DCT in the snow

[Ducfan]

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Really want to check DCT this time around just for something different. M3 is my daily driver and it's generally a blast in snow. But occasionally the deep stuff posses some challenges that I struggle to see myself navigating without a clutch pedal.

Like to hear from anyone who's switched from MT to DCT in snow country.

[jackkk]

Originally Posted by Ducfan

Really want to check DCT this time around just for something different. M3 is my daily driver and it's generally a blast in snow. But occasionally the deep stuff posses some challenges that I struggle to see myself navigating without a clutch pedal.

Like to hear from anyone who's switched from MT to DCT in snow country.

Hi, I'm from Moscow, Russia. I got the 1M MT and just ordered the M3 DCT.
There are a lot of people here in Moscow and in St. Petersburg that have M3e92 DCT and have no problem with it all aruond the year.

[ChrisK]

I drive my e92 M3 DCT in snow - no problems all all.

[mkoesel]

I made the switch fairly seamlessly in 2008 when I went from an E46 M3 6MT to and E93 M3 M-DCT.

Without more detail, I am assuming your fears are in the area of being able to switch quickly between first gear (or any forward gear, technically) and reverse in the event you get stuck and need to rock the car back and forth to get loose. Is that your primary concern? If so, be assured that you can easily do that with the DCT. It lets you switch between the two quick enough such that the revs don't drop too much in between shifts. I became stuck in a deep snow drift over my street once earlier this winter and was able to use this technique to free the car.

Also, be aware that the DCT will let you put the car in neutral any time you wish. While stopped you just click the lever to the left, and while moving you just hold it to the left for a moment. You can rev the engine up and drop it back in gear though I can't say I have experimented with this enough to know all of the limitations. I am sure that if you do it from a stop it will cut revs before engaging one of the clutches. So it does have a number of measures to prevent you from doing high RPM clutch-drops but I've not found myself in a situation yet where I needed to be able to do that.

Overall it's a very robust transmission and shifting interface combination.

Originally Posted by Ducfan

Really want to check DCT this time around just for something different. M3 is my daily driver and it's generally a blast in snow. But occasionally the deep stuff posses some challenges that I struggle to see myself navigating without a clutch pedal.

Like to hear from anyone who's switched from MT to DCT in snow country.

[soccer dad]

I get a trip out of mkoesel's mod list in the sig every time I see it! I know I'm new, but I'm just saying!!!!

[Ducfan]

Thanks all, that's encouraging. Now I just have to decide that DCT is the type of fun I want....versus MT

[Alessandro]

dct in canada no issues, didnt get stuck once of course good wintertires is a must

[signes]

Drove an E46 with SMG through 5 winters without issue, including some bad storms. I prefer the feeling of more control a manual gives, but having a DCT will not give you any issues.

[MRV99]

I think the DCT in the snow is very good. I would not worry about doing a neutral to gear to get revs. I find the the MDM is great int eh snow. Gigs you some wheel spin and drifting ability to get going and get around a corner when you pushing through. You can also turn of tracking control completely if you are looking for unlimited amount of wheel spin. The only disadvantage I can say is you cannot easily put the car in N In a situation where you want to disconnect the motor from the driveline(motor drag causing the wheels to slide in icy or slick condition).

[jeff4598]

Snow tires/80 lbs salt in trunk(improves weight balance and handling on dry roads)/ traction control off/DCT-floored it and got unstuck with snow two inches above front bumper- of course tore up underbody shields but thats una voidable.

[Ducfan]

I didn't even think to mention it but yes, I always run winter tires in the winter. I've just not lived with a DCT yet and was interested in direct comparo of tranny given all else equal.

Couple things made me wonder...for one I can't stand the traction control in any setting on my e90 M3 either on snow or dry pavement. Find it much easier to find traction and make progress with it completely off. But there can be no completely off with DCT right? Somewhere a computer is deciding how to engage clutch, always.....isn't there?

Btw to any that don't think of the M for winter.....my M3 on winters is as good or better than my wife's X5 on no-seasons, save for maybe a deep drift where clearance gets me. And a lot more fun.

