Help with Torque Steer

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#26

05-05-2009, 06:11 AM

Mach V Dan

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Quote:

Originally Posted by cmt52663

The rear bar helps it seems, and perhaps this is part of the reason why. With a stiffer rear bar, more weight transfer occurs on the rear axle and less on the front.

Sway bars have no effect on front/rear weight transfer. Since the sway bar pivots with the suspension, if both rear trailing arms are moving, the bar simply swivels along for the ride, and exerts no force on the suspension. The sway bar only acts on the suspension when ONE of the arms moves relative to the other -- during cornering, for example.

--Dan
Mach V

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#27

04-24-2011, 07:27 AM

basil49

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the Law of Unintended Consequences --

Quote:

Originally Posted by Ken G.

Torque steer is caused by an imbalance in the power applied to the ground between the two front wheels. If one wheel applies more power to the road than the other, the car will turn towards the wheel that's generating the least amount of power. This is similar to how a canoe is turned by paddling on one side and not the other, but in the car's case, the design of the suspension has a huge impact on how it's felt.

Anything that affects how the tire interacts with the road can cause torque steer, including the differential, wheel alignment, tire pressure, control arm adjustments, suspension geometry, and unequal drive shaft lengths caused by an off center front wheel drive transmission ...

Torque steer in front wheel drive cars has been a perennial engineering problem and there are no simple solutions.

Thanks, Ken, for helping me convince myself I'm not completely crazy ... but anyone ELSE is welcome to chime-in or rebut here --

My R56 MCS, even with Bridsgestone Potenza RE960s and a better rear sway bar for two years now, has always had a right-torque-steer issue on "agressive takeoffs" such as highway entrance-ramps ... which I learned to live with.

A week ago I got a REAL all-around-alignment from a REAL BMW technician, instead of the Bridgestone tire dealer treatment.

I'm driving a couple of days later, entering the interstate, punch it to get on, and thirty seconds after I'm in traffic I WAKE UP and realize HOLY CRAP WHERE DID THE TORQUE STEER GO? ... it was just GONE.

I'm an engineer, and very suspicious of the "placebo effect" -- so I'm pleased to be able to confess that I was NOT looking for THAT to happen. Subsequent tests give the same result.

SO: anybody else wanna pile-on here and tell me I'm imagining things?
Can a quality alignment-job added to quality tires correct torque-steer?

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#28

04-24-2011, 07:35 AM

zoltiz

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Quote:

Originally Posted by basil49

...
SO: anybody else wanna pile-on here and tell me I'm imagining things?
Can a quality alignment-job added to quality tires correct torque-steer?

On its own I don't think alignment can fix it, unless it's done by a magician, but MINI prides itself on having equal drive shaft lengths, so in this particular case doing alignment up to BMW specs could have easily fixed it.

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#29

04-24-2011, 08:55 AM

Laardilla21

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Just as a side note, I had my service tech give me the latest software update from MINI (Version 2.41, I think), which has the program which reduces torque steer. Amazing. I think it would normally cost an hour of labor to get done, but it is free to JCW owners. I am just good friends with my tech and got it for free.

There is a JCW thread on here about it that I will find and repost the link on this page.

Here is the thread:
https://www.northamericanmotoring.co...-retrofit.html

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