traction control query again

[mad4slalom]

really feel i want to experiment a bit with traction off, as i have read that people here say the m comes alive when you switch it off, and more and more i feel it sapping power when pushing it a bit, i used to love the z3mr just on the edge of traction,the tyres scrabbling for grip but never felt it was going to let go, only had a big rear unsettlement once when i backed off mid corner. i have seen videos of that lift off oversteer when it just steps out, but i thought that was the semi trailing arm set up uncambering, surely the z4 , 10 years newer should be a bit more controlable and less likely to bite you back. any scary moments in the z4m for any of you guys ?

 

[daz05]

Are you for real? Get out there and try it, just take it easy.

 

[ga41]

Find a big empty car park on a rainy day and go to town. Or perhaps do the more sensible thing and book an advanced driving course with a low grip surface driving experience.

I've had a few scary moment yes and i once banged the kerb while fooling around in the wet badly scraping my wheels and requiring a full refurb. I'm much more reserved now...

 

[Bing]

Or perhaps do the more sensible thing and book an advanced driving course with a low grip surface driving experience.

This is what I would do if I got an ///M. Sensible, but also practical - no point having the car unless you know how to drive it, right ?

 

[Stuart Truman]

Over on the (a word)register, they organise regular wet handling days at Rockingham. Maybe the forum should do the same. We've got a real mixed bag of levels of driving experience here and I know I'm still a little nervous in the wet in #69

I think it would be a hoot as well as good experience for some of us.

http://thealpinaregister.com/forums/viewtopic.php?t=13054

Edit - Cost is £125. Anyone up for this? I'm thinking about the one on the link. If I do it I could report back. Not sure if Ade or one of the other Roadster S owners who inhabit both sites have done one before...

 

[ga41]

If i was in the UK i'd join you guys if you'd organise something like that.

 

[Bing]

I've been on that wet grip course at Rockingham - scary, but fantastic fun and totally safe. The kick plate they have that rams the rear wheels in a random direction on entry to a ceramic skid pan is something else. I did it in a Kia something or other they had on site that was FWD... The Z would be so much more fun :evil:

 

[alfamale]

i would do the Andy Walsh car limmits day if i was going to do something, did it in the S2000 and came away with a much better feel for the car and a lot more respect for its handling, i still grin thinking about taking a sharp left turn at 70 mph steering with the tip of one finger, you learn throttle steering, slip angle, trailing brake its a fun day out and the only thing you hurt is the tyres and thats not that bad unless you want it to be.

 

[dalecan]

i would do the Andy Walsh car limmits day if i was going to do something, did it in the S2000 and came away with a much better feel for the car and a lot more respect for its handling, i still grin thinking about taking a sharp left turn at 70 mph steering with the tip of one finger, you learn throttle steering, slip angle, trailing brake its a fun day out and the only thing you hurt is the tyres and thats not that bad unless you want it to be.

That's a great day of driving. I took that 90deg left hand bend at 90mph in my old Z3 mc. When Andy came with me he got me to try it with one finger........yes one finger on the steering wheel. I learnt a lot that day. I need to find something like that in Seattle.

 

[mad4slalom]

went for a drive the other day and left traction off the whole time, not going to push it but you can certainly drive it sportingly , will gradually just "feel" the slip on a wet day as you suggested , slowly slowly tho as i really love the coupe the shape it is

 

[tombar]

i would rather learn to feel the slip in dry with tc on. try the limits and exits out of apex with back coming out slightly.. and then discover understeer correction with the throttle in 2 nd gear with tc still on.. its easy just go too fast in the corner and you will feel the understeer through your steering wheel... apply even more throttle instead of brake an car will sort itself out ... then when you will have rough idea how much throttle it takes, try it with tc off but dont get too confident , take very small steps

 

[mad4slalom]

tombar, best shot i've seen of ruby black, gorgeous. tried for a month with traction on and found it just dumps engine power , allowing zero slip, ever, so icant see how i can feel it gradually with tc on, so surely only way is tc off and gently , in the damp with space to play. :?

 

[tombar]

thanks mate... what i meant is to push it out of the corner near the limits of TC, personaly i can feel the back coming out a tiny bit before tc starts flashing... all it is just to get comfy doing that and then TC off, but dont let it step out too much because the car can really surprise nearly seen lot of ruby black all over the hard shoulder after owning the car for a week id love to get spare back wheels and tyres and kill them somewhere safe..

 

[mad4slalom]

ok; will give it a go, once ifigure out how to post pics will get som carbon black ones up. the coloured blacks are the most impressive i think.

 

[srhutch]

The ///M's traction control is mechanical in the LSD so cannot be switched off, you can only disable DSC.

 

[mad4slalom]

clarification required, when i say traction, i mean dsc, are you saying we still have some sort of driver aid when dsc is off ? because i read it thatthe m only has dsc and switch it off and you are on your own, also stated in the m supplement handbook. :?

 

[srhutch]

clarification required, when i say traction, i mean dsc, are you saying we still have some sort of driver aid when dsc is off ? because i read it thatthe m only has dsc and switch it off and you are on your own, also stated in the m supplement handbook. :?

In a way yes, we have the variable LSD which you could class as a driver aid, won't keep you out of a ditch though.

 

[Franzino]

clarification required, when i say traction, i mean dsc, are you saying we still have some sort of driver aid when dsc is off ? because i read it thatthe m only has dsc and switch it off and you are on your own, also stated in the m supplement handbook. :?

When you turn off the DSC (one step), then you are indeed on you own. Here some info about the Z4M DSC:

Dynamic Stability Control. This electronic traction and stability system, standard on all current BMWs, complements the M Variable Differential Lock.

DSC optimizes traction by electronic means, sensing wheel-speed differences and reducing engine torque and/or applying individual rear-wheel brakes. The crucial difference to the Z4 M Roadster driver between the M Variable Differential Lock and the DSC traction function is that the former in no way impedes power delivery, and is hence suitable for performance driving.

Yet in fact, even DSC’s traction function is calibrated to M-specific parameters. In combination with the fast-reacting engine, performance-oriented gearing and M Variable Differential Lock, its logic achieves the desired traction optimization in an M-compatible way…in other words, without undue interference with the differential lock’s ability to get power to the road.

The DSC stability-enhancing function is essentially unrelated to traction. Sensing differences in wheel speed in a critical cornering or avoidance maneuver, DSC detects any deviation from the normal cornering path (abnormal understeer or oversteer) and gently applies individual wheel brakes to help the driver keep the vehicle on the intended path.

As in other recently introduced BMW models, the Z4 M Roadster’s and Coupe's DSC system incorprates:

• Brake Drying. Acting on input from the windshield wipers’ rain sensor, the brake pads are periodically brought up to the rotors – just enough to eliminate any film of water between the pads and rotors, but not enough to cause any brake applications. This improves brake readiness in wet driving conditions.
• Start-off Assistant. Keeps the vehicle from rolling backward when stopped facing uphill. For 2 seconds after the brake pedal is released, the driver can then move off from rest without the car rolling back.
• Modulated ABS function. Thanks to new “analogized” control of the DSC brake valves, the anti-lockup function (ABS) is smoother than before. Instead of simply being fully applied and released, the application and release of these valves is now modulated.

Some DSC braking functions found in regular-production BMW models, such as Comfort Stop, are not included in the Z4 M Roadster because of its ultra-sporty driving character.