How Does Torque Steer Work?
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- čas přidán 2. 12. 2015
- Today, we are explaining torque steer, what it is, what causes it, and how to reduce it. There are a few problems I see with explanations of torque steer on the internet, so I'm going to debunk a few myths and explain what actually is behind this handling issue.
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I'm sorry about the lighting, and the "now"s, I'm not sorry about the high detail of the content though!
The differential angle makes far more sense from a Moment of Inertia perspective. I've driven higher powered FWD cars that had torque steer depending on the surface and the start angle of the wheels themselves. On a flat even surface like a dragstrip, it had zero torque steer.
This is a car with a torsional or helical style differential, so both wheels were getting even torque. This is a car that you guys never saw, the 9th gen US Civic Si.
doesnt that car have equal length driveshafts
So much better than the 30 second version!
Very informative, thanks for going into such great detail!
Very good video. Needed to watch it a few times to get my head around it, but explained very well
My Peugeot 306 (15 years) uses a solid axle to match the angles (Never really understood why, until now!) and I guess it have a very little Scrub Radius too (being very neutral in braking and acceleration)! I know it's a 110hp car, but I NEVER realized about any signal of torque steer.
After seeing your video about tyres and grip I understood the reason for the rear wheel steering system. I used to think "3 degrees? What difference will 3 degrees make?" but looking after slip angles, now I understand why it's a very well balanced car!
Shiit, I love my lion hahahaha
And your vids!
Thanks man!
👌 Thank you for the video. I needed that bit of info there....as I always felt like I was missing something.
Great video, some interesting points. I work for a Gm garage and in the UK we have a model called the astra they make a variant called the vxr that has enormous torque steer issues even with the equal length driveshafts as you mention. When they bought out the the latest model that's a completely different vehicle, they revised the diff that vastly eliminated a lot of this phenomena, but one thing I picked up on your video was the part about fords effort to eliminate with the knuckle. Is this a "floating knuckle" your referring to?, if so the astra vxr has also this arrangement , do you think this has more effect for reduction of torque steer rather than the diff alone. Thanks for the upload, I look forward to watching some more.
My car had a lot of torque steer. Someone told me to change the transmission mount. So I did it, and the torque steer was reduced to a big extent. However, it didn't completely disappear.
Should I change the engine mounts too???
most likely. for fwd cars they are all impacting each other. changing 1 and leaving 2 bad ones will brake 1st one.
+KYLE.DRIVES I found your channel last night and I've binge watched all your videos. Heck I've learned more here than the 5 years of Advanced Automotive Technology!
First video I have seen that seems to cover all causes of torque steer. I own a mazdaspeed3(MPS) and have thought of using a carbon fiber shaft for the long side. I guess I could use a normal shaft that is a bit thicker. Also many owners report that using a stiffer rear motor mount helps with the torque steer. Would using wider tires help control torque steer? Thanks for all the expertise!
Very good, well explained, thank you. Regards, Pete
Awesome video man.Keep it up.
Since I remap my 1.6 jtdm 120 HP AR Giu and when I put in dynamic mode, sometimes I feel torque steer and to be honest, I like to feel this 😂😂
Great video and greetings from 🇵🇹
Nice video. However, I have just had a problem with my Landcruiser, where I had to disconnect the rear prop shaft and drive it home as a 'FWD'. I have solid axles, front and rear. Still had noticeable steering torque.... How so?
My 2011 wrx sti is missing the rear diff bushing on the right side but it has them on the left, and I am experiencing significant torque steer to the right on acceleration. Could the flex of the rear differential cause torque steer like this? It is making me insane lol
Thank you. I learned something.
All of the mitigating factors you describe are implemented in the MK3 Focus ST. However, due to a small turbo and high torque at low rpm, torque steer is still present in our cars.
