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King of Smart Gadgetry
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As most of you know that follow SCOA I recently installed the Daystar lift kit with new rims and the largest tires I could fit on the car (205/60 R15) without fender mods on my 2011 Fortwo.The traction control system on the Smart I'm sure is tweaked to operate under certain conditions and use whatever braking force is necessary to keep your vehicle under control when the system through the sensors deems that you are past the preset limits of G force. Well I'm sure they calibrated the system to operate with stock size tires. By having wider tires on the vehicle traction has greatly improved the handling and has really tightened up the steering response and it hugs the ground so well you can really lay into it and have it track a turn really well to a certain point. There are 2 different scenarios that I manage to unleash the traction control on a regular basis unless I hold back on the brake or the throttle. I drive a 4 lane interstate to reach the country road to my house.

Both sides of the interstate are separated by a median and at my road the west bound side is somewhat higher than the eastbound side. So at my turning lane I must turn left which is level, then it hits a slight grade acrossed the median and then you cross the other side of lanes which is banked to the outside as it is in a turn. If there is alot of oncoming traffic and I have to gun the car pretty hard to cross the lanes the uneven surfaces causes the traction control to kick in and it will in a split second lock up one of the front tires as I am attempting to cross traffic.

The other situation is on a 2 lane road that they followed a snake to build. The speed limit on the road is 35 mph. You veer to the right and climb up a hill. Then at the crest of the hill the road turns a sharp left and you start down the hill. A tap of my brakes to slow for the downhill part causes the traction control to kick in to lurch the to the right as I am making the left hand turn at speed.

With the larger tires and increased traction it really jars me and the car whenever the traction control kicks in. I was in a situation or two with the stock tires that traction control saved my butt big time and kept the car tracking true just as designed, but with increased traction on each wheel now it makes a over correction and senses the G force from it and corrects the other way. There is no way that I know of to adjust for this, so be aware when you add more wider rubber to the road the traction control is gonna behave differently than when you ran stock width tires. When it kicks in it scares the heck out of you and gets your attention. I have finally learned to not push it in these 2 situations and all is well. I feel the increased traction is superior 99.5% of the time, so the trade off is worth it. You may feel otherwise, but be aware it is going to react a little different and don't be surprised by it. DCO
 

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MY08 cabrio MY09 cabrio Brabus MY15 ED
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The 451 Traction Control is finely tuned to save you from yourself! Alter the stagger, wheel/tire diameter, grip, geometry, off camber turns etc and smart's TC may tie your sphincter muscle in a knot!
 

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I think what you're referring to is more likely to be the stability/handling control system rather than the traction control that should only manage the driven, rear wheels under acceleration. But you are right that the system does intervene significantly in situations when there is no loss of traction. Probably a couple of main reasons for that. One is that with the short wheelbase, it's easier for a fortwo to quickly rotate into an attitude where recovery is difficult or impossible so the stability control system is designed to intervene quickly. Second is that a fortwo just isn't a performance car with a stability control system designed to manage at-limit handling.

Like you, I've found the stability control to be excessively sensitive to situations where the car is unweighted and turning. Worse yet is unweighted, turning, then taking advantage of the extra cornering traction as the suspension compresses down on the tires. I've twice had the hazard lights come on in roughly that situation after the stability system has brought things to a halt.

I've found the most success driving it like a momentum car by taking slightly earlier apexes, sacrificing corner entry speed for a bit more mid-corner speed. As long as all of the turning is done smoothly and speed changes when cornering are minimized, the stability system seems to stay asleep enough for some pretty significant fun.
 
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