Does an M3 with SMG gearbox roll backwards on a hill?

[clk55pete]

I ask the question because my current car - a CLK55 AMG is, of course auto, and stays in Drive when stationary. I'm interested in getting a second car and thinking about an M3 at about the £10K mark. The issue is that I'm a wheelchair user and can’t use my legs at all so the car has to come without a foot clutch.

So to the question:

When stopped on a hill with a SMG box does it pop itself automatically into neutral? (and so the car role back unless you ride the accelerator or depress the brake?)

When moving off on a hill start does the car role back prior to your depressing the accelerator pedal or does the depression of the accelerator signal the gearbox to move into gear?

Any advice appreciated! I don't want to by a car that’s unusable to me. (I obviously can’t try one as I use hand controls).

[mat205125]

The SMG has a clutch rather than a torque convertor like your automatic.

When you stop, the car "pushes" the clutch in, as you would if there was a pedal, and the car remains in gear.

The car WILL roll if you let your foot off of the brake.

[john_p]

When stopped it stays in gear until you move off again. The only time it 'forcibly' drops into neutral is when you leave the door open for a while.

There is a "hill start" feature which you start by holding down the left paddle for a few seconds - this then holds the car on the clutch until you either brake or accelerate.

[clk55pete]

Thanks chaps. Just one more question: can you use the gearbox in tiptronic fashion? Ie touch the gearleaver right for up and left for down etc when in manual or tip mode or do you have to control the gears by the stearing wheel?

Edited by clk55pete on Monday 10th August 13:12

[Noel]

You can use the gear lever or paddles to change gear, I find a vary it, paddles when dead ahead or lever when on roundabouts etc. You can also use the 'hill start' facility which stops the roll but I've never bothered to remember it.

[Zod]

mat205125 said:

The SMG has a clutch rather than a torque convertor like your automatic.

When you stop, the car "pushes" the clutch in, as you would if there was a pedal, and the car remains in gear.

The car WILL roll if you let your foot off of the brake.

but at the same time, you can feel the clutch bite point through the accelarator, so it is really very similar to a conventional manual.

I swap daily between manual and SMG cars and for me SMG feels remarkably similar to a conventional manual.

[waremark]

Do you have a hand for the handbrake? When I used an SMG, I did not bother with the hill-start feature. I found it easier to use the handbrake in the same way as on a manual. On the other hand with my DCT M3 I regularly use the hill-start feature, which is quite different - when you take your foot off the foot brake, it keeps the brake applied for a couple of seconds or until you apply the accelerator.

You obviously have not tried an SMG car. It is very different from a conventional auto. You might like it or hate it. I strongly suggest that you at least get yourself driven in one before you consider it any more seriously.

[waremark]

By the way, why are you considering a second car which is quite similar?

[Zod]

waremark said:

Do you have a hand for the handbrake? When I used an SMG, I did not bother with the hill-start feature. I found it easier to use the handbrake in the same way as on a manual. On the other hand with my DCT M3 I regularly use the hill-start feature, which is quite different - when you take your foot off the foot brake, it keeps the brake applied for a couple of seconds or until you apply the accelerator.

I was the same with the E46 SMG hill start - tried it once, but never again. The M5 system is the same as the DCT M3 and works much better without any worry about damaging the clutch.

[clk55pete]

waremark said:

By the way, why are you considering a second car which is quite similar?

I don't have a hand for the handbrake - one hand is depressing the (foot) brake and the other is on the wheel. The hand control is a single lever "push-pull" so I push to brake and pull to accelerate.

The reason I'm considering an M3 is to track it. I track the AMG quite a lot but it’s very heavy. Plus I fancy trying something different but am quite constrained eg the car has to be big enough to take me my wheelchair etc.

I have looked at tiptronic Porsche's and they are still a consideration - although more costly.

[mat205125]

Noel said:

You can use the gear lever or paddles to change gear, I find a vary it, paddles when dead ahead or lever when on roundabouts etc.

Me too. Only did it one, but that was enough. Stayed in second approaching a T junction, and accelerated out of it and went to smoothly grab third gear whilst the wheel was at 180 degrees to the vertical .... What happened wasn't particularly smooth, lets put it that way

I think I'm understanding how the OPs hand controls are working, and think that with the "left hand pull" hill start function you might be ok. As another has said, you can feel the biting point with the accelerator, and balance the car on an incline with the clutch biting. Being fly by wire there is no reason to assume this wouldn't also be the case with a hand control as opposed to a accelerator.

[waremark]

Understand the choice of car, and that SMG may meet your purpose well. A pity DCT is still too expensive!

It might be significant which hand operates the brake. If it is the left hand, it might be difficult to activate the hill start feature.

