Torque Steer - What can cause it?
Thread Starter
Donating Maxima.org Member
Joined: Apr 2003
Posts: 405
Torque Steer - What can cause it?
I know this has been covered plenty, but one quick question:
Can rear worn/blown shocks contribute greatly to torque steer? Maybe someone can point out something I've missed.
I got new rear KYB gr-2 shocks sitting around, because my old rear shocks are worn (they bounce once doing the test). I have all the nissan bushings ready too.
I also recently installed an otto racing (ebay, $28), FSTB, but the torque steer is still there.
I also did a front alignment 1 week ago, since I changed out all the front bushings and bearings for my struts (a lil noisy, and the dreaded creak). She runs straight, except when i gas it.
I still need to still re-inspect all my polyurethane front bushings...maybe check on control arm "tie-rod" ends (I forget what they're called). Basically see if I have any play on the wheel, but I think I checked 'em when I did all my front strut bushing/rubber/bearing replacement.
What else could be causing torque steer? Old bushings on the steering rack? Old tires (have 1/2 thread of new). Or like my first question, worn rear shocks?
Would wider new tires eliminate this? I swear I haven't noticed torque steer until 3 months ago.
Can rear worn/blown shocks contribute greatly to torque steer? Maybe someone can point out something I've missed.
I got new rear KYB gr-2 shocks sitting around, because my old rear shocks are worn (they bounce once doing the test). I have all the nissan bushings ready too.
I also recently installed an otto racing (ebay, $28), FSTB, but the torque steer is still there.
I also did a front alignment 1 week ago, since I changed out all the front bushings and bearings for my struts (a lil noisy, and the dreaded creak). She runs straight, except when i gas it.
I still need to still re-inspect all my polyurethane front bushings...maybe check on control arm "tie-rod" ends (I forget what they're called). Basically see if I have any play on the wheel, but I think I checked 'em when I did all my front strut bushing/rubber/bearing replacement.
What else could be causing torque steer? Old bushings on the steering rack? Old tires (have 1/2 thread of new). Or like my first question, worn rear shocks?
Would wider new tires eliminate this? I swear I haven't noticed torque steer until 3 months ago.
cause each wheel is spinning at its own speed... and when you accelerate hard each front wheel is pulling as hard as it can but the power is not distributed equally. plus on axle is longer than the other contributing to this. Thats why LSD is a good thing to have , it helps the wheels spin together which is good when making more power.
None of you guys are quite on the right track as to what causes torque steer. Read this and educate yourselves: http://www.sportcompactcarweb.com/ed..._technobabble/
When you turn the steering wheel, it turns about an axis that is, surprisingly enough, called the steering axis. (I told you this was simple.) As with anything that turns about an axis, if you push on it, it will probably turn. The simplest example is a door; it rotates about hinge, and if you push on it, it will rotate.
So what's pushing on the wheel? You and your right foot, actually. The engine's torque output moves the car by pushing on it right at the contact patch between the tire and the ground. When the tire is sitting flat on the ground, that contact patch is basically a rectangle, and you can assume that all the force is being applied right in the middle of it. Now, the Dave Point (remember, this is the point where the steering axis hits the ground) is the point that the contact patch rotates about, so if the Dave Point is also in the middle of the contact patch, the car can simply accelerate in a straight line. If you try to open a door by pushing on the hinge pin, you won't go anywhere. Similarly, if the Dave Point is right in the middle of the tire, the car should accelerate in a straight line.
Of course, as you have probably guessed, it is very difficult to put the Dave Point in the middle of the tire. The steering axis, on cars with MacPherson strut front suspensions (like Nissan Sentras, Subaru Imprezas, and just about anything cheap), is defined by the line that connects the top of the strut and the lower ball joint. Since the strut can't pass through the middle of the tire, and the ball joint has to battle with the brake rotor for real estate, it is quite difficult to get the Dave Point into the middle of the tire. Other suspensions define the steering axis different ways, but virtually all of them present some sort of challenge to proper Dave Point placement.
In most cases, the Dave Point is slightly inboard and slightly in front of the center of the contact patch. The distance between these two points is called the scrub radius because it defines how far the contact patch has to be scrubbed across the pavement when the steering wheel is turned. Now, if you push on the tire at middle of the contact patch, and the Dave Point is off to the side somewhere, the tire will try to steer around the Dave Point. The higher the scrub radius, the more steering torque will be generated, and the more pissed off you will be.