[filip75]

Originally Posted by jackkk

Hi, I'm from Moscow, Russia. I got the 1M MT and just ordered the M3 DCT.
There are a lot of people here in Moscow and in St. Petersburg that have M3e92 DCT and have no problem with it all aruond the year.

Moscow is stop-n-go traffic most of the time. So you end up driving in the slush, instead of powder.

[mkoesel]

Originally Posted by Ducfan

Couple things made me wonder...for one I can't stand the traction control in any setting on my e90 M3 either on snow or dry pavement. Find it much easier to find traction and make progress with it completely off.

You've got some nerves of steel if you are going TC-free in the winter. I do that when I want to be a teenager for a minute in a parking lot, but don't think I have the guts to drive in traffic without DCT on.

But there can be no completely off with DCT right? Somewhere a computer is deciding how to engage clutch, always.....isn't there?

To the best of my knowledge, the traction control system does not make use of the transmission, just the throttle and brakes. The only time the car holds both clutches open that I know of is when you've come to a complete stop. When driving - DSC on or off - you'll never be in a situation where the engine is disconnected from the wheels (unless you shift to neutral on your own accord).

[CanAutM3]

Originally Posted by mkoesel

You've got some nerves of steel if you are going TC-free in the winter. I do that when I want to be a teenager for a minute in a parking lot, but don't think I have the guts to drive in traffic without DCT on.



To the best of my knowledge, the traction control system does not make use of the transmission, just the throttle and brakes. The only time the car holds both clutches open that I know of is when you've come to a complete stop. When driving - DSC on or off - you'll never be in a situation where the engine is disconnected from the wheels (unless you shift to neutral on your own accord).

When driving in very slippery conditions and abruptly lifting off the throttle, the engine compression can cause the rear wheels to lock-up. In such a case I have experienced the DCT to disengage both clutches.

When there is a significant amount of snow on the ground, I also preferred to drive with DSC off. DSC would just slow the car down too much. Since I had my car coded with Euro MDM, I find it, combined with DCT in S2, to be the Goldilocks setting for winter. Just enough leeway and tire spin to get good traction and be able to slide the tail into position while maintaining a safety net.

[mkoesel]

Originally Posted by CanAutM3

When driving in very slippery conditions and abruptly lifting off the throttle, the engine compression can cause the rear wheels to lock-up. In such a case I have experienced the DCT to disengage both clutches.

Interesting you mention that situation because I had that happen to me a few times this winter and did not notice the clutches disengage. Instead I noticed the car get all squirrelly (oh shit!) and then settle once the the engine speed caught up. Gotta believe the automatic braking application of the DSC saved me there before the clutch ever needed to be disengaged. Certainly possible though, and I admit I hadn't thought of this scenario with my initial post.

Maybe it's the higher slip angles allowed by MDM that more commonly leads to this scenario. I do know the car will disengage the clutches if it spins, or probably even if it thinks a spin is about to occur.

When there is a significant amount of snow on the ground, I also preferred to drive with DSC off. DSC would just slow the car down too much.

I must be accustomed to it I suppose, because I never find it slowing me down. I've experimented with trying to get better launches from a stop with it off but was never able to do appreciably better, so I figure it's easier to just leave it on. And while moving, I can't imagine doing half of the high speed maneuvers I do in snow if I turned it off. I've gotten very used to being able travel over snow packed highways and expressways quickly to move around the excruciating slow herds of traffic. It kicks in all the time, and though I realize that means I am technically driving in a less than proper manner, I have come to use it to my advantage. Perhaps not a good habit, I realize, but what can I say.

Since I had my car coded with Euro MDM, I find it, combined with DCT in S2, to be the Goldilocks setting for winter. Just enough leeway and tire spin to get good traction and be able to slide the tail into position while maintaining a safety net.

I should turn in my man card for not having MDM of any sort. By the time the wizards of M3Post finally figured out how to do retrofits for non-iDrive MDrive, I just didn't feel I'd own car long enough to really justify it. I guess it's just me being lazy. Maybe I'll jump on it this summer if I feel the need to tinker.

