how superior is awd?
08-18-2003, 08:16 AM
#16
Race Director
Originally posted by MD951
Pikey
"But if it's so superior, then why do F1, Indy etc cars not use it? Simple...... look at the nagative aspects in the paragraph above! Road cars don't need it. "
I think the real reason is that there are rules governing how these (F1, Indy, Etc..) cars are made and allowed to race.
Pikey
"But if it's so superior, then why do F1, Indy etc cars not use it? Simple...... look at the nagative aspects in the paragraph above! Road cars don't need it. "
I think the real reason is that there are rules governing how these (F1, Indy, Etc..) cars are made and allowed to race.
In the WRC the 2WD cars are actually faster on some tarmac stages, this since the difference betwen grip on 4WD or 2WD is smaller and the 2WD's are lighter and can brake later and corner faster.
It's all about grip and weight, and 4WD's weigh more and have to brake earlier because of this. They do have more grip when starting to accelerate but then it's to late.
08-18-2003, 09:39 AM
#17
Drifting
Join Date: Jun 2001
Location: The old country
Posts: 2,605
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by MD951
I think the real reason is that there are rules governing how these (F1, Indy, Etc..) cars are made and allowed to race.
I think the real reason is that there are rules governing how these (F1, Indy, Etc..) cars are made and allowed to race.
It's probably safe to say that a AWD F1 car would be far superior in the wet, so if you have the money, why not build one, and keep the 2wd for the dry. Smaller teams wouldn't stand a chance!!!
Originally posted by sweanders
In the WRC the 2WD cars are actually faster on some tarmac stages, this since the difference betwen grip on 4WD or 2WD is smaller and the 2WD's are lighter and can brake later and corner faster.
It's all about grip and weight, and 4WD's weigh more and have to brake earlier because of this. They do have more grip when starting to accelerate but then it's to late.
In the WRC the 2WD cars are actually faster on some tarmac stages, this since the difference betwen grip on 4WD or 2WD is smaller and the 2WD's are lighter and can brake later and corner faster.
It's all about grip and weight, and 4WD's weigh more and have to brake earlier because of this. They do have more grip when starting to accelerate but then it's to late.
08-18-2003, 11:09 AM
#18
Nordschleife Master
AWD - 4wd.....
Here is one word UNDERSTEER.......
Everyone knows a 911 will understeer coming into a corner.
Make you Grab for your ***** when exiting.
Add carrara 4 the car ADD's understeer, weight and also looses all its ***** when exiting a cornor..... (aka its more controlled..)
Thats the one thing I didnt understand the only advantage on AWD in a 911 is all weather driving. The "more traction" idea is retarded for this reason. the 911 is 65% rear wheel biased? and with LSD 255's or wider rear tires. Off the line how much do you think the front wheel drive is doing? ALL THE WEIGHT IS IN THE BACK AND ALL YOUR OTHER WEIGHT HAS SHIFTED TO THE BACK. so ? why is AWD better? the traction cannot over come the disadvantage as far as weight goes. The other theory is "more control" and for that I give you this You then have no reason to even be in a 911.
BTW still the 2 fastest 911's are RWD.
Here is one word UNDERSTEER.......
Everyone knows a 911 will understeer coming into a corner.
Make you Grab for your ***** when exiting.
Add carrara 4 the car ADD's understeer, weight and also looses all its ***** when exiting a cornor..... (aka its more controlled..)
Thats the one thing I didnt understand the only advantage on AWD in a 911 is all weather driving. The "more traction" idea is retarded for this reason. the 911 is 65% rear wheel biased? and with LSD 255's or wider rear tires. Off the line how much do you think the front wheel drive is doing? ALL THE WEIGHT IS IN THE BACK AND ALL YOUR OTHER WEIGHT HAS SHIFTED TO THE BACK. so ? why is AWD better? the traction cannot over come the disadvantage as far as weight goes. The other theory is "more control" and for that I give you this You then have no reason to even be in a 911.
BTW still the 2 fastest 911's are RWD.
08-18-2003, 12:32 PM
#19
Three Wheelin'
AWD will help you go, but it won't help you stick. It's only useful for putting power down. I've never driven a 993tt, I'm sure it sticks like rails. I have driven a 993 and it sticks like rails! If you're powering out of a corner and your rear wheels are starting to spin, AWD will help you put more power down, but it won't help keep you from sliding sideways off a race track.
I'm not saying that AWD won't help you get around a dry paved track faster, but it won't help your car "handle" better if properly balanced.
As for brakes...You jam on the brakes, and immediately (in a perfect world) 100% of each tire is dedicated to stopping the car, how is AWD gonna help in that situation?
I'm not saying that AWD won't help you get around a dry paved track faster, but it won't help your car "handle" better if properly balanced.
