When does AWD activate in the S3? Haldex questions....

[drew4392]

I have been reading a bit on Haldex (http://torquingcarsonline.com/genera...hat-is-haldex/) and still have a couple of lingering questions.

Do the rear wheels only receive power when slip is detected? If that is the case, isn't that too late? My thinking is if I'm already in a slide or losing traction, rear drive suddenly kicking in would disrupt balance and do more harm than good.

I was also thinking about the FWD state of Haldex yesterday in the rain. In my S4, total confidence. In a S3, it's only FWD until some sort of trigger initiates the rear wheels. Not terribly confidence-inspiring.

I'm very strongly considering a S3, so this is me trying to learn, not troll in the slightest sense.

Haldex is a lot lighter and these things might just be the way it is. If I'm mistaken, please help clarify.

Thanks!!

[ENV²]

I have been reading a bit on Haldex (http://torquingcarsonline.com/genera...hat-is-haldex/) and still have a couple of lingering questions.

Do the rear wheels only receive power when slip is detected? If that is the case, isn't that too late? My thinking is if I'm already in a slide or losing traction, rear drive suddenly kicking in would disrupt balance and do more harm than good.

I was also thinking about the FWD state of Haldex yesterday in the rain. In my S4, total confidence. In a S3, it's only FWD until some sort of trigger initiates the rear wheels. Not terribly confidence-inspiring.

I'm very strongly considering a S3, so this is me trying to learn, not troll in the slightest sense.

Haldex is a lot lighter and these things might just be the way it is. If I'm mistaken, please help clarify.

Thanks!!

I am not a pro on haldex but what I do know is I believe they make Haldex controllers where you can make it a much more fun system.

[HurrayFive]

I have been reading a bit on Haldex (http://torquingcarsonline.com/genera...hat-is-haldex/) and still have a couple of lingering questions.

Do the rear wheels only receive power when slip is detected? If that is the case, isn't that too late? My thinking is if I'm already in a slide or losing traction, rear drive suddenly kicking in would disrupt balance and do more harm than good.

I was also thinking about the FWD state of Haldex yesterday in the rain. In my S4, total confidence. In a S3, it's only FWD until some sort of trigger initiates the rear wheels. Not terribly confidence-inspiring.

I'm very strongly considering a S3, so this is me trying to learn, not troll in the slightest sense.

Haldex is a lot lighter and these things might just be the way it is. If I'm mistaken, please help clarify.

Thanks!!

Having owned both (Torsen Quattro in the 5 and Haldex Quattro in the 3), just drive one. In normal driving and even raining wet roads the Haldex is seamless. The differences show when you're used to the 60/40 rear split of Torsen, controlling the rear end with throttle goes away. People have also said it's more difficult to drive in snow, but I have no snow here, so I can't compare.

The latest generation of Haldex always has at least some engagement in the clutch pack, which equates to ~97% to the front wheels and ~3% to the rear wheels under "normal" conditions (cruising down the road). The latest generation also does not wait for slip to occur but actually pre-senses slip conditions based on throttle input, steering angle, and a whole number of other things. It will preload the clutch pack in anticipation of slip so that application of power is near seamless. In rear world hard driving you can tell it's an AWD car because you can dive into a corner with too much power and let traction pull you out as you'd expect, the difference is how the rear of the car rotates (or lack of it). For me it's far from a deal breaker, and with Stage 2 power it's still possible to get the car sideways, but it's not a rear drive dominant car like you'd be used to.

[drew4392]

Having owned both (Torsen Quattro in the 5 and Haldex Quattro in the 3), just drive one. In normal driving and even raining wet roads the Haldex is seamless. The differences show when you're used to the 60/40 rear split of Torsen, controlling the rear end with throttle goes away. People have also said it's more difficult to drive in snow, but I have no snow here, so I can't compare.

The latest generation of Haldex always has at least some engagement in the clutch pack, which equates to ~97% to the front wheels and ~3% to the rear wheels under "normal" conditions (cruising down the road). The latest generation also does not wait for slip to occur but actually pre-senses slip conditions based on throttle input, steering angle, and a whole number of other things. It will preload the clutch pack in anticipation of slip so that application of power is near seamless. In rear world hard driving you can tell it's an AWD car because you can dive into a corner with too much power and let traction pull you out as you'd expect, the difference is how the rear of the car rotates (or lack of it). For me it's far from a deal breaker, and with Stage 2 power it's still possible to get the car sideways, but it's not a rear drive dominant car like you'd be used to.

Makes much more sense-- thanks. I test drove the S3, but not in a way that allowed me to really see the difference. Very old salesman... I felt bad.

[markn1689]

for what its worth i've launch my s3 from 4k rpm in the rain with NO slippage at all.
compared to my b7 s4 they feel the same in that respect. s4 felt more stable on the highway but then again its a tugboat

[aj6]

with Stage 2 power it's still possible to get the car sideways

Can definitely confirm this