An important factor in torque steer is also the steering axis distance from the centre of the wheel, this should also be explained for viewers :). Keep up the good work
+motary That is also known as the scrub radius, which I make reference to several times during the video and explain here: czcams.com/video/As1_XGkrMfI/video.html
Thanks for watching!
great job
I'd imagine it has to do more with which side the engine is positioned since that wheel/tire would be getting more traction. You'll feel this under heavy braking (espically downhill) while hitting bumps in the road since all the weight is being shifted upfront and the front tires are getting about 80% of the traction under this scenerio. If you hit a bump with the side that has the engine on top it'll jerk more to that side as compared to the transmission side. Try it out for yourself. I honestly didn't finish this guys video bc he failed to mentioned that some cars have intermediate shafts.. so some fwd vehicles do have "equal angle" CV axles.. Also I'd imagine an LSD would eliminate the "cause" of torque steer as he suggested. My theory to truly eliminate torque steer in a fwd is positioning the battery over the top of the transmission and adding additional weight if needed to balance out the UNEVEN (Right:Left) upfront weight distribution.
Most FWD cars are econo-boxes with cheap open differentials, and torque steer is vastly more significant as power output increases. Take the Dodge Neon SRT for example, which is notorious for torque steer. A Limited Slip Differential virtually eliminates torque steer under heavy acceleration (which is the only time people actually care about torque steer) while doing nothing to change all the factors you've mentioned as causes for torque steer? Certainly, an open diff sending power to just one of the two wheels connected to the steering wheel has a far greater impact on torque steer under heavy acceleration than CV joint angles and whatnot. I'm interested to hear this explained as I really don't understand how an open diff can be ignored when the subject of torque steer comes up.
+John C Not true, in many cases a limited slip differential makes torque steer worse, for example cornering, which as I mentioned in the video around 6:25 . A frictionless, open differential will tend to provide equal torque to both wheels (50/50 split), thus reducing torque steer (while sacrificing ultimate tractive force) as there is less imbalance in the torques of the two wheels. Be careful about confusing wheel rotation rate with wheel torque. This is why an electronically managed differential (e-diff) is a superior option as it can strike a balance between torque steer and total thrust. If the Dodge Neon SRT has bad torque steer, I would hazard a guess that it is more due to poor geometry combined with a reasonable amount of power than its differential (if it is open diff)
In my experience (not textbook theory) a limited slip differential eliminated torque steer in straight line acceleration. I understand that torque steer can be linked to/blamed on all sorts of things, but when all other variables remained unchanged, i don't know how else you would explain it.
i always thought it was a result of powering wheels used for steering, never thought that an mr2 could suffer from the same thing
what part of Australia is your accent from?
Great video! Im still wondering though...I'm on my way into becoming a technician and during my time on the lube rack I came across a 2014 chevy cruze with tires on the driver side at 5/32" and the two passenger side at 4/32". Since the shaft on the driver side is shorter and producing more torque why exactly would the right side be wearing faster? The guy is real picky and im pretty sure everything is in alignment, it has around 60k on it though.
It has to do with wieght! The tire that has the engine positioned on top of it will wear out faster due to the additional weight being put on top of it.. That's the real cause of torque steer. Don't listen to this guy lol
Do you have a link to Ford's paper?
web.mscsoftware.com/support/library/conf/adams/euro/2002/papers/005_EUC_008_FORD.pdf
Really good explanation! I've always wondered how torque steer works. However, doesn't this mean that torque steer is reduced in an open diff, as both wheels provide equal amounts of forwards thrust?
+Antimation Studios Yes, an open diff will reduce torque steer over a limited slip diff , I kinda fumbled with the wording on that in the video a little bit, but I hope the point is still getting across!
my Honda prelude used to pull from left to right during wot. Even my 01 VW Jetta Wolfsburg had torque steer but not as bad as my Honda prelude.
FockYouMang did the talks there on your vehicles ever cause any negative problems
The point witht the CV joints is a bit hard to understand, especially since it seems to be one core cause of counter steering.
So the steering input from the CV Joints only happens if the gearbox is offset horizontally. Is my thinking correct?
Besides that a really good explanation!
Now I understand torque steer.
