

Are you saying in sport mode the car runs more rich?

[elistan]

Originally Posted by pkim1079

I think sport+ is sport plus DTC on. no?

The manual isn't clear on this. Upon re-reading it, however, I'm now leaning towards thinking that yes, you're right, SPORT+ is SPORT plus DTC, meaning the stability program is disabled but traction control is still active. Which is sad, because it'd be great to be able to get power-slides in SPORT+. (Although maybe that's not possible anyway due to the open diff, so power slides aren't possible even in DSC OFF mode, just a whole lot of inside wheel spin?)

I'll amend my above post appropriately.

[elistan]

Originally Posted by SamS

Right, Sport+ is DTC turned on, DSC still on as well.

DSC (and no DTC) = full nanny mode
DTC = some wheel spin

Actually, I think DTC equals no correction of under- or over-steer conditions, but it'll still cut engine power or apply brakes to stop wheel spin due to power application.

[SamS]

Originally Posted by elistan

Actually, I think DTC equals no correction of under- or over-steer conditions, but it'll still cut engine power or apply brakes to stop wheel spin due to power application.

That's not really correct, IME. With DTC on, you can still break the rear end loose, but not completely spin out. The car monitors your steering angle, speed and such and will let you slide, but not spin out. Over steer is definitely possible.

[tdizzle]

Originally Posted by SamS

That's not really correct, IME. With DTC on, you can still break the rear end loose, but not completely spin out. The car monitors your steering angle, speed and such and will let you slide, but not spin out. Over steer is definitely possible.

Random Note:
The car wont prevent you from being bonkers, even in comfort on wet pavement you can spin the wheels from a stop or make the car get sideways pretty easily (70% throttle). Traction control with flash and yell at you but the rpms hitting 5-6k with the car barely moving was an interesting thing I noticed. I dont think it cuts engine power, but brakes the appropriate wheel and tries to get traction to get you going in the right direction.

I wasn't trying to do anything crazy but the streets were a bit wet and I turned onto another street and gave it about medium throttle (in comfort mode) and the wheels spun pretty easily. Obviously, this was mostly due to wet pavement but still...

To get the same reaction you'd have to turn it to sport + and really get on it, but it's still possible to break the tires loose without power breaking.

/end obvious post

[lukeb817]

Originally Posted by pkim1079

the other car in my garage is a 135i. Non sport mode - you get the same power / acceleration but the damn traction control kicks in and its just a big herky jerky launch. With sport mode on it lets you lose more traction and doesn't cut in. Same power, same delivery, same note.

Are you saying in sport mode the car runs more rich?

All I know is there is a very noticable difference in the sound of the exhaust on the F30 N55 when switching from Comfort to Sport/Sport+...I always noticed it from the very beginning, but once I got the M Performance exhaust I could REALLY hear it (much like the Challenge video, above). I hear it when revving and letting off the gas as well as some engine braking situations. Since overrun burble is the sound of unburnt fuel igniting and popping in the exhaust system, clearly the car is delivering extra fuel on overrun that it doesn't in Comfort mode. Now, it's certainly possible that it's just a change in the fueling on overrun after lifting off the accelerator, and isn't changing the mixture/mapping at any other point in the engine operation and is merely a superficial change to make Sport/Sport+ "feel sportier" based on the exhaust note. My original question was whether or not it has been substantiated that the perceived perfomance change in Sport was merely a result of less linear throttle response or if more was going on, which is why I brought up the exhaust burble in the first place...since that is clearly a result of a change in fuel mapping, at least on overrun.

Regarding the 135i, one of the features of the PPK for the N55 E90 and 135i was the addition of exhaust overrun burble sounds. In the long F30 N55 PPK thread (Here), there was a 135i owner who commented that his 135i originally had the pronounced overrun burble sound, but after the PPK was released, and his car received subsequent software updates, the burble went away...he posited the conspiracy theory that once the PPK was on the market, BMW eliminated the burble on the 135i through software updates to get people to pony up for the new PPK since the burble sound was touted as a benefit of the PPK upgrade (here is his post)

[HighlandPete]

Originally Posted by elistan

The manual isn't clear on this. Upon re-reading it, however, I'm now leaning towards thinking that yes, you're right, SPORT+ is SPORT plus DTC, meaning the stability program is disabled but traction control is still active. Which is sad, because it'd be great to be able to get power-slides in SPORT+. (Although maybe that's not possible anyway due to the open diff, so power slides aren't possible even in DSC OFF mode, just a whole lot of inside wheel spin?)

