Torque Vectoring Differential – Explained



How does torque vectoring work? What is a torque vectoring differential? A torque vectoring differential acts very similarly to an open differential, except the axle shafts have planetary gearsets and clutch packs which allow them to lock up with the differential housing, thus altering the amount of torque sent to each wheel through different gearing in the planetary gears. As much as 100% of the available torque can be sent to an individual wheel with some setups, depending on circumstances and the differential used. The differential in this video is directly from a Lexus RCF.

NOTE: The end of the video is misleading. It doesn’t incorporate how the planetary gears are used to alter the torque, and just states that they are locked with the differential housing. While it is true that the torque does transfer from the differential housing to the planetary gears, it is not explicitly shown in the video how this works. Here is a link describing this further (image C). http://www.fsb.unizg.hr/acg/activ_diff_research.html

Related Videos:
Torsen LSD – http://youtu.be/wiq1Rk5wqds
Viscous LSD – http://youtu.be/w2bRb17jJ1U
Clutch Type LSD – http://youtu.be/ujsxq9WBllU
Differentials: http://youtu.be/Hv0jYDWp0ZA
Open vs. Locked Diff: http://youtu.be/gwJEU7p9U2Q
Open vs. Locked Diff Part 2: http://youtu.be/_HOa0aRZYpw
Multi-plate Clutch: http://youtu.be/SQvFg4WbdZ4

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45 thoughts on “Torque Vectoring Differential – Explained

  1. i swear this guy just reads wikipedia and tells us what he read

  2. What is the difference between a torque vectoring differential and an Limited Slip Differential?

  3. Ethel Berry says:

    Why is this now showing on my dashboard instead of my mileage? I just had my rear brakes done!

  4. Dynamics question: Cheap brake-based torque vectoring is inferior because it sacrifices engine power as heat into the brakes, among other things (also heats/wear brakes more quickly).

    These clutch packs generate heat also when they are not fully engaged. Where does that heat come from? Does this heat mean that engine power is being wasted?

  5. Joe Goodman says:

    Does the 2018 Honda Accord have any type of torque vectoring?

  6. dilsher12 says:

    Sorry but this is a very misleading video in the way does it explain how torque vectoring works . I am no engineer I was actually looking for a something that explained how torque can be varied going to each wheel . This video does no help in understanding it at all . Reading the comments its actually confused people even more

  7. alekivk says:

    I still don't understand how the planetary gears work in this. Is the output another sun gear? Is the ring gear fixed to the housing? If the clutch is engaged on one side, what is being locked together? Does it lock the planet carrier to the housing?

  8. Scott Levine says:

    I was wondering if you know about the lifespan of the clutch packs. It seems with systems like these that the clutches would get used often and heavily and would cause wear quickly.

  9. John Moore says:

    At 4:44 what does the diagram mean by negative torque is applied. What is negative torque and how is it applied.

  10. How is this different from an LSD ? What if I could use a Torsen differential/LSD which could be activated during cornering as well (and not just during the case of unequal grip) ? Won't that essentially act as an equivalent Torque Vectoring Differential?

  11. Making project at my university (FSB) about differentals, with help of your vids. Opened description and saw link from my university … funny stuff

  12. I'm used to seeing the planetary gears in a auto transmission., I though the video was well presented.

  13. Conrad Hofer says:

    What is the AWD system consist of in 2004 Olsdmobile Silhuette mini van?

  14. ZKaiLe says:

    because when the clutch lock up it act as a solid unit with the differential housing, it's exatly the same result as braking. So why not building only brake torque vectoring system? You could save some weight, of course brakes'd heat up faster..

  15. MostlyClaudy says:

    How does the Torque Vectoring Differencial compares to the Torsen LSD? Is the Torsen LSD solution more effective sending torque to the wheel with higher grip?

  16. Thank you for that explanation. Right after the diagram of how it worked through a turn, I then understood the mechanics of it, but then again my mind is a bit weird that way. Regardless; a very good explanation!

  17. djaytco says:

    how much more the brakes wear out with audi's quattro torque vectoring system? 10%? 35% more?
    they use the breaking system to make the vectoring work…

  18. MrPl0xygen says:

    Does torque vectoring help in tight turns ?

  19. Torque vectoring differentials is a win win win deal!

  20. Question: what kind of center differential uses the 2017 Ford Focus RS ????

  21. is this the one fiesta St has??

  22. Cory Engel says:

    The link is dead that you posted in the description that explains how the planetary gears overdrive the outer wheel when the clutch pack partially engages – could you please do a short video elaborating?

  23. junoguten says:

    Will this allow you to have an even smaller turn radius in a RWD without the front wheels just sliding forward? How much smaller do you think?

    Alternatively, in a RWD, would having an open differential but having brakes that can apply to one rear wheel or the other when at very low speeds with the steering wheel is turned very far help you with that?

    Also, I have a general feel for when the front wheels will just slide instead of actually turn (from my sit-on lawn mower. It's RWD, open differential and can turn the front wheels really far. Measured about 65 degrees on the outer wheel on max turn).