I still think you need to find a car to be driven in, and have the features demo'd to you before you decide.

[clk55pete]

waremark said:

Understand the choice of car, and that SMG may meet your purpose well. A pity DCT is still too expensive!

It might be significant which hand operates the brake. If it is the left hand, it might be difficult to activate the hill start feature.

I still think you need to find a car to be driven in, and have the features demo'd to you before you decide.

It's my right hand that controls the wheel - so that appears okay. I've tried to show in the picture how the controls work. Push to brake, pull towards you to accelerate and steer with the steering ball.



I did sit in the passnager seat of a dealers while he drove it - this was in 2003 but he said he'd never driven an SMG before so wasn't much help in explaining all of its features, so yep I will definatly have a closer look.

What's the difference between the SMG II and the DCT for the driver (ie in terms of driving and controling the car)?

[waremark]

clk55pete said:

What's the difference between the SMG II and the DCT for the driver (ie in terms of driving and controling the car)?

The relevant difference which I was referring to is that in SMG II the hill start hold feature is activated with the left hand (pulling the paddle). In DCT it is activated with a firm push on the footbrake - so would not require you to release your brake lever in order to pull/hold the paddle.

For normal drivers this is a very minor part of the difference between the two. More significant differences are that DCT makes much faster, smoother changes. You get smooth upshifts without a throttle lift (in the SMG you get a big jerk unless you lift the throttle during upshifts as with a manual) and it is very satisfactory to drive like a regular automatic.

An interesting question for you is whether you could change down under braking, which you would probably want to do on track. I expect you could have your own equivalent of Heel and Toe, pushing your hand control to brake at the same time as pulling the gear paddle to change down??

[2skiddy]

Yes that`s a good idea about putting the gear switch on the brake/accel lever. Otherwise you can`t up or downshift as you need a third hand. The auto mode that was in my M3 CSL was not as good as the CLK 55 AMG.

[skeeterm5]

On my M5 if I hold the car on the brakes but in gear on a hill, when you let off the brakes the car holds itself stationery for about 5 seconds before it rolls back. Allows you time to move off the brake and onto the throttle smoothly.

Not sure if this is helpful or not as I dont know if the m3 is the same

S

[clk55pete]

Thanks chaps - I’ve found a guy who’s a wheelchair user and drives and M3 and so I will probably take the plunge and by a E36 M3 Evo and then set it up for the track....(takes deep breath).

The reason I am going for an E36 is because I can "fiddle" with it without feeling that I am destroying something that should be cherished.

Now I am off for some serious day dreaming: interior out; roll cage in; windows out; plastic in; brakes out; big brakes in; suspension out; coilovers in; exhaust off; Superspint on; wheels off; lightweight wheels on; brake houses off; braided hoses on; etc.

That should keep me busy over the winter.

Hey 2skiddy - done any track days lately?

I haven't but I do have a £100 vouncher for any trackday run by Motorsport Vision (so Brands Bedford; Oulton Park; Cadwell Park or Snetterton) that’s got to be used soon so should have some fun.

[2skiddy]

Hi Pete, Done 8 trackdays in the CLK 55. The removal of most of the interior made a huge difference! Car has just been sold as I need to move on to something else. I`m possibly looking at a Z3M coupe. A friend had an E36 M3 Evo SMG1 and the box get giving big problems. He sold it for spares/project eventually. Strip out the CLK, you know you want to!!!!! You should have bought mine ready to go.
Cheers

[clk55pete]

2skiddy said:

Hi Pete, Done 8 trackdays in the CLK 55. The removal of most of the interior made a huge difference! Car has just been sold as I need to move on to something else. I`m possibly looking at a Z3M coupe. A friend had an E36 M3 Evo SMG1 and the box get giving big problems. He sold it for spares/project eventually. Strip out the CLK, you know you want to!!!!! You should have bought mine ready to go.
Cheers

You've sold it already! I'm amazed at how fast people on here can get through cars! You are half right - I would like to fully track the CLK but I like it so much as my road car I can't give it up! I've looked at the CLK63 but it’s got less low down torque. That's why I've decided to buy and develop a dedicated track toy.
Lots of people have said stay away from early SMG gearboxes so I am also thinking about 1) buying an older Alpina B3 and using that as the base car or 2) buying an E46 330CI and using that. I want a car with similar acceleration and speed on track to the CLK and am trying to figure out if the 330CI stripped out and with minor changes to the intake and exhaust might be the answer.

All the best

Pete

[2skiddy]

Good luck Pete. It will be difficult to find a car with the grunt and excellent autobox to equal or better what you have. That is why I kept mine for as long as I did (19 months). I usually move on after 6 or less!