Intrusive traction control on the X1

[ddark13]

It's not since my experience with a G35 coupe that I've seen a traction control system so willing to cut power. Since the G35 was RWD and not very refined in general, I thought it was excusable... but the X1 has a full time awd system and shouldn't have any problem putting power down.

When accelerating hard from 10-40mph, 1/10 times it'll shut things down. So, every time I'm about to merge I have to shut off traction control and then turn it on eventually, its not very convenient. Even when accelerating at a sane rate... I see the traction light flickering on and off every so often.

Has anyone else notice this? Have new tires helped or is the only answer shutting off traction control each time?

[paradoxical3]

Originally Posted by ddark13

It's not since my experience with a G35 coupe that I've seen a traction control system so willing to cut power. Since the G35 was RWD and not very refined in general, I thought it was excusable... but the X1 has a full time awd system and shouldn't have any problem putting power down.

When accelerating hard from 10-40mph, 1/10 times it'll kick it'll shut things down. So, every time I'm about to merge I have to shut off traction control and then turn it on eventually, its not very convenient. Even when accelerating at a sane rate, I see the traction light flickering on and off every so often.

Has anyone else notice this? Have new tires helped or is the only answer shutting off traction control each time?

All season tires?

X drive or not, 300lbft torque kicking in at low RPM is going to roast all seasons.

Also, you're in NYC - could be the potholes. If the system detects wheel slip (which happens over big potholes) it will cut power.

[nospam]

I'm willing to bet you have all-season tires. I have yet to see the DTC light flicker.

[Grovsnus]

Originally Posted by nospam

I'm willing to bet you have all-season tires. I have yet to see the DTC light flicker.

The 28i might be different from the 35i then.
It cuts in an awful lot for me - if I ever try to go from coasting to full power, it will predictably turn on. With high performance summer tires. On a dry day, on good roads. It doesn't even try to increase the speed before it cuts out, so it's not that the wheels are slipping, more that the programming think they might.

It's downright dangerous how it cuts the power for 2-3 seconds after I go to the left lane to pass someone. In the mean time, the car behind me has filled the gap, so I can't get back in.
It's so bad that I turn the DTC off unless it's raining. For safety.

[JL350]

I don't think I have had traction control kick in, certainly did not notice. Maybe because I have a diesel, and always drive in sport mode. If it was me I would check tyres and tyre pressure, I run 36 to 37 psi, too high a pressure or uneven pressure may cause issues....

[Grovsnus]

Originally Posted by JL350

I don't think I have had traction control kick in, certainly did not notice. Maybe because I have a diesel, and always drive in sport mode. If it was me I would check tyres and tyre pressure, I run 36 to 37 psi, too high a pressure or uneven pressure may cause issues....

Not to be unkind, but how you experience traction control in a 181 hp 20d is not really relevant to the 300 hp 35i which accelerates around 58% faster.

Tire pressure is just fine. I think it's more that the DTC programming is too generic and a single program has to deal with both 17" winter tires and 19" high performance summer tires, and with a higher powered model like the 35i, this can cause problems.

The funny thing is that I can get the wheels to spin from a standstill, or by turning while gradually increasing rpm, without the DTC kicking in until after the fact, but if I'm rolling at around 40-50 mph and put the foot down, it immediately will cut power for 2-3 seconds.

[nospam]

2-3 secs is a problem. I have BMS Stage 1 on my x28i and came from an N54 335i. In the 335, DTC would often cut in when accelerating on a bad road but not for more than a second.

2-3 secs on an AWD vehicle is pretty ridiculous.

Are 35i M Sport owners with Performamce Control experiencing a problem?

[Mr Mech]

This is somewhat disapointing. I am in a 335i now, and traction control is horrible off the line. I was hoping the AWD system would fix it, but it sounds like its even worse.

My traction control won't kick in from a roll unless I hit a bump or something that breaks the wheel loose. Doesn't make sense that AWD would be worse. Is this something that can be reprogramed at the dealer?

[bimmerfile]

From the sounds of it, I'm fortunate to have gone with the 2.8i.

[Grovsnus]

Originally Posted by nospam

2-3 secs is a problem. I have BMS Stage 1 on my x28i and came from an N54 335i. In the 335, DTC would often cut in when accelerating on a bad road but not for more than a second.

2-3 secs on an AWD vehicle is pretty ridiculous.

Are 35i M Sport owners with Performamce Control experiencing a problem?

To be honest, the 2-3 seconds could be because the first two seconds I go WTF, too flabbergasted to lift my foot from the pedal.
Who needs ECO PRO when the DTC already prevents you from accelerating hard? In a Merc, I would expect nannyware that protects the user from things like accelerating "too" hard or auto-braking if you refuse to brake for dust devils and leaves, but I don't think these "features" belong in "The ultimate driving machine".
Good thing the off buttons for ECO PRO and DTC are in vicinity of each other.

[Red Bread]

Interesting, I have noticed very limited DTC interference on our 35i with the less than stellar Pirelli P7 A/S's. It's much, much better than our previous 1 wheel drive 135i with either the Bridgestone RE050's or the non RFT Michelin Pilot Sport A/S tires it had. That thing required instant disabling of the DTC if you really wanted to get anywhere.

