Subaru AWD Vs. Audi Quattro

[MrX]

Okay, I was under the impression that Subaru's AWD system was just like the Audi Quattro. All wheels working all the time, and when one slips, the other three automatically get a transferance of power to make up for the one that isn't working. Well, today I was told that thats true for the quattro, but Subaru's AWD is nothing more than front wheel drive until there is loss of traction, which is when the power is transfered to all 4?! Is that True?!

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[JC]

No, Subaru's, at least sticks, are a 50:50 split.

[kevinsUBARU]

Subies auto trannys are 90front/10rear when driving (the selector in D, and 3) but this changes around..thats just the norm. When you put it in R, 2, or 1 its a 50 50 split. The 5-speeds are 50-50. So to answer your question, if subie AWDs were FWD till the grip was lost, I would be getting a lot better than 25-26MPG.

Kevin http://SubaruAWD.cjb.net

[goten]

the auto tranny of subaru is 100:0 and can change up to 60:40

the high performance auto tranny ( the ones use in 240HP WRX) can change from 35:65 or 60:40

high preformance manual (WRX. not 2.5RS) is 50:50

the 2.5RS is probably 60/40

[AutoXr]

The question asked, I beleive, was regarding power to each wheel vs just the front to back power split. In reply, I think that the limited slip rear in the newer RS's and similar transfer case (center) provide something very close, but not quite the same as the Audi. A limited slip front diff would be required to duplicate the Audi Quattro on a Subaru, but I maybe not. Some of the more technically astute readers may know something I don't.

I don't think that it matters to 90% of Subaru drivers unless they drive a considerable amount of time in heavy snow/ice or on very muddy roads.

[markus]

Okay, I'm stickin' my neck out for this one.

Simple fact of the matter is that Subaru manufactures more variations of AWD than any other manufacturer...period.

The Audi's use torsion biasing differentials that will allow the power to be sent to individual wheels. Subaru has systems that perform similar to this, but not in really in North America.

The Y2K Legacy GT and Impreza RS models have limited slip rear ends which means there is can be transferrence of power from side-to-side in the rear, but, it an open diff in the front.

Also, Audi's AWD systems are very heavy in comparison to the Subie systems. IIRC, the Subaru AWD systems only add about 150lbs to the overall weight of a car in comparison to when they used to sell FWD cars. For Audi's, it is my understanding that the Quattro systems add around 500+lbs (does someone know the actual numbers?)and are also more elaborate and more expensive (therefore more expensive to fix if something happens).

The correct power split for North American (NA)Subie AWD systems are:

- 90:10 for AT with potential for 100:0 to 0:100 with the electronically controlled 4-disc clutch pack centre diff(6-disk versions available in higher output versions outside of NA)
- 50:50 for MT with potential for 90:10 or 10:90 with viscous centre diff in NA market. There are many, many variations on the MT AWD systems outside of NA.

This is my understanding of how the NA systems are presently set-up.

Mrx, you'll probably find that as far as "bang-for-your-buck" is concerned, the Subie AWD systems are unsurpassed.

My 2cents.

Peace,
MB

[This message has been edited by markus (edited September 14, 2000).]

[The_extreme]

Audi's system is superior - sorry - first hand experience - If I could afford a short wheel base quattro coupe turbo at the moment I'd be there -

Just my 15 Pfennigs worth

Jeff

[MikeYOX]

300 lbs. not 500+(that would be insane! )

[markus]

I agree that the Audi systems are superior to the AWD Subie systems, especially compared to what is offered in NA. But since the Audi systems are so expensive, and their additional capabilities can really only be harnessed at 9/10th's and 10/10ths driving, I think the Subie systems are very comparable.

If Audi ever comes back into WRC racing, this arguement could be settled within a season or two.

[Shin RS]

I hate to admit it, but the audi's system, at least when compared to any of subarus american awd systems is supposed to be superior. Torsen diff vs. viscous coupling, the torsen is supposed to work faster than a viscous lsd... But, like it was said, you'd only get that performance at 10/10ths driving, and also, the american subaru lsd is alot lighter and cheaper than the audi...

[Snoopy]

http://www.eskimo.com/~eliot/awd.html

This is an excellent EXCELLENT site for understanding the difference between torsen(superior yet heavier and more expensive) and viscous coupling(cheaper, lighter yet gets you where the Audis can go too).

Print it out for educational toilet reading. I'll quiz you tomorrow.

[Impresario]

Just to reiterate one point, the automatic Subarus, under normal conditions, have a 90:10 distribution until traction is lost. not 100:0 as someone stated previously. This is the reason that auto Subies get better gas mileage than manual ones.

[Jon Bogert]

The Torsen center diff does, in fact react a little bit more quickly than a viscous diff. It even supposedly transfers torque slightly before a wheel slips. But that's where the advantage ends.

Audi disadvanges include:

- No limited slip when off throttle.

- Much heavier. Much more nose heavy.

- "Spider Bite" windup reaction when just at the limits of traction while turning. See quattro list archives for exhaustive discussion of this.

- Silly ABS "active differential" (yeah right) on quattro IV. I'll decide when to brake and when to accellerate, thank you.

BUT, it's really a matter of preference. Obsessing on the exact torque spilt misses the point: How does it feel going down the road? For balls-out driving, I'll take the handling of a Celica Alltrac or Impreza any day over quattro III or IV.

[Gambit]

Hey how about that VDC thingy on the new Outbacks? Would those help?
BTW, only ppl with their last names that ends with "nens" would harness the extra capability of the Audi AWD system.