[stressdoc]

Back on point here: I am considering DCT, but winter driving is a big ? for me. I need the nuanced feel from a clutch to get at just the exact point where tires are going to lose traction. I need to disengage/engage power to the wheels instantly and exactly the right amount.

[Ducfan]

Originally Posted by mkoesel

To the best of my knowledge, the traction control system does not make use of the transmission, just the throttle and brakes. The only time the car holds both clutches open that I know of is when you've come to a complete stop. When driving - DSC on or off - you'll never be in a situation where the engine is disconnected from the wheels (unless you shift to neutral on your own accord).

I guess this is what I'm curious about and can't quite come to be comfortable just how DCT is intervening and when. I seems it would have to disengage clutch before coming to a stop...I.e. Or engine would need to approach zero rpm just before the stop - which doesn't seem right. Without traditional torque converter it would have to be a trans computer issued commanded based on wheel speed, throttle and brake etc etc......I would think??

[CanAutM3]

Originally Posted by Ducfan

I guess this is what I'm curious about and can't quite come to be comfortable just how DCT is intervening and when. I seems it would have to disengage clutch before coming to a stop...I.e. Or engine would need to approach zero rpm just before the stop - which doesn't seem right. Without traditional torque converter it would have to be a trans computer issued commanded based on wheel speed, throttle and brake etc etc......I would think??

I have had my E92 DCT M3 through 6 Canadian winter with no issues. It drives perfectly fine. Don't worry.

[mkoesel]

Originally Posted by Ducfan

I guess this is what I'm curious about and can't quite come to be comfortable just how DCT is intervening and when. I seems it would have to disengage clutch before coming to a stop...I.e. Or engine would need to approach zero rpm just before the stop - which doesn't seem right. Without traditional torque converter it would have to be a trans computer issued commanded based on wheel speed, throttle and brake etc etc......I would think??

The transmission control unit is indeed made aware of the drive wheel speed (or at least output shaft speed) and automatically disengages the clutches once you've come to a stop. It also downshifts for you if you don't do so yourself (I almost always do, however) when you reach a sufficiently slow speed so as to avoid under rev and subsequent stall. It's very good at these two things, by the way (though the original software did have bugs in this area). I've never had the car stall, but at the same time, never had it fail to give me control of the drive wheels the moment I ask for it. These features are not technically related to DSC but I can understand why they are an area of concern for those who are coming from a manual transmission, especially in the context of low traction situations.

[bing240sx]

didnt read all responses but i'll counterpoint those who are supporting DCT in the snow.

DCT is drastically inferior to MT in the snow for very low traction situations.

I am in Canada and have Blizzaks and no i havent been stuck even once in the car in the two winters that i've driven it like this but MT still provides more control over the car and this will be most evident at a stop if you need to rock the car back and forth.

In an MT car you can really rock the car with the clutch and feel everything. Not only does the DCT not give you the same feel and response but if you have the door open and or no seatbelt while rocking the car (which is sometimes necessary) you will not be able to get the car in gear in this situation. the car will stay in neutral and if it does go into gear it will immediately go back into neutral.

maybe there is a way to override this with some custom coding but when i first got the car (in December) and before i put the Blizzaks on i found this very frustrating just trying to move the car around in the driveway in modest snow.

now that doesnt mean DCT isn't totally drivable in the winter, it is if you have good tires and are a good driver, but DCT does have its limitations compared to a MT in some cases.

That said, DCT is still the way to go on the car and this is coming from someone who was an ardent MT driver prior to this... the E9X M3 is the first non MT car i have ever bought and i will be staying with DCT on each M3 in the future.

[Benjamin]

with snow tires you'll be fine get something like blizacks. A good traction control system helps a lot along with stability control the car will be like magic.

[Powerslide]

Just coming off the second most snow for a single winter season in Chicago recorded history - DCT handled it like a champ!!! Still need to have snow tires and exercise common sense, but that being said, you truly need to have very deep snow and almost sheer ice before you'll have any problems!