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OPEN diff vs LSD vs WELDED diff - VISUALLY + In depth EXPLAINED - Version 2

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This is version 2 of this video. The previous version was deleted as it had some misleading things in it. I also regret being a bit stubborn when defending the merits of my previous explanation, and although it did have some merit it was ultimately misleading and some parts were outright incorrect. I would like to thank all the commenters for pointing out the mistakes. Although some were rude and aggressive a great number of people was very constructive, mature and polite when pointing out the mistakes in the previous video, and to these people I offer my sincere gratitude. I don't shy away from admitting my mistakes, I see them as an opportunity for growth and work hard to correct them.
The mistakes in the previous video were: 1. Open diff sends more torque to slipping wheel. 2. Welded diff splits torque 50/50

So let's start with the open differential. This is something you can find in the vast majority of cars on the road today. Especially in nonperformance or „normal“ cars. The differential has one purpose. It allows you to take a corner. In other words a differential enables two wheels on the same axle to rotate at different speeds.
So what would happen if we didn't have a differential? Because the two wheels are now physically joined together they are unable to rotate at different speeds. Because of this the wheels have to make up for the difference in speed by skipping, hopping or sliding. You can experience this if you take a real car with a welded differential and try to negotiate it around a parking lot.
Of course this isn't a desirable scenario as it not only wears out your tires faster but it puts a lot of strain on your axles and other drivetrain components. On top of this it can make a lot of noise and draw unwanted attention. Obviously none of these issues will be present with a normal open differential.

To better understand the limited slip differential we have to go back to the open differential. If there's one thing you have to remember about the open differential is that torque being sent to the wheels through an open differential will always look for the path of least resistance. So if one wheel is easier to turn or slip that wheel will limit the amount of torque available to the other wheel. If one wheel is on ice and the other is on asphalt and it takes only 15 Nm to break traction on the ice wheel than the open differential will prevent the wheel on asphalt to receive more than 15 Nm as well. Now let's replace the open differential with our limited slip differential. As you can see the wheel with low traction doesn't spin at all and the vehicle takes of immediately. The answer to how the LSD achieves this is in the name itself. Limited slip differential. It limits wheel slip.

So in the same scenario with one wheel on ice the limited slip differential will not allow the slipping wheel to waste the torque potential of the engine. It will not allow the slipping wheel to prevent the wheel with traction from receiveing more torque. So if it takes 15 Nm to break traction on the ice wheel the other wheel will not be limited to 15Nm as well, instead the limited slip differential will bias torrque to that wheel and that wheel will receive more torque. A torque biasing differential can have a biasing ratio as high as 4:1. This means that if it takes 15Nm to break traction on the ice wheel the LSD can bias as much as 60Nm to the wheel on asphalt which is more than enough to get the vehicle moving quickly and without slipping.

The welded differential effectively turns the rear axle into a solid common axle and the entire rear axle behaves as a single unit, which means that the low friction on one wheel becomes irrelevant because 100% of the engine's torque is available to both wheels all of the time.

A special thank you to my patrons:
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Peter Della Flora
Daniel Morgan
William
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Pepe
Brian Durning
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Brian Alvarez
Holset90

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#d4a #LSD #weldeddiff

00:00​ Introish
02:43​ Getting unstuck
11:39 FF vs FR vs MR

posted by bloguarmkt