I'll amend my above post appropriately.

Not how BMW describe the Sport+ function. DTC is a function within DSC, and is activated in Sport+. Giving more freedom for wheel spin, but DSC is still active to mop up the mistakes.

This is BMW description for the F10. Sure it is the same in the F30.

Another button clearly recognisable by a pictogram symbolising the reduction of stability enables the driver to choose the appropriate DSC setting. As an example, he may activate a special traction mode for starting off and driving more easily on loose sand or in deep snow. This is done by DTC Dynamic Traction Control, a special mode of DSC, raising the response thresholds in Driving Stability Control. The DTC function for Driving Stability Control is also activated in the SPORT+ mode, intentionally allowing slight slip on the drive wheels in order to take bends in a controlled power slide.

In the F10 User Manual

Activating SPORT+
Press the button repeatedly until SPORT+ appears in the tachometer and the DSC indicator lamp lights up in the instrument cluster.

Indicator/warning lamps
SPORT+ is displayed in the tachometer. The indicator lamp lights up: DTC Dynamic Traction Control is activated.

HighlandPete

[RPM90]

Originally Posted by HighlandPete

Not how BMW describe the Sport+ function. DTC is a function within DSC, and is activated in Sport+. Giving more freedom for wheel spin, but DSC is still active to mop up the mistakes.

This is BMW description for the F10. Sure it is the same in the F30.



In the F10 User Manual



HighlandPete

This is how it worked in my 135i and how it's described to work with the F30.
DTC is "dynamic traction control", key word is "dynamic".
DTC is part of DSC. When DTC is engaged it allows wheel spin and rear end out to a greater degree before DSC steps in.

For practical purposes engaging DTC (pushing DSC button once) can help the car get unstuck if it's in snow and you need wheel spin to get the car out.
For fun, DTC (with either one push of DSC or sport+ engaged) allows the drive tires to spin on a hard launch as the ECU won't cut throttle in order to regain traction.
DTC also allows the driver to have some fun with a bit of "drifting".
It's not at the same level as turning DSC completely off as DTC will still intervene by braking and/or throttle cut if the rear swings past a certain degree.

DSC completely off will turn traction and stability completely off. This is the mode for experienced drivers as any mistake can't be helped by the stability system.

With my 135i this was easy to understand. If I want some wheel spin and some drift angle, but also have DSC step in if things get too far, then press the DSC/DTC button once and engage DTC. The rest of the car; steering, throttle stay as they are, as there was no choice. I had an MT 135i.
If I wanted full control and no stability ECU intervening, then I push the DSC button for at least 5 seconds and it's all off.

The F30 confuses the use of DSC and DTC as it ties drivers modes with it. If I'm in sport mode and I hold the DSC button, "DSC OFF" will light up on the dash. If I then turn DSC back on, drivers mode looks like it drops down to "comfort" mode, instead of staying in sport mode. Really odd.
Makes one wonder if they are still in sport mode if they turn DSC off while in sport mode. ARRRRGH!

When I'm in sport mode and turn DSC off it does feel as if I'm still in sport mode. BUT, my AT operation suggests otherwise, because once DSC is turned off, and I'm in sport mode, the trans will shift to 7th and 8th, which it won't do when driver mode is in sport. Conf*ckingfreakingfusing.

More testing is in order as I'm still not 100% positive what happens when I'm in sport driver mode and I manually turn DSC off.

[pkim1079]

in comfort - DSC is ON (DTC is off) - this cuts in to all the wheel spin
when activating DTC (DTC ON) - this allows some wheel spin but still has DSC engaged in case some sort of mishap.

I think the confusion is where DTC ON means MORE wheel spin, not less wheelspin.

[bimmerjph]

Press Once- Deactivates DSC, Activates DTC
Hold for 5 Seconds- Deactivates DSC and DTC, Simulated LSD stays on (eLSD)


So technically you can't turn it off, but the system is not going to prevent the car or both ires from spinning. All it will do is make try to make sure that one single wheel is not spinning.

[HighlandPete]

Originally Posted by bimmerjph

Press Once- Deactivates DSC, Activates DTC

No, that is not correct. As many posts have stated, DSC remains on with DTC activated.

We must view DTC as a version of DSC, within, or sub-function of DSC.

Quoting BMW:

The DTC also makes driving on snow and ice-free roads more dynamic. When activated, the DTC allows sporty drivers more room to manoeuvre around curves than the Dynamic Stability Control and even permits controlled drifts. The driver retains complete control over the vehicle in every situation and the Dynamic Stability Control’s stabilising measures remain active even when the DTC is activated.

