RE: Audi Sport Diff Takes Off

[juliofa]

I'm sure they try but look at the video in http://www.drivers-republic.com/dr_tv/

[dieseltaylor]

Lets see, more and more crowded roads, more speed limits so lets add extra complexity to make the cars go faster around corners. Winner idea.

The trouble with Germans is that they are slaves to the technical possibilities rather than the practical and commercially sensible. In tightened times with cheap travel coming from the third world - and even Rumanian Renault I think that Audi are in danger of disappearing up their own exhaust - sort of fundamentally flawed. : )

I hate to think of the on-costs of older Audi's with all the added complexity to potentially go wrong.

[FesterNath]

toohuge said:

kambites said:

daveco said:

Why don't Audi just place the engine further into the engine bay on the RS models? This would help a fair amount to alleviate understeer.

Actually why do they position the engine that far forward?

I think it's to do with now the centre diff is arranged with Quatro. I was under the impression that the new A4 platform pushed the engine behind the axle line though, I'm sure I read that somewhere?

Yes, the a4's engine is mounted behind the front axle. By mounting the engine further away from the cabin, it creates a lot more room.
Personally, i am not convinced by all this electronic differential business.

That's not correct. In the latest iteration the engine is further back than before, but only by a small amount: the change is that the drive shafts exit the gearbox ahead of the clutch, not behind it. Very few front engined cars have the engine behind the front axle. Examples that do are McMerc SLR and a Caterham 7.

[collateral]

FesterNath said:

toohuge said:

kambites said:

daveco said:

Why don't Audi just place the engine further into the engine bay on the RS models? This would help a fair amount to alleviate understeer.

Actually why do they position the engine that far forward?

I think it's to do with now the centre diff is arranged with Quatro. I was under the impression that the new A4 platform pushed the engine behind the axle line though, I'm sure I read that somewhere?

Yes, the a4's engine is mounted behind the front axle. By mounting the engine further away from the cabin, it creates a lot more room.
Personally, i am not convinced by all this electronic differential business.

That's not correct. In the latest iteration the engine is further back than before, but only by a small amount: the change is that the drive shafts exit the gearbox ahead of the clutch, not behind it. Very few front engined cars have the engine behind the front axle. Examples that do are McMerc SLR and a Caterham 7.

Nope, there are quite a few FMR cars

[Kawasicki]

I am not 100% sold on the logic of these diffs. Adding kinetic energy to a car that is near the limit, is that a good strategy for a road car? What happens if the grip level deteriorates further round the bend?

[chevy-stu]

MonkeyMatt said:

fluffnik said:

Neomagic said:

Not quite since, there many more variables in all the systems of the car.

It seems to use all the same inputs and do the same thing as the system in my 13 year old Mitsubishi...

...probably there to counteract the nose heavy understeeryness just like it does (rather well) in my 13 year old Mitsubishi.

The only thing I don't have is the variable damping.

ETA: ...or funky steering

Edited by fluffnik on Thursday 7th May 17:12

So its like you old Mitsubish only newer and better with more features

It looks very similar to Mitsubishis AYC as seen on VR4's and then on Evos.. On them it's a very clever effective set-up and does steer you round the bends..

Wonder if the new Audi design requires the 4500 mile fluid changes like the Mitsi does..

[Not-All-Here]

Only downside I can see is if it goes wrong its going to be expensive, Especially if it goes wrong when its out of warranty.

[fluffnik]

MonkeyMatt said:

So its like you old Mitsubish only newer and better with more features

Yup.

It's a good system, as implemented by Mitsubishi, effectively counteracting the nose heaviness and tendency to understeer of the base FWD car and producing something balanced and pointy in its place.

It's a little unsettling in operation due to the feeling that it's tucking both ends of the car in at once, and I'd like to find out what happens when the AYC's capacity is exceeded somewhere spacious before testing its limits on the road, but it undoubtedly makes a big car more nimble than it has any real right to be...

If Audi's system works near as well it will be a Good Thing.

Edited by fluffnik on Friday 8th May 15:28

[SleeperCell]

collateral said:

FesterNath said:

toohuge said:

kambites said:

daveco said:

Why don't Audi just place the engine further into the engine bay on the RS models? This would help a fair amount to alleviate understeer.

Actually why do they position the engine that far forward?

I think it's to do with now the centre diff is arranged with Quatro. I was under the impression that the new A4 platform pushed the engine behind the axle line though, I'm sure I read that somewhere?

Yes, the a4's engine is mounted behind the front axle. By mounting the engine further away from the cabin, it creates a lot more room.
Personally, i am not convinced by all this electronic differential business.

That's not correct. In the latest iteration the engine is further back than before, but only by a small amount: the change is that the drive shafts exit the gearbox ahead of the clutch, not behind it. Very few front engined cars have the engine behind the front axle. Examples that do are McMerc SLR and a Caterham 7.

Nope, there are quite a few FMR cars

Someones even made a list, which seems to include the majority of modern front engined sports cars.
http://en.wikipedia.org/wiki/FMR_layout

[SleeperCell]

brogenville said:

So they've basically come up with active yaw control (albeit under a different name), as designed by mitsubish oh... 13 years ago?

Yep, all those 'e' diff things that Ferrari, BMW and everyone else have been banging on about for the past few years are also basically the same thing, but only for 2wd. Honda had a similar diff on the front wheel drive Prelude a year after mitsubishi called ATTS, and they've been in motorsports for a while as well.

Arguably Porsche first came up with it in the 959, which had an electronically controlled AWD system, although I'm not sure it was sophisticated enough to apportion torque to individual wheels, merely to front and rear. The Nissan Skyline GT-R R32 was probably the first car produced in numbers to get the technology.

[kambites]

SleeperCell said:

Someones even made a list, which seems to include the majority of modern front engined sports cars.
http://en.wikipedia.org/wiki/FMR_layout

Including the mighty Reliant Robin.

[FesterNath]

collateral said:

FesterNath said:

toohuge said:

kambites said:

daveco said:

Why don't Audi just place the engine further into the engine bay on the RS models? This would help a fair amount to alleviate understeer.

Actually why do they position the engine that far forward?

I think it's to do with now the centre diff is arranged with Quatro. I was under the impression that the new A4 platform pushed the engine behind the axle line though, I'm sure I read that somewhere?

Yes, the a4's engine is mounted behind the front axle. By mounting the engine further away from the cabin, it creates a lot more room.
Personally, i am not convinced by all this electronic differential business.

That's not correct. In the latest iteration the engine is further back than before, but only by a small amount: the change is that the drive shafts exit the gearbox ahead of the clutch, not behind it. Very few front engined cars have the engine behind the front axle. Examples that do are McMerc SLR and a Caterham 7.

Nope, there are quite a few FMR cars

The fact that a Z4 is on that list shows it for what it is. A lot of those cars may have engines partly behind the front axle, but not completely. Which is what was stated above.

[dinkel]

Not-All-Here said:

Only downside I can see is if it goes wrong its going to be expensive, Especially if it goes wrong when its out of warranty.

http://www.youtube.com/watch?v=IElqf-FCMs8&feature=em-uploademail