[Damn True]

Anyone know the difference in the systems? How they work? Which one is better for which situations?

Kinda funny, I was looking through the new A4 catalog and they only gloss over the technology in the most superficial way. Wierd, Quattro is the thing that defines and differentiates Audi more than anything else. You'd think they'd emphasize it more.

 

[BillT]

There are actually several different systems from each manufacturer.

Over the last several years Audi has started calling both their all wheel drive systems 'Quattro'. The first system is made by a company called Haldex and it is found in the Audi TT - this system is basically front wheel drive (90/10 front/rear split of torque) until slippage is detected and it then will direct more power to the rear as needed. Audi's second system is the traditional Quattro system that you find in the A4, A6, A8, etc. This is a pretty technically complex with 3 different differentials - a center torque sensing differential to direct power front and rear as needed and front and rear electronic differentials to direct power left/right as needed. The real Quattro system is very good at providing traction where it is needed.

Subaru also has severl AWD systems. The first system, Active AWD found in most of their automatic transmission equiped cars (Forester, non WRX/STI Impreza, non-turbo Legacy/Outback) and it operates very similar to the Haldex system. The second system is called Continuous AWD. This system is found in most of Subaru's manual transmission cars with the exception of the STI. This uses a mechanical viscous center differential to split power 50/50 front and rear. Once slippage is detected, the system will react and send power to the wheels with traction. On the WRX, there is a rear limited slip differential to further get traction down. The last system Subaru uses is VTD (Variable Torque Distribution). This system is most closely related to Audi's Quattro system as it uses electronics to vary the power front/rear. This system is found in automatic WRX's and I believe higher end Legacy/Outback models. The STI uses a version of this system but has both front and rear limited slip differentials as well as the ability for the driver to select how much power to send front/back.

All the sytems are very good with the Quattro probably being the 'best' albeit the most complex as well. The Continuous AWD system that Subaru uses is very simple and probably the most bomb-proof.

 

[ZEDMAN]

um get an evo and do this........ http://www.srvidz.com/chrisevo.wmv

35 pounds of boost and a stroker kit, lets just say its fast........

 

[MTB_Rob_NC]

um get an evo and do this........ http://www.srvidz.com/chrisevo.wmv

35 pounds of boost and a stroker kit, lets just say its fast........

Ah rarely do I miss my DSM days, but that is a nice Evo.

 

[BillT]

If I had a ton more disposable income, I'd love to buy an Evo and mod the crap out of it...maybe one day.

 

[Damn True]

um get an evo and do this........ http://www.srvidz.com/chrisevo.wmv

35 pounds of boost and a stroker kit, lets just say its fast........

Er....no thanks.

 

[Damn True]

There are actually several different systems from each manufacturer.

Over the last several years Audi has started calling both their all wheel drive systems 'Quattro'. The first system is made by a company called Haldex and it is found in the Audi TT - this system is basically front wheel drive (90/10 front/rear split of torque) until slippage is detected and it then will direct more power to the rear as needed. Audi's second system is the traditional Quattro system that you find in the A4, A6, A8, etc. This is a pretty technically complex with 3 different differentials - a center torque sensing differential to direct power front and rear as needed and front and rear electronic differentials to direct power left/right as needed. The real Quattro system is very good at providing traction where it is needed.

Subaru also has severl AWD systems. The first system, Active AWD found in most of their automatic transmission equiped cars (Forester, non WRX/STI Impreza, non-turbo Legacy/Outback) and it operates very similar to the Haldex system. The second system is called Continuous AWD. This system is found in most of Subaru's manual transmission cars with the exception of the STI. This uses a mechanical viscous center differential to split power 50/50 front and rear. Once slippage is detected, the system will react and send power to the wheels with traction. On the WRX, there is a rear limited slip differential to further get traction down. The last system Subaru uses is VTD (Variable Torque Distribution). This system is most closely related to Audi's Quattro system as it uses electronics to vary the power front/rear. This system is found in automatic WRX's and I believe higher end Legacy/Outback models. The STI uses a version of this system but has both front and rear limited slip differentials as well as the ability for the driver to select how much power to send front/back.

All the sytems are very good with the Quattro probably being the 'best' albeit the most complex as well. The Continuous AWD system that Subaru uses is very simple and probably the most bomb-proof.

