AWD comparisons

[Human]

Originally Posted by martinbo

That's cool Human.

I know nothing about the four-wheel drive systems in tractors and combine harvestors. Otherwise, I'd be a moderator on www.worldcombineharvestorfans.com instead.

What I do know a fair bit about is the functioning and mechanical technology of the most recognised all-wheel drive systems in modern road cars. Yes, BMW has made huge in-roads with xDrive - but it's not the be all and end all. No AWD system is, actually, each of them has some or other imperfection - this is the nature of the AWD approach in general.

My point was only that - as with the CABIN AIR FILTER no used in most cars, there is much to learn from agricultural machinary....

[Human]

Originally Posted by martinbo

I don't know the answer to that. I haven't seen the video nor do I believe that it is an AWD system that is getting the X5 off the roller - it is the DTC and ABS working to brake a spinning wheel. Could it be that the X5's software was better than the Audi's?

Point taken and understood - thanks. Then it must be the software...
(No video, I saw it with my own eyes at a demo in Klerksdorp)

The Dynamic Drive differetial is really a masterpiece of engineering, how would you rate it to the AUDI Sport diff. ??

[martinbo]

Agricultural industry? Maybe.

But when it comes to all-wheel drive technology, logically I feel that the size, weight and application of the mechanical componentry on agricultural equipment is just too different from the application in road cars.

It's like saying that the latest hybrid cars should be using electrical motor technology developed for Liebherr Off-highway Trucks. Application is everything.

And right now, the some of the most significant advancements in AWD technology have come from motor racing where the vehicles used are much much closer in application.

[martinbo]

Originally Posted by Human

The Dynamic Drive differetial is really a masterpiece of engineering, how would you rate it to the AUDI Sport diff. ??

I'm getting confused here Human. You talk of Dynamic Drive - which is a suspension control system. I think you're referring to DPC or Dynamic Performance Control, which is an active rear differential.

Yes, DPC rear differential is very very impressive. I believe that it and the Audi sport differential are on a par as they both do exactly the same thing: that is apportion and even boost torque at the loaded rear wheel.

Audi's is made by Borg Warner and BMW's by ZF? Don't quote me I could be way wrong. I need to check or have EnI pitch in.

[martinbo]

Originally Posted by Sayyaaf

How about including the Japaneese into that comparison ? Acura's SH-AWD (Super Handling - AWD), the ATESSA system by Nissan (GTR or Infiniti FX - different setups) ?

I am eager to learn about those systems.

Honda's Super Handling(SH)-AWD is very advanced in that it employs 3 active, multi-clutch differentials that not only apportion torque front to rear but also left to right at each axle. This is quite unusual. Some SH-AWD systems feature a form of torque vectoring where the loaded rear wheel can be overdriven (by up to 6%). Whilst SH-AWD is lauded for its advanced technology, the nett effect of the system on the driving experience hasn't been overly praised by the press. It appears that this system is geared more toward driving safety rather than overtly sporty driving dynamics.

Nissan's super ATTESA system on the GT-R is an altogether different kind of AWD animal. First off, it's a 100% rearwardly-biased system. In static state the rear-transaxle apportions all of the available torque to the rear wheels. Which leads me to another thing: as AWD layouts go, the GTR's is utterly unique. Because the gearbox is housed in a rear transaxle, the GT-R uses two propshafts that run the length of the drivetrain. One shaft runs down the centre to the rear axle gearbox and the other is offset and runs back toward the front axle. Only when the rear wheels start to slip does power get sent back up to the front axle and even then it is in smaller percentages.

[Imhotep Evil]

Originally Posted by martinbo

Honda's Super Handling(SH)-AWD is very advanced in that it employs 3 active, multi-clutch differentials that not only apportion torque front to rear but also left to right at each axle. This is quite unusual. Some SH-AWD systems feature a form of torque vectoring where the loaded rear wheel can be overdriven (by up to 6%). Whilst SH-AWD is lauded for its advanced technology, the nett effect of the system on the driving experience hasn't been overly praised by the press. It appears that this system is geared more toward driving safety rather than overtly sporty driving dynamics.

Not so for older rally cars like Peugeot 2006 WRC.
It can be very, very, very effective if done right. Everybody copied it, once the 206s started to trash the opposition. I was giving some thought if such a solution could help the road course racecars with the rubber line vs. marbles issue.
Any thoughts martin?!