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Why the E-diff

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Old 11-22-2017, 05:57 PM
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Default Why the E-diff

Why do you think Jaguar decided to go with an E-Differential as opposed to the normal posi-traction. It just seemed like a more complicated way of achieving a similar objective.
 
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Old 11-22-2017, 06:21 PM
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Progress and innovation, although sometimes it can backfire...


 

Last edited by JagRag; 11-22-2017 at 06:23 PM.
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Old 11-22-2017, 06:22 PM
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OR:


.... yeah, JagRag fixed his pick so I deleted my post of it.
 

Last edited by Cee Jay; 11-22-2017 at 10:27 PM.
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Old 11-22-2017, 06:30 PM
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Originally Posted by Cee Jay
OR:
Just like the electronic oil dipstick!
 
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Old 11-22-2017, 06:35 PM
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Per Wiki: "The Ford Motor Company lost $250 million on the Edsel's development, manufacturing, and marketing. The very name "Edsel" became a popular symbol for a commercial failure." "The company lost $350 million, or the equivalent of $2,900,000,000 in 2016 dollars, on the venture."
 

Last edited by JagRag; 11-22-2017 at 06:41 PM.
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Old 11-22-2017, 06:59 PM
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Originally Posted by JagRag
Just like the electronic oil dipstick!
or sealed for life transmissions.

Seriously though, here's the read on it:

https://en.wikipedia.org/wiki/Electronic_differential
 

Last edited by Sean W; 11-22-2017 at 10:11 PM.
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Old 11-22-2017, 10:30 PM
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Originally Posted by JagRag
Just like the electronic oil dipstick!
Yesterday, just for grins, I tried to shove a stranded bicycle brake cable down my oil suck-out-tube to see if I could find a level for Full Oil. It only went down about a foot and wouldn't insert further. No oil at that point.
Oh well, it was worth a shot.
 
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Old 11-23-2017, 06:53 AM
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Originally Posted by Cee Jay
Yesterday, just for grins, I tried to shove a stranded bicycle brake cable down my oil suck-out-tube to see if I could find a level for Full Oil. It only went down about a foot and wouldn't insert further. No oil at that point.
Oh well, it was worth a shot.
If you look at the maintenance manual at the exploded view of the parts you will see the oil tube has an S curve at the bottom so you can't get a wire down to the bottom. Also it is at the lowest point in the pan . The oil level sensor is located on the bottom of the oil pan.
Now back to the why an E-Diff instead of a normal posi
 
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Old 11-23-2017, 09:51 AM
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One problem with a fixed-lockup differential is understeer. A welded diff is the extreme case. In theory, an electronically variable lockup allows it to be optimized for improved handling and power transfer for different traction conditions under turning, braking, and acceleration. Have they succeeded? I don't know.
 
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Old 11-23-2017, 02:42 PM
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The E-diff solves a problem that nobody had. I could see it being useful on all-wheel drive but the benefit to cost/complexity ratio is way too low for RWD.

Jag was probably thinking about future maintenance and replacement revenue.

The most brilliant engineering is almost always the simplest. i.e. Torsen.
 
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Old 11-23-2017, 07:37 PM
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This might help explain why Jaguar used an e-diff. Taken from an EVO magazine article.

“There are also developments at the back end of the drivetrain where a new, more rigid subframe supports a brand new diff featuring what Jaguar calls Active Differential Control, a system that uses a clutch pack controlled by a small, fast-acting electric motor to control the proportion of torque sent to each wheel. In normal, undemanding driving the system allows the car to run with a regular, open diff to the benefit of noise, efficiency and – since mechanical limited slip diffs can promote understeer in some circumstances – handling. But when things get more tasty the diff control can shunt torque across the axle, promoting better stability, better response and ultimately acting like a slippy diff so that if you’ve got the stability control off you can indulge in what Jaguar politely calls ‘controllable power-on oversteer’. Given the passion and enthusiasm of the team behind it what they really mean is, ‘We’ve built a bloody great drift car”
 
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Old 11-24-2017, 06:57 AM
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Thanks mucf,

Sometimes with so many smart *** dudes trying to be cute it takes 10 posts to get a sane answer. Don't be offended boys, sometimes I'm pretty much of a smart *** my own self. I'll go get my coffee now.
 
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Old 11-24-2017, 10:24 AM
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Post #6 was good I thought.
 
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Old 11-25-2017, 10:40 AM
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Having the diff electronically controlled, along with the gearbox, ABS, damping, etc., gives you a lot of possibilities for intelligent manipulation of handling.
 

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