As for brakes...You jam on the brakes, and immediately (in a perfect world) 100% of each tire is dedicated to stopping the car, how is AWD gonna help in that situation?
08-18-2003, 05:50 PM
#20
Three Wheelin'
Join Date: Apr 2003
Location: Phoenix, AZ
Posts: 1,354
Likes: 0
Received 0 Likes
on
0 Posts
People are making too many generalizations here. Not all awd cars are identical, and what helps one might hurt another.
AWD will help any car maintain/regain traction on a turn (on any surface, it just becomes more important on a loose or slick surface). When the front wheels slip under hard cornering, the best way to get them to grab again is to have them spin, and wheels under power spin better.
The downside is that it will induce understeer.
Almost everything else depends on the car in question. Comparing a 964/993/996 C2 to the matching C4, you'll see some differences.
The C4 is slower than its 2WD brother, because it weighs more but has the same engine.
The C4 does not handle better on a track. It handles worse, because of the understeer.
The C4 handles much better on a slick or loose surface.
The C4 does not have a better launch. Because of the weight bias of the 911 design, it's pointless to put power on the front wheels. The C4 is a RWD car at launch. There's a switch to engage AWD (for bad conditions), but otherwise the fronts don't kick in until the car is moving.
An Evo or WRX has a nearly opposite weight bias, so of course they benefit from putting power on the front wheels at a launch.
The Carerra GT is RWD, the GT1, 2, and 3 are RWD, the entire Ferarri line is RWD, the M3 is RWD, the entire Lotus line is RWD, the NSX is RWD, etc. On dry asphalt RWD is better. On gravel, snow, or rain AWD is superior.
AWD will help any car maintain/regain traction on a turn (on any surface, it just becomes more important on a loose or slick surface). When the front wheels slip under hard cornering, the best way to get them to grab again is to have them spin, and wheels under power spin better.
The downside is that it will induce understeer.
Almost everything else depends on the car in question. Comparing a 964/993/996 C2 to the matching C4, you'll see some differences.
The C4 is slower than its 2WD brother, because it weighs more but has the same engine.
The C4 does not handle better on a track. It handles worse, because of the understeer.
The C4 handles much better on a slick or loose surface.
The C4 does not have a better launch. Because of the weight bias of the 911 design, it's pointless to put power on the front wheels. The C4 is a RWD car at launch. There's a switch to engage AWD (for bad conditions), but otherwise the fronts don't kick in until the car is moving.
An Evo or WRX has a nearly opposite weight bias, so of course they benefit from putting power on the front wheels at a launch.
The Carerra GT is RWD, the GT1, 2, and 3 are RWD, the entire Ferarri line is RWD, the M3 is RWD, the entire Lotus line is RWD, the NSX is RWD, etc. On dry asphalt RWD is better. On gravel, snow, or rain AWD is superior.
08-18-2003, 06:30 PM
#21
Sweet god in heaven...
if opinions were worth a dollar, this would be a million dollar thread...too bad the level of tech is so low.
Opinions are like ********, everyone has one... - classic wisdom of the ages
Here is some tech, for all you opinionated fellows
http://www.toymods.org.au/fwd_rwd_awd.html (this is semi-tech)
http://www.epinions.com/content_2038145156 (better, slightly)
http://www.whiteline.com.au/faqelse0...FWD%20vs%20RWD (not bad, very little AWD tech)
if opinions were worth a dollar, this would be a million dollar thread...too bad the level of tech is so low.
Opinions are like ********, everyone has one... - classic wisdom of the ages
Here is some tech, for all you opinionated fellows
http://www.toymods.org.au/fwd_rwd_awd.html (this is semi-tech)
http://www.epinions.com/content_2038145156 (better, slightly)
http://www.whiteline.com.au/faqelse0...FWD%20vs%20RWD (not bad, very little AWD tech)
08-18-2003, 06:46 PM
#22
Racer
Thread Starter
Join Date: Dec 2002
Location: Columbus, OH.
Posts: 329
Likes: 0
Received 0 Likes
on
0 Posts
Ok so awd doesn't help you actually handle better, but it does make you corner faster. What about the quaiffe differential for our cars? does anybody have one? man, now i want some better tires bad, oh and a better differential.
02-10-2004, 11:15 PM
#23
Pro
Join Date: Mar 2003
Location: Montgomery, AL
Posts: 617
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Rich Sandor
If you can storm down the street and lock up your wheels under heavy breaking, upgrading to Big Reds or whatever else will not decrease your stopping distance or increase breaking performance. For that, all you can do is put more rubber to the road, wider tyres or slicks. What big reds and other brake upgrades DO achieve is longer pad/rotor life, and consistancy on track. So with my 86 turbo brakes, they might start fading after a dozen laps or so, and i'd ahve to start braking earlier and earlier after every lap. Whereas with big reds, they maintain thier stopping power lap after lap.