    It seems to not want to turn anymore at different angles depending on the inclination of the ground, the direction I lean on it, and the surface it's on. Maybe there are other factors I don't know about too. What I have no idea how to do is calculate what angle it's gonna be.

    Anyway I had this idea because I discovered that short of spinning one wheel, leaning over the outer rear tire seemed to mean I could turn the steering wheel slightly more and still turn.

    Just figured if that could somehow be used to lessen the eternal pain of doing U-turns with your city car on tight roads, that'd be swell.

  24. Why do cars need torque vectoring differential when they can just brake the inside wheel? Mercedes uses it, and torque vectoring by braking are cheaper, less complicated and lighter than torque vectoring differential.

    Or am I missing something here?

  25. Adam Osborne says:

    Thanks man! That was a really great explainer, even for a luddite like me!

  26. Did Haldex Design this?

  27. Transfer more torque to the inside tire? (on stage 2, the end of the video) Looks like it's breaking… the is going backwards… Than stage 4 is going forward.. and to more torque to the outside tire..

  28. A newbie here. Don't rlly get stage 2 of the cornering. When turning, the outside wheel has higher velocity plus there's slightly more body roll(weight) to the left so shouldn't more torque be provided to the left wheels. Plus intuitively if u want to rotate clockwise u want more torque on the left than right, going forward

  29. Trang Tran says:

    Great explanation of the basics of how it works. I've watched your other videos especially on differentials so I can see the differences between this type and the other types

  30. FHI says:

    I still prefer the VLSD, simply because it's less complicated and solid

  31. Martini time says:

    Man… The good old days when you just had an LSD diff that's really good for fun and good old ABS to help you when your too distracted to help yourself out a sticky braking situation…. And that's is if your car was new enough with ABS if not you better be on point with your braking skills all the time, snow or raining… Or sand…. Or a muddy hill.

  32. Kevin Kuusik says:

    Do you know when was first time Torque vectoring was used? F1 for example. WRC cars used this kind of electric differentials in beginning of 2000 I thing, now it is forbidden.

  33. So I've just watched all of this series in the past 24 hours. Would I be correct in saying modern formula one cars run torque vectoring diffs like these (a very loose, like)? After the viscous episode I thought they might use those with an ER fluid for the driver controls. Is it more possible that they do use viscous diffs with the only reasoning being that the mid corner control is usually labelled "viscous"? The only other thing I can think of is they use a "torque vector" setup like this with ER fluid instead of cams and step motors. Thoughts?

  34. HTBLuVA says:

    so, is it possible to LOCK such a diff(both clutchpacks fully engaged)?

  35. mikef058 says:

    In reference to the Evolution X and the 2015 WRX and STI, how do those torque vectoring systems differ. It seems like the Evo X uses a system like what was explained in the video. However, the WRX and STI uses a "brake assisted" system Subaru calls "active torque vectoring".

  36. xXhunter47Xx says:

    It's actually amazingly simple how this works when you explain it! I'm also interested in how the computer reads and sends data, although that may be a lot more difficult to do so.

  37. shboo na says:

    hmmm in simple terms electrical Differential with LSD but not mechanical parts just before there were manual transmission now there is automatic transmission

  38. AndrovT says:

    What would happen if the open differential would be replaced with a LSD?

  39. Timur Hafouz says:

    Hi Jason. Would the torque vectoring lsd diff be better than the torsen and viscous lsd diffs for regular and performance driving ? Whats your opinion ?

  40. aNiederbayer says:

    i really don't get it… in your description link it's figure (c) thats most common to this kind of torque vectoring differentials i guess? In the draft i get it, there are two different size sun gears and two different size planet gears, the planet gears are directly connected. When the clutch pack is open, it does not influence the torque distribution. When one is closed, the planet gear carrier is braked down and the torque comes from the differential housing, to the inner sun gear, to the planet gears, to the faster spinning outer sun gear and finally to the wheel. But in your video the planet gears look totally the same size? how does this work? there's a video animation on youtube of the "ZF vector differential" and there it looks the same, the planet gears are not only the same size, they are one gear! This thing is really complicated…

  41. You forgot to mention role of planetary gearsets. If clutches would simply connect output shafts with diff-housing it would work like simple LSD with added control of how much it can slip.

    Planetary gear sets allow to direct power to one wheel instead of locking whole differential.
    Principle is similar like modern tanks steering systems with two power inputs.

  42. Ajae Clacken says:

    amazingly plain explanation really helped

  43. Pogaspm says:

    Since the clutch packs will be constantly engaging, disengaging and operating half engaged, will there not be a high rate of wear on them?

  44. Over engineered crap that adds cost, weight and complexity. A standard limited slip differential is a better trade-off for performance vehicles and then locking diffs for off-road. If it's something like family SUV even just braking the spinning wheel works for getting up that slippery hill.

  45. jdmeaux says:

    More electrics to cause more problems.

Comments are closed.