So what's pushing on the wheel? You and your right foot, actually. The engine's torque output moves the car by pushing on it right at the contact patch between the tire and the ground. When the tire is sitting flat on the ground, that contact patch is basically a rectangle, and you can assume that all the force is being applied right in the middle of it. Now, the Dave Point (remember, this is the point where the steering axis hits the ground) is the point that the contact patch rotates about, so if the Dave Point is also in the middle of the contact patch, the car can simply accelerate in a straight line. If you try to open a door by pushing on the hinge pin, you won't go anywhere. Similarly, if the Dave Point is right in the middle of the tire, the car should accelerate in a straight line.
Of course, as you have probably guessed, it is very difficult to put the Dave Point in the middle of the tire. The steering axis, on cars with MacPherson strut front suspensions (like Nissan Sentras, Subaru Imprezas, and just about anything cheap), is defined by the line that connects the top of the strut and the lower ball joint. Since the strut can't pass through the middle of the tire, and the ball joint has to battle with the brake rotor for real estate, it is quite difficult to get the Dave Point into the middle of the tire. Other suspensions define the steering axis different ways, but virtually all of them present some sort of challenge to proper Dave Point placement.
In most cases, the Dave Point is slightly inboard and slightly in front of the center of the contact patch. The distance between these two points is called the scrub radius because it defines how far the contact patch has to be scrubbed across the pavement when the steering wheel is turned. Now, if you push on the tire at middle of the contact patch, and the Dave Point is off to the side somewhere, the tire will try to steer around the Dave Point. The higher the scrub radius, the more steering torque will be generated, and the more pissed off you will be.
Thread Starter
Donating Maxima.org Member
Joined: Apr 2003
Posts: 405
I read this before (mzmtg's reference link). This is definitely good info.
And to mention, I had questioned whether wider new tires would help torque steer but...
I guess my other question is: would a stiffer rear-end help out, since the rear-end lowers down/front-end lifts up easily during hard acceleration (with bad rear-shocks). I have more of a snapping back motion, when I let off the gas.
I guess I'm understanding this article somewhat, but wonder if this (bad rear-suspension) effects it (torque steer).
edit: Or maybe, I'm thinking now, a bad rear-suspension exacerbates the effects of torque steer (snapping back when letting go of the gas). I mean, yeah a steering wheel will turn on it's own with torque steer, but it shouldn't feel like it's snapping back when letting go of the gas. Is this right?
And to mention, I had questioned whether wider new tires would help torque steer but...
I guess my other question is: would a stiffer rear-end help out, since the rear-end lowers down/front-end lifts up easily during hard acceleration (with bad rear-shocks). I have more of a snapping back motion, when I let off the gas.
I guess I'm understanding this article somewhat, but wonder if this (bad rear-suspension) effects it (torque steer).
edit: Or maybe, I'm thinking now, a bad rear-suspension exacerbates the effects of torque steer (snapping back when letting go of the gas). I mean, yeah a steering wheel will turn on it's own with torque steer, but it shouldn't feel like it's snapping back when letting go of the gas. Is this right?
Wider tires will make torque steer worse, usually.
Also, exagerated weight transfer from worn rear suspension could make it worse as well.
But, the main culprit is the geometry of the front suspension itself. That can't really be changed.
Also, exagerated weight transfer from worn rear suspension could make it worse as well.
But, the main culprit is the geometry of the front suspension itself. That can't really be changed.
Well, I have read that too. Good explanaition. I guess I dont know how best to say it. I do have 8" wide tires and also get some retarded amounts of torque steer. When the road is uneven it is worse. You get used to it and counter act it like second nature after awhile. I would say 1st and 2nd gear is usually the time it kicks in most because 1st 2nd gear is the gear I most let her rip in. At least since I moved to the Atl . blah blah 
Thread Starter
Donating Maxima.org Member
Joined: Apr 2003
Posts: 405
heh, after all that stuff...i rechecked my control arm bushings, and the passenger side control-arm bushings were completely gone. I had a 1/4" play in the control arm.
I never did replace the passenger control arm bushings (don't ask why heh, I did the driver side b4 tho), but I did replace them last weekend with the energy suspension ones (suspension.com).
Torque steer is gone. I mean, I can barely notice it.
Road vibrations are really apparent now tho! :P
Anyway, re-check all front end bushings if you have dramatic torque steer.
PS. EDIT. CLARIFICATION: DRAMATIC Torque steer, with a stock car.
I never did replace the passenger control arm bushings (don't ask why heh, I did the driver side b4 tho), but I did replace them last weekend with the energy suspension ones (suspension.com).
Torque steer is gone. I mean, I can barely notice it.
Road vibrations are really apparent now tho! :P
Anyway, re-check all front end bushings if you have dramatic torque steer.
PS. EDIT. CLARIFICATION: DRAMATIC Torque steer, with a stock car.
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