Hi all,

I've got a 2007 S with LSD and 17in run flats and too much torque steer. Always had it. What are my options? Convert to regular tires? Go to 16in wheels? Is the LSD helping or making it worse? Dealer said the car has zip wrong with it, but it drives my wife nuts. Would a special wheel alignment help? You see it with any brisk acceleration.

Thanks!

 

I have the same issue with my 09 LSD S. I've heard of at least one example where the JCW tuning kit significantly reduced torque steer. Maybe that's a route to take if more reliable testimonials can be found?

 

I'd heard the LSD make torque steer worse as well, I believe I'd read that swapping to non-runflats can reduce it a bit.

Anyone out there had the chance to compare a MCS with/without LSD to compare how much it affects torque steer?

 

Does it pull to the same side every time? And how hard is your wife pushing the car to notice the torque steer? I redline mine with overboost in 2nd (EDLC/no LSD/17" runflats) and there is no torque steer to speak of. Even with DTC off.

 

Mine alternates sides, more severe in lower gears.

 

I switched to non-runflats. I have both 17x7 wheels stock size tires (205/45-17), and a set of 16x7 wheels with 205/55-16 tires. My 2007 MCS has LSD. Torque steer is still strong.

With LSD, torque steer tends to switch from side-to-side. When one wheel begins to spin, LSD transfers power to the other wheel, that can cause it to start to spin, transfering power back...and so on.

The only thing I've heard that is supposed to reduce it is increasing grip of the front tires. You could try going for a wider tread, or just switch to a really sticky tire. The new Dunlop Direzza Sport Z1 Star Spec (make sure it is the Star Spec and not just the older Z1) is supposed to be very sticky, but wears fast.

 

I thought I had pretty bad torque steer, but I rotated the tires and now I hardly notice it.

 

Thanks for the comments. We both experience TS. It occurs way below redline. Searching the forums it also sounds like the control arm bushings in front are part of the problem, but boy! What a pain to swap those out.

I may just swap to regular all season tires.

It pulls to both sides, which some say is due to the LSD. When we tested a car it was a non-LSD MCS without the sport package. It did not pull as much as our car.

J

 

LSD makes it worse. But lowering the car seems to make it better!

--Dan
Mach V

 

The front control arm bushings make a HUGE difference! Also, lowering the car makes a big difference. I went from H&R Springs to Cross Coilovers and lowered the car even more. Now I don't notice the torque steer hardly at all.

 

does this make sense?

i have a lowered jcw, with a quaife and don't notice torque steer much

on the other hand i usually have a pretty firm grip, so perhaps i'm accustomed

i think torque steer happens when two points are not the same

one point is where vertical axis of rotation of the wheel hub meets the pavement

the other is the constantly shifting (slightly) center of the contact patch itself

if the contact patch on the left front is centered an inch outside that center of rotation, then the hub is torqued clockwise (right turn) under acceleration and the opposite during braking

assuming a symmetrical setup, such an offset would turn the car right on acceleration if the rf tire lost traction, and left if the lf slipped

if this is true, then two things come to mind regarding torque steer

1. the wheel offset would be one way to affect the mis-alignment (or narrow the gap between patch center and rotation axis)
2. raising or lowering the car, if it affects the angle of the hub axis (which i think it does), would also increase or narrow that gap
3. finally, rake and camber would affect that axis - however adjusted, right?

damned if i know for sure - anyone have the expertise to set this straight?

 

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. Damage caused by hitting curbs can change these things enough to cause torque steer, I know that from experience.

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

 

Torque steer drove me crazy as well. 3 weeks ago I installed the H&R springs and let me tell you what a huuuuuuge difference it made!
Very pleased with the results!

 

Did you do it yourself? How much lowered is the car?

I tried lowering the PSI to 36 and that actually is an improvement. Less harsh a ride, too. It doesn't solve accelerating on uneven surfaces, but I wouldn't expect it.

J

 

Yeah, I installed the springs with a buddy of mine and it took about 3 hrs. Not that hard to do. It lowered the car just under an inch an a half. There are springs out there for the R56 that do not have as much of a drop as those.

 

you're gonna have torque steer in a high torque front wheel drive car.

lowering the car DOES help quite a bit.

 

Still curious on root cause...