Thanks.
Last weekend my GF and I were out test driving cars and when we were in the Audi she looked at me and asked, "So whats the difference between this system and your Outback?" and I was like, ".........................uh.....about $20k. But I'm sure there is more to it than that." Which as you might imagine did nothing for the image she holds of me as the tech savvy gearhead. Of course, the salesman was useless too.

 

[Sandwich]

Really, they aren't much different. The audi is certainly more sophisticated, but does that matter much? My 83 Ur goes through 7" of powder just fine, thanks. I imagine a limited slip would be better on dry pavement, but you'll probably never see a different.

http://www.audifans.com/twiki/bin/view/Audi/QuattroGenerations
see here for more info.

The best thing to have is generally 3 LSD's or torSens, as each wheel is given a better, more reliable amount of power. I don't really like the idea of electronics in the drivetrain....something just doesn't seem right with that. i would avoid Haldex at all costs, but you probably will never be able to tell the difference between an audi and a subie, on the road.

PS, quattro is AWD, just with a fancy name. Same thing with subaru's "Symmetrical AWD". Same thing, just add letters and numbers until consumers get confused.

 

[SkaredShtles]

Really, they aren't much different. The audi is certainly more sophisticated, but does that matter much? My 83 Ur goes through 7" of powder just fine, thanks.

You BAHSTID!! :mumble:

I owned an old '85 4000S Quattro and two Subarus ('95 Legacy wagon, '97 Outback wagon) and I have to say the Quattro was the most fun to drive in crappy traction conditions. It was alot more "predictable" than the Sube's.

I could take the Audi into a snow covered hairpin going up a pass and keep it under continuous power - the car would predictably oversteer. As long as you stayed on the power you could basically powerslide through the turn.

My Sube's aren't/weren't nearly as predictable. They seem to understeer quite a bit more, which is disconcerting when you need to get the ass end around under power.

That being said, the Sube's are still excellent in the snow. I wouldn't buy an Audi mostly because of the maintenance issues. I got pretty lucky with mine (nothing major), and it was cheap.

-S.S.-

 

[Sandwich]

:eviltongu
http://community.webshots.com/album/287228202ULWUTp
:devil:

 

[SkaredShtles]

:eviltongu
http://community.webshots.com/album/287228202ULWUTp
:devil:

BAHSTID!

-S.S.-

Edit: I bet that thing is a fuggin' HOOT in the snow..........

 

[Westy]

You BAHSTID!! :mumble:

I owned an old '85 4000S Quattro and two Subarus ('95 Legacy wagon, '97 Outback wagon) and I have to say the Quattro was the most fun to drive in crappy traction conditions. It was alot more "predictable" than the Sube's.

I could take the Audi into a snow covered hairpin going up a pass and keep it under continuous power - the car would predictably oversteer. As long as you stayed on the power you could basically powerslide through the turn.

My Sube's aren't/weren't nearly as predictable. They seem to understeer quite a bit more, which is disconcerting when you need to get the ass end around under power.

That being said, the Sube's are still excellent in the snow. I wouldn't buy an Audi mostly because of the maintenance issues. I got pretty lucky with mine (nothing major), and it was cheap.

-S.S.-

Pretty much most modern cars are tuned understeer under power no matter the AWD config. My brothers S4 will understeer under power just like my WRX, to over steer you have to close the throttle in the corner. Now the STi has the adjustable power center diff that will let you put more power to the rear and power drift through corners.

 

[SkaredShtles]

Pretty much most modern cars are tuned understeer under power no matter the AWD config. My brothers S4 will understeer under power just like my WRX, to over steer you have to close the throttle in the corner. Now the STi has the adjustable power center diff that will let you put more power to the rear and power drift through corners.

You know, the old Quattro had a switch which allowed you to lock the center diff, and another to lock the rear diff (for when you *REALLY* got stuck). I don't think the newer ones have this feature any more. All that stuff is probably electronically controlled by some computer.

Understeer sucks.

-S.S.-

 

[mack]

I think that the STI should come with lockers.

Would that be good in snow? Arent rally cars locked drive trains? Does this more power to one wheel thing actually help in the snow, it seems to me that 50/50 power split would work the best.

