Four wheel drive Ratio?

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whats the ratio for rear vs front power provided on S3?????
is it 50-50???
or is it more towards the front like 40-60 ????
 
They are two wheel drive until the fronts start to slip and then it instantaniously tansmits power to the rears as is required to eliminate any wheel spin.

 
Wow. If I drive up from Bristol to London and back on the motorway with some fun along the way, I can average 33mpg or once even 35mpg.
 
In previous posts it was suggested that pulling the Haldex fuse made the car FWD - pulling the Handbrake up a notch also had the same effect.


Greg
 
I think the maximum split is 50:50... This is because the rear wheels are the only ones that are disengaged. if it were to splot 99:1/1:99, it would need to be able to cut power to the front wheels too, which it cant.

Rich
 
I suppose the easiest way to find out is pull it up a notch and see it spins when you floor it
 
Rich is correct in that only the rears can disengage, the fronts will always have drive. As mentioned earlier, the S3 is pimarily FWD up until the point that the wheels slip, then the Haldex engages to transfer power/drive to the rear wheels, until all wheels are going at the same speed. The question is drive ratio split between front and rear, which in this case is 50:50 F/R under most extreme conditions.

[ QUOTE ]

1. There are situations where near 100% torque transfer to the rear axle
occur. An example is if the front wheels are on ice and the rear wheels are
on tarmac. In that case the front wheels have (almost) no grip. In that
case, the Haldex coupling will transfer all torque to the rear axle and
prevent front wheel spin. On uniform surfaces however, the coupling can not
transfer all torque to the rear axle. See below.



[/ QUOTE ]

What the quote above means is that with the drive being 50:50, then theoretically, with the Haldex engaged and all four wheels travelling at the same speed and the fronts can't get any grip(front wheels on ice), then all the suppose drive/power is left to the rears if it were in contact with tarmac. Make sense?

 
So what does the blue haldex controller do compared to the standard one
 
Interesting read thanks tuffty, bit of a shocker though when you get to the bottom and see the price lol