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I think RWD really struggles in the snow and ice. As far as better weather goes, RWD can only reach parity in the dry. In the wet, on gravel, sand on the road AWD excels. And while RWD does do just fine in the dry, every touring car series that has allowed AWD has eventually had to ban it because even stiff weight penalties failed to slow them enough.

On the other hand, RWD can be great fun as it is generally more dramatic. Having all that traction can get boring at times.

C
 

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I agree with Chris here.

Having traction almost all the time tends to be boring, but it also allow faster track time if driven properly.
AWD advantages are as follows:
Better offline acceleration
Can brake deeper and get on the gas a bit sooner in corners
Better overall traction

AWD disadvantages:
Weight
Drivetrain loss are greater than an RWD

RWD is definately more dramatic. True in some cases AWD is superior, but nothing is faster on 2 wheels than an RWD F1 car. There's a bit more skill in driving a high powered RWD vs the same AWD car.
RWD advantages:
Straight line acceleration is very good
less weight
less drivetrain loss

RWD disadvantages:
can't brake as late as AWD in corners, but can accelerate almost just as soon, just make sure your car is almost pointed straight ahead.
high powered cars are hard to drive in inexperienced hands, aka less traction.

Different taste for different strokes. It's hard to compare the two types, as each type has their own strengths and weaknesses. That's why everyone should have one of each! :D
If you never driven a fairly highpowered RWD car, you should go try. If you never driven a fairly highpowered AWD car, you should go try. The difference in driving styles will amuse you.

I personally need an AWD
:D

-LostLamb
 

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Just to add,

Another dissadvantage of awd is understeer. This can be helped by suspension, diffs, etc but it's still gonna be there compared to a rwd car (esp when you want oversteer to rotate the car).

For my daily driver, nothing beats AWD. I love having the control that I do, in all conditions.
 

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You certainly can adjust the balance - especially if you have adjustable diffs (few street cars have them, but most serious AWD racers do).

AWD is specifically banned in F1 - as it is in almost all forms of racing where AWD is not used. It would be interesting to see what the teams would do if it was legal. W/out traction control, I'm fairly certain they would go for AWD. With traction control the outlook is a little more muddy.
 

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Could you give us a synopsis of what they're saying in the Bimmer forum? I don't feel like registering.
 

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I think there should be a breakdown into subcategories of the two groups. FR cars handle differently from MR and RR; meanwhile, there are a few mid(rare) mount and rear mount AWD cars as well. There are even so called "front mid mount" FR cars. Ultimately I'm partial to RWD cars in general as I tend to hate FWD understeer(not that RWD never understeer, but you get it). AWD cars can be tricky is categorising whether they tend to fall into pseudo FWD caracteristics or pseudo RWD.
 

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schischwein said:
AWD cars can be tricky is categorising whether they tend to fall into pseudo FWD caracteristics or pseudo RWD.
Definately. It's kinda in between. It'll rotate with the throttle, but then it'll also go where you point it once it hooks. It's a funny animal. :D
 

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bedabi said:
Have you seen the latest Grassroots Motorsports article about testing an AWD (WRX), FWD (RSX-S) and RWD (BMW 330) car on a track? The 330 had the worst times. I wrote about the article here:
http://www.clubwrx.net/forums/showthread.php?s=&threadid=11193

Funny how people just flat out refused to believe the RWD car was the slowest.
2 things strike me funny about that thread. First, that the RWD Bimmer actually went faster in the wet than the dry ( :confused: ) and second that the guy chiming in for RWD referenced F1 and Le Mans, when of course AWD is specifically banned by the rules from both series/events. And of course it is banned from pretty much every series that AWD does not dominate.

Which keeps me on topic since that's what I said at the top of THIS thread. :D

I do still maintain that RWD is a lot of fun in the dry though.
 

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GV27 said:
2 things strike me funny about that thread. First, that the RWD Bimmer actually went faster in the wet than the dry ( :confused: ) and second that the guy chiming in for RWD referenced F1 and Le Mans, when of course AWD is specifically banned by the rules from both series/events. And of course it is banned from pretty much every series that AWD does not dominate.
I knew you'd have an answer to the F1 and LeMans counterpoint! :D

Yeah, the article never really explained why the wet results were faster. Maybe it was all a typo? Grassroots isn't exactly a high, glossy mag.
 

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Where is the bimmer thread located becouse its giving me an error message when i use the link, but when i go to the site i can go everywhere??
 

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Discussion Starter · #13 ·
It's in the Off-Topic section. Shoot, I forgot you have to register to see the Off-Topic section (sometimes a boobie and buttocks will show up). Well, it's just a few guys who think they know more than they do about the WRX's capabilities. It's not flaming, just uninformed. Feel free to voice your opinions if you feel like registering. Here are some comments.

(Post #3)

If AWD was the true answer to performance, then F1 cars would be AWD.

(Post #7)

I have a friend of mine who thought AWD was the way to go for a track car because of supposed all wheel drive potential. Well... a year and numerous modifications (exhaust, boost controller, intake, full track suspension) he's selling his AWD WRX to buy a RWD vehicle of some sort. I'm trying to talk him into a bimmer, but I think he's going for a old style RS Carrera.

(Post #8)

I think there's a difference between the general characteristics of AWD and the particular characteristics of a WRX. In general, AWD launches and handles better, but it robs crank hp and weighs down the car. Look at AWD Porsches. You can't compare their handling to the WRXs ... it's on an entirely different level.

If you could make an AWD system that didn't weight much over RWD, and didn't drop much hp across the tranny and diffs relative to RWD, I'd be there!

