Audi RS5 new Quattro System

[RyanGT]

Audi no longer uses the Torsen center diff for the RS5. The RS5 has the 450hp V8 engine. The new quattro uses a Crown Gear Center differential with Torque Vectoring.

 

Watch this youtube video:

 

[ame=http://www.youtube.com/watch?v=m4OWjX3tDYA]YouTube- Audi: The quattro principle[/ame]

[Bbc84]

Looks neat but I dont know if I like it using brakes for torque vectoring

[SLegacy99]

Ugh, I want an Audi.

[f1anatic]

I have a friend who just got a 2010 Audi S4; I wonder if it came with Torsen or Crown ?

[EvoFire]

I don't like all these new systems with so-called torque vectoring. All it does is brake the inside wheel for you. The VW GTI's XDS(I think that's what its called) works, but however when you drive it hard it will end up cooking the brakes.

 

Honestly if you are going to do side-to-side torque vectoring, do it the proper way like Mitsubishi has with their S-AWC.

 

Subie's symmetrical system works well and its simple. But Mitsubishi's S-AWC is where all the technology is, none of that braking the inside wheel garbage.

[NSFW]

Anyone else find it funny that Audi keeps changing fundamental aspects of their AWD system, and still keeps calling it "Quattro" year after year? Quattro means something different every time I hear about it, which basically means that the word "Quattro" means nothing. It's just AWD, implemented however Audi felt like implementing it that year.

 

Branding is a funny thing.

[IwannaSportSedan]

Quattro is a brand name for Audi's AWD system (possibly a sub-contracted supplier, or in-house engineering division), not the name of a particular system.

 

I'd be suspect if they weren't trying to make progress and update with newer, better technology, as long as they test it and prove it's reliability.

 

Technically symmetrical AWD for Subaru refers to several systems that all resemble the same layout, btw. Various torque bias profiles, various capabilities to shuffle torque from front to rear and such.

 

 

That coaxial crown-gear differential is very slick. I hope that gets wider adoption. Seems a bit like Subaru VTD on steroids, with the electronically controlled clutch wrapped right into the differential casing.

 

Autoblog just the other day mentioned that R8 may be getting an upgrade to a sportier model, and possibly getting DSG, instead of R-tronic from the Lambo.

 

If they were to spec an Audi R8 4.2 similar to the RS5... 450hp or more out of the V8...

Plus, if they add a true dual-clutch gearbox, that is both quicker than a manual, and just as directly driven...

Plus an upgrade from the current AWD system that is basically Haldex in reverse, (clutch or viscous PTO for the front wheels of the Lambos/R8, rather than for the rear wheels like the TT and A3Q)

 

With this sort of crown-gear differential included, R8's AWD would be just as capable as RS5. They would have to re-calibrate the output balance to be reversed, with the transaxle's rearward, rather than forward location, as well the inherent mid-engined rearward weight bias, and handling characteristics. (maintaining a rear-bias, but the rear wheels connect to the transaxle in the back of the car. The front wheels get the separate axle diff)

 

The torque vectoring is iffy. I tend not to like using the brakes for everything... but I have to admit, it is less equipment, complexity, and weight involved than to pack clutches into the axle differentials, to basically do the same exact thing anyway.

 

SH-AWD does torque vectoring on some models, like the Acura RL, but packs electronic clutch packs into the differential case, making that assembly more complex, with more service and potential failure points.

 

The brakes already exist on the axles, and do the same job, to apply impedance to half of the axle's rotation per brake.

 

They already use brakes for stability control, as well, so essentially using the brakes for torque vectoring is a matter of software. Independent braking control infrastructure and electronic control system is already in place, it is just learning additional functionality, with no more electronic, hydraulic, or physical hardware than what was already there.

 

I suppose if you are going to wear through brake pads with stability control anyway, might as well use them for torque vectoring also, and get some benefit, not just safety net. Brake pads and discs are probably easier and less costly to service than servicing a differential with lots of moving clutch packs inside... those tend to require precision setup and pre-loading work by expert techs, and are probably easy to foul-up if done incorrectly.