[eric9610]

I have the the 35i and i drive the car very hard with no DTC coming on. i think you may have an issue with your programing. i would go to the dealer and ask them to reprogram the car.

[M3tallicar]

Originally Posted by eric9610

I have the the 35i and i drive the car very hard with no DTC coming on. i think you may have an issue with your programing. i would go to the dealer and ask them to reprogram the car.

Haven't noticed it cutting out either and I drive with paddles in sport mode all the time in a bad for gas mileage way on cruddy city streets. Have M Sport and 19" P Zero summers

[Bmwdriver22]

Mine cuts out intermittently ... Dealer said it was ok but I disagree... I'm in msport 35i and am missing the paddles for unknown reasons

[CIWS]

Originally Posted by Bmwdriver22

Mine cuts out intermittently ... Dealer said it was ok but I disagree... I'm in msport 35i and am missing the paddles for unknown reasons

When I was buying the dealership had two MSports there, neither had paddle shifters. So I got the Sport that did

[Grovsnus]

Originally Posted by Bmwdriver22

Mine cuts out intermittently ... Dealer said it was ok but I disagree... I'm in msport 35i and am missing the paddles for unknown reasons

Based on the responses here from various people, I'm thinking it might be an 35i M-Sport related issue.
The M-Sport allegedly has a 20:80 front:rear torque bias and stiffer suspension, while the non-M-sports has a 40:60. It could be that flooring it makes the DTC's proactive program -- which likely is the same for all models -- draw the wrong conclusion.

The DTC also knows nothing about the tires, and if it uses the same proactive programming as for the models with AS tires, it probably kicks in too soon when using high performance summer tires.

in any case, I wish there was a way to disable the proactive aspect of the DTC, while keeping the reactive. Or have it react to the front wheel traction only.

[Red Bread]

The 20/80 split for M Sport is just misinformation. It is the same 40/60 split but all can transfer as much as 80 percent to the rear.

[Grovsnus]

Originally Posted by Red Bread

The 20/80 split for M Sport is just misinformation. It is the same 40/60 split but all can transfer as much as 80 percent to the rear.

Got any references for that? Back when you were only "unconvinced", I provided you with plenty of references for the 20:80 split. Why do you now claim it's misinformation?

[Red Bread]

Originally Posted by Grovsnus

Got any references for that? Back when you were only "unconvinced", I provided you with plenty of references for the 20:80 split. Why do you now claim it's misinformation?

Even your references are confused. Some quote a constant 20/80 and some reference an ability to send as much as 80% to the rear under cornering conditions.

The X1 is a parts bin car (I owned the original M Coupe, I know parts bin cars) and I find it extremely unlikely that BMW would develop and implement a new technology on a car that is e-chassis based and that has many other compromises like the 6s in the 35i.

If it was indeed a fixed 20/80 split, it would be unique in the BMW world, more aggressive than the M135i with xDrive, the M550d and even the X5M and X6M.

In every line of BMW's that offers "Lines" the M Sport is cosmetic. It's cool that the X1 actually gets torque vectoring over the other lines, but I do not believe it gets a different torque bias. If this were the case, shouldn't it have beefed up hardware to cope with such a change? Shouldn't BMW clearly notify buyers that if they live in the snow belt, they may want to strongly consider avoiding the M Sport package? Shouldn't BMW find a way to tout this unique and interesting technology? They don't because all it is a misunderstanding of the ability of xDrive (in any current xDrive vehicle) to transfer as much as 80% to the rear wheels in conditions where there is slip.

Ultimately, I think what is probably being confused is that Performance Control may indeed automatically send 20% more power to the rear in cornering conditions, instead of the non PC system retaining 40/60 until there is slip. However this is not the same thing as a steady state 20/80 split. I still think this is something that should both be marketed and communicated to buyers in the snow belt, if it is indeed the way PC works.

[eric9610]

I have not read one article that states torque vectoring is only available on M-Sport models. Everything i have seen shows that all xdrive models have torque vectoring allowing 100% of power to be sent to either the front or rear axle while the breaking system controls what wheels get the power on the axle.

[dgkli]

Originally Posted by Red Bread

Ultimately, I think what is probably being confused is that Performance Control may indeed automatically send 20% more power to the rear in cornering conditions, instead of the non PC system retaining 40/60 until there is slip. However this is not the same thing as a steady state 20/80 split. I still think this is something that should both be marketed and communicated to buyers in the snow belt, if it is indeed the way PC works.

http://www.bmw-xdrive-guide.com/xd_e...ive_technology

I don't think this directly answers the question, but I thought this was a very interesting animation. It refers to Dynamic Performance Control, not Performance Control, but still it implies a very dynamic reactionary nature for xDrive, (which suggests that even if it were true that the "default" mode were 20:80 rather than 40:60, it might not be of concern in icy conditions, for example).

[dgkli]

Originally Posted by eric9610

I have not read one article that states torque vectoring is only available on M-Sport models. Everything i have seen shows that all xdrive models have torque vectoring allowing 100% of power to be sent to either the front or rear axle while the breaking system controls what wheels get the power on the axle.

I infer that the difference with "Performance Control" is that not only is torque vectoring reactionary to available traction at each wheel, but it also is done based on turning angle, that is, the inside rear wheel is braked a bit to assist turn-in/reduce understeer, as the car is turning (not directly related to the traction at each wheel).