 

[Sandwich]

the sti probably should come with lockers, just in case, but in reality a good LSD is better than lockers. The problem with an open diff (most awd cars) is that with one wheel in the air or on ice, ALL the power goes to that tire. If you can lock either the center or the rear, you can force power to go to another tire. I've gotten stuck in our (really steep) driveway once because of that. The lockers on old audis DO NOT work very well (if at all). I tried using them when the car was moving (in deep snow) and noticed no difference with the switch thrown or not, so I have reason to believe they were not working. The car still handled just fine, however.

Yes, locked diffs are good in the snow and dirt, but terrible on pavement. Modern rally cars use "intelligent" or active diffs, which are essentially LSDs with computer controllers (think k2 smartshock) that control torque bias. They work excellently, but can cost as much as half the car itself. This is why you see some teams opt for mechanical diffs (ie LSDs or TorSens) when they are testing a car (eg Mitsubishi).

The OLD rally cars didn't have that benefit. They generally used a locked center and two open diffs, or a center and rear locked. This ensured all wheels would have power on all surfaces. Did it work? These were some of the fastest and most insane cars in the world. One (the lancia delta S4, i think) would have posted the 4th fastest qualifying time for F1 of that year. Still, they would be even faster (and maybe still around) if they had today's technology.

 

[mack]

You have that AND the frigen pimp truck? bastard.

I either want the toyota or a subi for a firt car. Still waiting for the money.


this looks like a fun 323.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6319&item=4545613754&rd=1&ssPageName=WDVW

 

[MTB_Rob_NC]

I either want the toyota or a subi for a firt car. Still waiting for the money.


this looks like a fun 323.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6319&item=4545613754&rd=1&ssPageName=WDVW

Buy a DSM over a 323 any day. They are faster, newer, stronger with more available parts (new and used).

 

[SkaredShtles]

<snip> The lockers on old audis DO NOT work very well (if at all). I tried using them when the car was moving (in deep snow) and noticed no difference with the switch thrown or not, so I have reason to believe they were not working. The car still handled just fine, however.

They must not have actually been engaging then (broken?). I got my 4K buried pretty well once (it doesn't take tons of snow to bury a little car with ~3" of ground clearance), and couldn't get it out with the center locked. When I locked the rear diff the car crawled right out of the snow.

-S.S.-

 

[BillT]

The WRC rally cars (with the exception of the Mitsubishi entry) all use very expensive, high-tech electronic differentials to ensure that the power is reaching the wheels with the most traction.

One of the other reasons why Audi's in general understeer so badly is that the design of their Quattro system means that the entire engine has to sit in front of the front axle which makes them extremely nose heavy and prone to nasty understeer.

 

[Sandwich]

same thing with the subaru though, longitudinal boxers...


yeah, the vacuum lines that connect them weren't engaging the switches. I might rig up some cable pulls.

 

[luken8r]

FYI the A3 with 3.2L quatro and DSG is coming here in january. likely for around 30k

 

[BillT]

same thing with the subaru though, longitudinal boxers...

True, but at least the boxers sit a little lower than conventional engines and they are 2.0L to 2.5L aluminum block engines as opposed to Audi's 1.8L and 2.0L iron block engines and their 3.2L and 4.2L aluminum block v-6's and v-8's.

 

[mack]

Why do so many people (exception being toyota) prefer air lockers like ARB. I know that you can turn them on and off, but why not use a cable instead of $ air lines? Toyota uses a electronic motor, but the wheels have to turn a few times in order for it to lock. Not so sure about the mitsubishi factory lockers though.

 

[Sandwich]

Why do so many people (exception being toyota) prefer air lockers like ARB. I know that you can turn them on and off, but why not use a cable instead of $ air lines? Toyota uses a electronic motor, but the wheels have to turn a few times in order for it to lock. Not so sure about the mitsubishi factory lockers though.

might have to do with the amount of pressure...an air (vacuum in my case) line will put a finite and controllable amount of pressure. Some jerk with a cable will pull as hard as he wants to. The diff doesn't lock immediately, however, it needs the teeth to line up...so you'd have to pull the cable and hold it until the wheels can align, which may take a minute or two. With the air/electric system, it's pull and drive, hands back on the wheel.

