quattro diagonal test.

This shows how the EDS diffbrake system makes the car move out of this diagonal wheel spin. with only open differentials, one front and one rear wheel would spin, and even if the spinning front wheel got contact with the ground, so that both front wheels had traction, the car would NOT move without EDS, because the torsen center diff cannot transfer any torque if one of the axles loses traction completly, as if one rear wheel is off the ground like in this video, then that would be the only wheel that would spin, all others would stand still. So the EDS uses the brake to brake the spinning rear wheel so the other side that has all the weight also gets some torque and add a overall load to the rear axle, making the torsen transfer equal torque divided by the built-in Torque Bias Ratio (TBR) witch i guess is 1:3 on this car, so the front wheels gets the rear wheel torque divided by 3, witch makes the car move.

Category:

Autos & Vehicles

Tags:

• audi
• A6
• torsen
• quattro
• diffbrake
• traction
• test

[robinjohanssonmdh]

Hi. Nice car, with the best engine! I got a '95 C4 2,6 aut quattro and have done the same test, but I had to give it plenty of gas and use the brakes as diff-lockers. Is this normal? Also.. how do I disconnect the Electronic Stability Control?

[Swedediesel]

@robinjohanssonmdh well, if the EDS works as it should, you don't need ti give more gas than just above idle to activate the system, but the system will brake the spinning wheels, and to keep up the torque to the stationary wheels, you need additional throttle if the car stands uphill.

[robinjohanssonmdh]

@Swedediesel Såg nu att du var svensk! Jo jag stod i ganska brant lutning - med andra ord är quattro mer till för att ge fina köregenskaper än framkomlighet i komplex terräng=)

[Swedediesel]

@robinjohanssonmdh ja, men jag försöker hålla mig till engelska här, finns inget värre än när man hittar nåt intressant klipp och så är all text på nåt obegripligt språk.. t.ex. tyskar är makalösa på att vägra engelska.. och ja, om det lutar brant så orkar inte systemet att bromsa upp tillräckligt. då en hederlig mekanisk diffspärr som på äldre quattro hade inte skadat

[MGazT]

I thought the system was called EDL (Electronic Diff Lock) ? on the quattro models. complete with a torsen centre diff?

And the front wheel drives models had traction control?

[Swedediesel]

@MGazT yes, EDS is the german name, but translated to english, it will be EDL

i prefer to call it a diffBRAKE, as it is not a machanical lock, you get plenty of wheelspin to get the car moving, so that's more equal to an LSD

[robinjohanssonmdh]

@Swedediesel true

[Swedediesel]

@madisak yes that is correct, if you have the eds of course.

the mechanical difflock on older cars is a better solution because you don't need to spin the wheels too much, with EDS it is easier to get stuck, and you can't get 100% torque transfer to one side either.. but there are 2 reasons EDS outfeatured the difflock 1. lower production cost

2. nowadays even females are supposed to drive 4x4 cars ;)

[madisak]

So if i am stuck, and i have one wheel of the ground. Will you hear the ABS is working to transfer the torque? Like when you are breaking on ice?

Earlier i had an S4 but his car has a diff lock botton i could use :p

[Swedediesel]

Hi and thanks for watching!

yes the EDS is automatic and works in conjunction with the ABS brake system.

when one wheel spins, the ABS sensors detects that wheel spin and activate the ABS pump so that the brake applies on that wheel. there is no buttons in the car for the EDS, it works as long as the ABS works.