--------------------
I justed wanted some of you guys to set the record straight.
 

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M Roadster+WRX said:

(Post #8)

I think there's a difference between the general characteristics of AWD and the particular characteristics of a WRX. In general, AWD launches and handles better, but it robs crank hp and weighs down the car. Look at AWD Porsches. You can't compare their handling to the WRXs ... it's on an entirely different level.

If you could make an AWD system that didn't weight much over RWD, and didn't drop much hp across the tranny and diffs relative to RWD, I'd be there!

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I justed wanted some of you guys to set the record straight.
Well, you can actually compare Porches 996 Turbo to WRX. Why? Here's the case. The 996 AWD system is an intelligent system, it's not a 50/50 power transfer to all wheels, it's a 40/60, 10/90, and almost anything inbetween. When going in a straight line, the 996 applies most or all its power into the rear wheels. Where as the WRX is a fulltime AWD 50/50 system. Both systems are heavy, and both systems contribute to the drivetrain loss. You can make and adjust an AWD car to handle just as well and an RWD car, if not better. AWD Alfa 155/156 dominated the BTCC series, until ultimately they were banned. Audi dominated in their S4/A4 introduction to the BTCC with their AWD system. No one system is superior. To buy a car because you feel the AWD is dominate is being uninformed.

Just my 02cent

-LostLamb

*is preaching too much...need to lay off the sugar*
 

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I'll second that the 996Turbo is 95% power to rear(5% front) most of the time until things get hairy(then it's 60R/40F).
MRoadster+WRX, my point more about handling characteristics than powerlosses. This is simply because RWD of all variants do not behave the same and in terms of AWD, while many of today's offerings are front mount, not all are, and you have to differentiate the classes because of things like power distribution.
Anyways, I'm happy your friend got a RS Carrera....I'd love to have a Porsche with factory critical seam welds(and a cage-RSR models).
 

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5MT WRX isn't always 50/50. The center diff is limited slip, so it will send more torque to the end with more grip. It's only 50/50 torque split when you are at zero slip.

And that auto WRX's have an electronic system that i don't know much about, but seems to be similar (mechanically) to what the Porsche uses.
 

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bedabi said:

I knew you'd have an answer to the F1 and LeMans counterpoint! :D
It's often a mistake to point to a major international series for a particular part or technology. The rules are very rigid. No AWD, no ABS. In F1 engines can ONLY be 3 liter V-10.

The configurations used are also often forced by other considerations. As an example, "if boxer engines are so great, why aren't they used in F1?". The answer is that they're just too wide and hopelessly compromise the aerodynamic "coke bottle" shape at the rear of the car.

Audi caused AWD to be banned from all major Touring Car championships (though not the USTCC as Gary Shehan can tell you) as it was deemed an unfair advantage, even though they had to adhere to the same engine regulations (working against them) and minimum weight requirements (working for them) as everybody else. WRC is one of the few international series where AWD, FWD and RWD are all treated equally, though it is a moot point as AWD is an overwhelming advantage on slick surfaces.
 

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FUNKED1 said:
5MT WRX isn't always 50/50. The center diff is limited slip, so it will send more torque to the end with more grip. It's only 50/50 torque split when you are at zero slip.

And that auto WRX's have an electronic system that i don't know much about, but seems to be similar (mechanically) to what the Porsche uses.
Just to be clear, the 5MT center diff does not really bias torque to the front or rear, physics does. It allows a certain amount of slip in normal driving, allowing the two ends to move at different speeds as conditions (like turning) dictate. When slip occurs, the center diff starts to lock up. With enough slip it locks up almost completely. In this state, the diff is sending equal power to the front and the rear. BUT since one end has more grip than the other, and the two ends are locked together, the end with more grip gets more power.

To take an extreme example, imagine that the diff locks completely (it doesn't due to the viscous design) and that somehow the front has nice grip and the rear has absolutely zero grip (some sort of non-friction super-ice). Also factor out drivetrain friction. Since the rears now have zero friction, it takes absolutely no power to drive them. But the diff is locked so that the rears can't just spin like crazy, they have to move at the same speed as the front. Now the engine is putting down the power and the speed the fronts are moving and accelerating determines how the whole car is accelerating, the front gets 100% of the power. And that's how the system can vary power from front to rear. In reality, due to the fact that the diff doesn't lock completely, and there is drivetrain friction on both ends, the max that can be "sent" to either end is about 80%.

The 4EAT works exactly the same way but uses sensors, and a computer to electronically vary the locking of the center diff.

On the Porsche the diff is biased to the rear. It works essentially the same way, but because it is biased to the rear and never completely locks up, it can never send all the power to the front.

C
 

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GV27, great post! Very well articulated.

It's my understanding that Subaru's mechanical, viscous coupling AWD system simply breaks down less and is more reliable than say Audi's Quattro system, which is largely electronic. Is this true, as far as you know?
 

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Well, simpler is usually better for reliability. From what I know Audi tends to be pretty inconsistent in the reliability department. Some are just totally reliable and some are lemons. Don't know why. But that's the whole car. I haven't heard anything to make me think their drivetrains are anything but reliable. On the other hand, Subaru's system is totally reliable consistently. Unless you abuse it and just break it. But again, that's the whole car.

A big difference is bucks - their comparable car as far as performance goes (S4) is $15,000 more! That's a whole Honda Civic! So they can afford to put more gadgets into it. The Subaru AWD is as effective as anything out there though. You can debate 'till you turn blue in the face about which is "better", but both systems just plain work incredibly well.
 
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