Then again, asking why audi does something foolish with their cars is like asking why coconuts are at the top of the tree, or why sugar comes from a cane, or why rubber from a tree. It just is, and it just does. Who on earth would think to use a 5 cylinder engine, when six is more balanced and 4 is more compact? Why put ALL of the engine's mass BEFORE the front wheels? Such is the logic(magic?) that is audi.

 

[BillT]

The 3.2 A3 will probably start around $30k, but once you hit a couple of option boxes, you'll probably be closer to $35k than $30k.

 

[mack]

The audi rally cars have the engine moved back about 4 inches so the understeer is not so bad. Why dont they just follow subaru with a compact 4cyl boxxer? Does the SCCA allow mid engine drive cars?

I guess the v6 and v8 badge sells the cars.

What other stupid things are audi's known for? I always thought Audi had a good reputation.

 

[SkaredShtles]

<snip>

What other stupid things are audi's known for? I always thought Audi had a good reputation.

Broken door handles. Electric window switches that randomly work/don't work. Broken shift boot housings.

Other random electrical nightmares.

I :heart:ed my Quattro, though - despite the issues.

-S.S.-

 

[mack]

Well, i can certantly vouch for subarus. We have a 91 legacy, it has 225 k miles on it. The only thing that doesnt work is that the ceiling is falling down and the rims have so many holes/dents that all tires have tubes in them. But the engine is only on its second seal job and doesnt burn anything, turbo is original and steady PSI.

 

[SkaredShtles]

Well, i can certantly vouch for subarus. We have a 91 legacy, it has 225 k miles on it. The only thing that doesnt work is that the ceiling is falling down and the rims have so many holes/dents that all tires have tubes in them. But the engine is only on its second seal job and doesnt burn anything, turbo is original and steady PSI.

Dude - you're vouching for *old* Subarus.

Which I can do, too.

I've heard the newer ones are a bit more problematic, on average.

-S.S.-

 

[BillT]

44k trouble free miles on my '02 WRX wagon.

 

[Bullitrider]

http://www.dahlbackracing.se/english/main.asp

Go to the gallery and check out the black Quattro. That thing is insane! :evil:

 

[SkaredShtles]

http://www.dahlbackracing.se/english/main.asp

Go to the gallery and check out the black Quattro. That thing is insane! :evil:

Ummmm...... *which* black Quattro:

-S.S.-

 

[Bullitrider]

Left side, second from the bottom.

 

[mack]

Do i smell sequential shift?

HOT!


Look at the other photos, that thing is a race machine...

Fuel tank, hoses, turbo and exaust manifolds, everything is done proper.


Edit: Is that radiator mounted like that stock, or did they move it?

Also, what is the purpose of this radiator? To cool the differentials down?

 

[Bullitrider]

Not sure if they moved it or not but I would assume you are correct about the differentials. Eurotuner did a blurb on Dahlback and said this thing gets 500+ hp.

 

[manhattanprjkt83]

Wow i cant believe someone started this thread, I am just graduating school and am about to buy a car. My choices

2001 Audi S4 neggaro blue...:tounge:

or

2004 Subaru STI


I know this sorta seems like a no brainer (sti) but i just dont like the styling on the car that much. I want to be smart and go with it because of the flat out performance....


opinions 's

 

[SkaredShtles]

Wow i cant believe someone started this thread, I am just graduating school and am about to buy a car. My choices

2001 Audi S4 neggaro blue...:tounge:

or

2004 Subaru STI


I know this sorta seems like a no brainer (sti) but i just dont like the styling on the car that much. I want to be smart and go with it because of the flat out performance....


opinions 's

I'd go with the S4. Yum.

-S.S.-

 

[merrrrjig]

Get the WRX Its such a sicker car!

 

[manhattanprjkt83]

Yeah i know the s4 is juicy esp in that color, i am a huuuuuuuuge euro fan but the STI is one hell of a ride performance wise, im torn...

this is a huuuuuuge purchase, any advice would really help

 

[BillT]

If this is a huge purchase (indicating you may be stretching a bit to afford it), I would recomend the Subaru because it should be much more reliable than the Audi. The 2.7L twin turbo in the Audi can make some huge power, but the reliability of car is pretty suspect and anything that brakes will cost big $$$ compared to the Subaru. With the STI you'll have to worry about replacing the tires (they are practically r-compound race tires) and the brake pads as they both tend to go fast.