From http://wikicars.org/en/FWD --
:Torque steer can be a problem on front wheel drive cars with higher torque engines ( > 210 N·m ) and transverse layout. This is the name given to the tendency for some front wheel drive cars to pull to the left or right under hard acceleration. It is a result of the offset between the point about which the wheel steers (which falls at a point which is aligned with the points at which the wheel is connected to the steering mechanisms) and the centroid of its contact patch. The tractive force acts through the centroid of the contact patch, and the offset of the steering point means that a turning moment about the axis of steering is generated. In an ideal situation, the left and right wheels would generate equal and opposite moments, cancelling each other out, however in reality this is less likely to happen. Torque steer is often incorrectly attributed to differing rates of twist along the lengths of unequal front drive shafts. However, Center-point steering geometry can be incorporated in the design to avoid torque steer. This is how the powerful Citroen SM front-wheel drive car avoided the problem.:

The image (hperlink at bottom) depicts the "scrub radius", or the offset between the vertical axis of rotation and the contact patch center... This illustration is from a rather high tech approach to taming the Focus for competition applications.

Another reference I found helpful on this question is Fred Puhn's book "How to make your car handle" [http://books.google.com/books?id=cr4IyD5l1NQC] on page 24:

"When the driving wheels also steer, as in the case of front-wheel drive cars, the designer has to be very careful with drive line design and front suspension and steering geometry to minimize torque steer. To do this the steering-pivot axis is designed so that it intersects the exact center of the tire contact patch, or as close to it as possible."

I believe that a Mini that has been lowered significantly acquires a slight increase in negative camber on the front axle, which has the side effect of shifting the contact patch slightly inwards from the true centerline of the tire. This shift has the effect of narrowing the offset between the steering-pivot axis and the contact patch center and therefore reduces torque steer somewhat.

I'd respectfully suggest that the easiest factor that those of us on the aftermarket side of this issue can do to affect this geometry is to be careful with the wheel offset. When we go to wider rubber (and wider wheels to mount that rubber) I suspect many of us use insufficient wheel offset and aggrevate the problem. In my case the offset that is possible is determined by the clearance between the coil-over springs and the tire sidewall, so an ideal choice from the standpoint of managing torque steer may not actually fit.

Cheers,

Charlie

https://www.northamericanmotoring.co...hp/photo/84526

 

My car feels entirely different since I had the H&R springs and larger rear sway bar installed. I do not even feel the torque steer now! I would highly recommend it. I feel now that the car is stiffer it helps?

While getting my car serviced the other day, I drove a similar R56 with the same options and what a difference. I had totally forgot

J

 

Whats the problem????
All you need to do is know how to driver compensate driving a front wheel drive car. Rear wheel drive cars also have a lot of different handling flaws that need to be learned by the driver such as oversteer or understeer etc. Even some all wheel drive cars have high speed turning problems such as plowing that needs to be learned and compensated for.
Wants you get used to what is happening it is just not a problem anymore.
Just floor it and hang on to the steering wheel.
After you get used to the torque steer you will find it is no problem at all in how the car handles.
Ronnie948

 

I have an 08 Clubman S with LSD. Under full throttle the torque steer is pronounced, entertaining (for me), and engaging. I hold on and pay attention. If I drive like my dear departed grandmother I have no torque steer and my passenger is assured of dry pants.

 

aside from being fascinated with the engineering, I'm with you folks as a driver.

When I'm using a lot of throttle I have both hands on the wheel and am pointing the car carefully. My car can break traction under acceleration with both wheels (the Quaife) in many situations in the lowest two gears. In autocross of course I'm aiming to be at that point as often as possible.

A friend once took his first drive in my VW GTI (one of the originals, back in the eighties). He was pulling out from a parking lot into 40 mph traffic on a fairly wide seconday highway. He turned the wheel right, eased the clutch out and then opened the throttle as the car started to move. In the next 20 feet he got a lesson in torque steer as the RF broke traction under strong acceleration (the GTI was pretty quick and wearing wide rubber) and the steering wheel jumped clockwise. I think he almost lost his grip, as he was one-handed on the wheel with the other on the gear shift.

He said "oops!" I remember, as he straightened the car out.

 

one more thought...

Aside from wheel offset to reduce the steering axis to patch center distance, controlling weight transfer (reducing it at the front axle) would seem to help too. This would work because if the amount of traction (which is weight dependant) at the front end is balanced, then the opposing torques from each front wheel would also be balanced - so no net effect back to the steering wheel.

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.

It also helps with the understeer of course, which is why I use one. It hadn't occurred to me that the seconday benefit might be a reduction in torque steer, but it seems to figure - given what Fred and others are saying about the root cause of this condition.

 

Is the torque steer severe enough that anyone regretting getting the LSD?

Still in the planning/saving stages and threads like this are very usefull in making option choices.

I've owned rear-wheel sports cars and always get the LSD if offered, this would be my first FWD sporty car.

 

The R56 cars have a lot more TORQUE, so they exhibit much more torque steer than your R53 car.

--Dan
Mach V

 

BTW, my wife is happy enough with the tires at 36PSI...so that may be enough for now (though I was looking forward to a project...).