HighlandPete

[woderd]

How can there be so much confusion with these damn modes?

Can someone explain what each mode is and how it can be activated/deactivated in one nice summery that everyone can agree on?

I seen someone tried to summarize but then another person said it was incorrect.

[Vitoco]

Originally Posted by woderd

How can there be so much confusion with these damn modes?

Can someone explain what each mode is and how it can be activated/deactivated in one nice summery that everyone can agree on?

I seen someone tried to summarize but then another person said it was incorrect.

What Bimmerjph wrote is WRONG, the other posts are correct.

DSC is always ON til you manually turn it off by pressing the button for a few seconds.

DTC is a mode that is always OFF unless you put in Sport+ or press the button once, then it is turned ON. (DSC is still ON)

DTC allows for some extra wheelspin but DSC is still there to cut in before it gets out of hand.

Anyone saying anything else than this, is wrong.

[elistan]

Originally Posted by woderd

How can there be so much confusion with these damn modes?

Because the owners manual is crap in this regard, IMO. It vaguely describes what the modes are intended to do, but doesn't say diddly about how this is actually achieved. For example, the DTC ON (ie, press the button once) section simply states:

"The DTC system is a version of the DSC in which
forward momentum is optimized.
The system ensures maximum forward momentum
on special road conditions, e.g., unplowed
snowy roads, but driving stability is limited.
It is therefore necessary to drive with appropriate
caution."

But what does that mean? I assumed it left traction control on to prevent wheel slippage during acceleration in slippery conditions, with yaw control being disabled, but some other forum members have stated that no, it actually is designed to allow for more wheel slippage during acceleration. WTF, BMW?

Can someone explain what each mode is and how it can be activated/deactivated in one nice summery that everyone can agree on?

I seen someone tried to summarize but then another person said it was incorrect.

That was probably me you're talking about - and after doing a little bit of testing at a stop sign on a section of road I know to be slippery, I've concluded that my summary based on reading the manual is meaningless.

[SamS]

Originally Posted by Vitoco

What Bimmerjph wrote is WRONG, the other posts are correct.

DSC is always ON til you manually turn it off by pressing the button for a few seconds.

DTC is a mode that is always OFF unless you put in Sport+ or press the button once, then it is turned ON. (DSC is still ON)

DTC allows for some extra wheelspin but DSC is still there to cut in before it gets out of hand.

Anyone saying anything else than this, is wrong.

Yep. Read and repeat.

[bimmerjph]

Originally Posted by HighlandPete

No, that is not correct. As many posts have stated, DSC remains on with DTC activated.

We must view DTC as a version of DSC, within, or sub-function of DSC.

Quoting BMW:



HighlandPete

My bad. Thats how it is on the E46. I didn't know they changed it.

I believe I am still correct about the elsd though.

[ric124]

Originally Posted by bimmerjph

My bad. Thats how it is on the E46. I didn't know they changed it.

I believe I am still correct about the elsd though.

oh wait sport mode doesnt add 100hp like on the M5? my bad...LOL

I believe eDif is activated in Sport+ mode along with Launch control for those who have MT.

[bimmerjph]

Originally Posted by ric124

oh wait sport mode doesnt add 100hp like on the M5? my bad...LOL

It was like that for years and years on every model. I didn't know they had changed it. The F30 doesn't even have a power button, so your joke is pathetic. I was just trying to help. No need to be a dickweed.

[HighlandPete]

Originally Posted by bimmerjph

I believe I am still correct about the elsd though.

This is how BMW described the DSC-Off function for the F10. Not found a similar statement for the F30, others may have done so and can confirm if it is the same statement.

Keeping the additional button pressed down, the driver is able to fully deactivate Driving Stability Control. This DSC-Off mode activates an electronic locking function on the rear axle differential for a more sporting and ambitious style of motoring, for example when accelerating out of a bend or hairpin.

HighlandPete

PS: Added BMW quote for F30.

Dynamic Stability Control thresholds are raised and Dynamic Traction Control (DTC) is activated. It is also possible to shut off DSC altogether. The electronic limited-slip function for the rear differential can then provide extra-sporty acceleration out of corners or hairpins.

HighlandPete

[elistan]

Originally Posted by HighlandPete

PS: Added BMW quote for F30.

Where are you getting these descriptions? They're much more detailed than what the manual has!