+Kalimerakis The point about CVs is twofold:
1. If you put torque through an angle using a CV, it will create an out of axis torque that will cause the steering knuckle to rotate. If the angles are different on the outboard CVs (eg. bumpsteer or ackerman), this will be felt as steering kickback.
2. If torque is put through an angle using a CV, the amount of torque output (the efficiency of the CV) will be related to CV angle. If your CV angles are uneven left-right, this will cause a difference in thrust force left-right, and create torque steer due to the scrub radius. This can be caused by several things:
-2.1. Unequal driveshaft lengths will result in unequal CV angles if the engine is moved fore or aft, or if the suspension is in equal bump or droop (i.e. accelerating)
-2.2. Differences in steering angle will change the CV angles left-right due to ackerman or bump steer
So to answer your question, you can get the steering input from the CV joints without the gearbox being horizontally offset, however it will be worse with the gearbox offset as per 2.1, Options 1 and 2.2 can both occur with symmetrical driveshafts.
Does that help?
+KYLE.DRIVES Helps a lot
Thank you!
are you explaining this under the assumption that this FF car is a 2 way LSD and not an open diff? Cause I thought the majority of torque steer comes from having an open diff causing the "1 wheelie pealie" effect because only one wheel under power
nice!
Why can't the engine be put in longitudinally like it was in the Dodge Intrepid?
My 60 hp Fiat Punto gets a half a second of torque steer, which is pretty weird for such a weak car.
Soo how do we go about fixing it? Hahah very well explained, but couldnt get my head around it.
Buy a car with rear wheel drive.
@Metalfan Rockfan It never snows where I live, so I couldn't give a rat's ass. Besides, I've driven plenty of RWDs in places where it snows in the winter, such as AK, IL, WA, ID, MT, CO. It's no big deal if you know how to drive.
do you have a version for dummies? dude, this was supposed to be clear and short...
Actually, I do: czcams.com/video/V4AUm_MAy2g/video.html
Also, nowhere did I say this video was meant to be clear and short, this is a comprehensive description of what causes torque steer, if you want clear and short I suggest you stick to the Kyle's Quick Explainers channel, not the full size KYLE.DRIVES videos.
iirc chevrolet solve this by making the longer shaft hollow to even out the inertia.
Vrry good Presentation ,I wish HONDA would Produce a AWD Civic -PreLIde
high rising terminal
What experiments and data do you have to back up your claims? Many new cars use the same drive shafts on both sides of the car and have another shaft connecting the furthest drive shaft to the diff horizontally. In this set up you have equal angles on both drive shafts but you still get torque steer. All cars want to turn either left or right due to suspension not being exactly perfect, that isn't torque steer. Torque steer is the snap you get putting down a lot of power that makes you change lanes and change back in a second. You are just guessing without knowing what you are talking about.
Moral to all this: avoid bying FWD
tl;dw = go buy a subaru
My last car was a 5spd Saturn Vue, horrible jerk to the right on heavy acceleration, hard starts....
Before that a 5spd SL1, same issue, not as bad though.... plymouth FWD before that, same issue.... just bought my first Subaru, and i find myself trying to correct for a torque moment on the steering wheel that isn't there....
I used to own a Mazda 3 MPS. Such a horrible thing to drive, reminds me of a wet dog running on a tile floor. Will never own a powerful front drive car again.
Dude looks stoned but talking straight
You cant match the fucking "stiffness" Of both shafts what are you even talking about? You can minimise torque steer by having 2 shafts of different lengths use different thickness but that is only at certain loads as twisting force isn't just governed by "Stiffness" as you call it. If you use more material in the longer shaft the twist up may be the same if you drop the clutch at 4000 revs but if you drop it at 6000 revs it will not be the same. You can only match drive shafts or differing lengths for certain loads, thus you CANNOT eliminate torque steer.
u have vast knowledge but everything you say is vocally not soo clear to me :(
It'll b great if u work on that
My starlet doesn't have any torque steer at all. Toyota must have much better engineers than Ford and Mazda.