If you can storm down the street and lock up your wheels under heavy breaking, upgrading to Big Reds or whatever else will not decrease your stopping distance or increase breaking performance. For that, all you can do is put more rubber to the road, wider tyres or slicks. What big reds and other brake upgrades DO achieve is longer pad/rotor life, and consistancy on track. So with my 86 turbo brakes, they might start fading after a dozen laps or so, and i'd ahve to start braking earlier and earlier after every lap. Whereas with big reds, they maintain thier stopping power lap after lap.
More rubber on the ground WILL NOT increase braking potential. The pressure on per square inch on the ground is inversely proportional to the surface area -- as one increases the other decreases equally, so no matter how wide your tires are, you're not getting any more stopping ability. However, if you were to put wider tires on the front than rear, there'd be more pressure on them than in back and you'd stop faster, but not much since the weight transfer already makes your rear brakes more important for keeping the rear in back than helping you stop.
Sure, it's not very intuitive, but it's true. Oh, and I realized I dug up a century old thread, but it's interesting.
I obviously love AWD. Even in dry conditions (at least with my all weather tires) the front wheels help you pull out of turns. And in AWD, the 4 wheels are not "linked" as in a 4WD truck -- 4 linked wheels is 4WD. AWD always on and LSD.
AWD does result in understeer, but not too horribly, and a decent sized rear sway and solve it real quick.
02-13-2004, 10:27 PM
#24
Racer
Join Date: Feb 2004
Location: Richmond, VA.
Posts: 263
Likes: 0
Received 0 Likes
on
0 Posts
I've had experience with 2 AWD cars, my current WRX and a bunch of 1991 Isuzu Impulse RS's. It has its disadvantages (rolling starts/highway rolls are slower, drivetrain loss) but I would rather have the "peace of mind" that comes with them. That old impulse was so very quick with its AWD that many mustangs were "very" surprised by that "damn POS Geo Storm" and the WRX...well, that car speaks for itself. Give me AWD over anything else!
02-14-2004, 01:39 AM
#25
Pro
Join Date: Apr 2003
Location: The mistake on the lake other wise known as Erie PA
Posts: 749
Likes: 0
Received 0 Likes
on
0 Posts
So if there is rear wheel drive for Ideal driving condtions and all wheel drive for non ideal what is the point of front wheel drive, A happy inbetween the two? In a perfect world a car that had a AWD system with no added weight over the base car and the abilty to make it just RWD in good condtions would be the best traction/performance wise.
02-14-2004, 02:10 AM
#26
Three Wheelin'
Join Date: Sep 2003
Location: Bremerton, WA
Posts: 1,750
Likes: 0
Received 0 Likes
on
0 Posts
im confused now
a 4x4 truck only puts power to 2 wheels at a time, correct!!!
and awd puts power to all 4 tires and is able to change what amounts it puts to each tire.
a 4x4 can do the same: change from having the power at this tire to having it at that tire.
a 4x4 truck only puts power to 2 wheels at a time, correct!!!
and awd puts power to all 4 tires and is able to change what amounts it puts to each tire.
a 4x4 can do the same: change from having the power at this tire to having it at that tire.
02-14-2004, 02:14 AM
#27
Three Wheelin'
Join Date: Sep 2003
Location: Bremerton, WA
Posts: 1,750
Likes: 0
Received 0 Likes
on
0 Posts
awd and 4 wheel drive helps because it can give traction to a tire that had none before
BUT can someone explain in SIMPLE ENGLISH how it helps braking??!!??!!?!?!?! cause i just don't get it!!
BUT can someone explain in SIMPLE ENGLISH how it helps braking??!!??!!?!?!?! cause i just don't get it!!
02-14-2004, 10:02 AM
#28
Instructor
Join Date: Mar 2002
Location: Cincinnati, OH
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
Man this is a scary thread. Everyone putting in an opinion, with very little fact, and a whole lot of misinformation.
As Ag951 said, you have to analyze this based upon the type of AWD system. You can have simple open diff AWD, torsen or haldex AWD, 4wd, ect. They are all different and all have their own nuances.
My Audis all have open center and rear diffs, that are lockable. This means at all times, I have power to each wheel being distributed evenly. The downside is that when one wheel starts slipping, the system will send more power to that wheel, just like a RWD car with no LSD. The good part is, that there is less power going to each wheel, so the occurences of that are very rare. They make a HUGE difference in any sort of inclement weather.
In dry, it still makes a difference. BUT, you have to learn a different driving style than you would use in a RWD or FWD car. The grip coming out of a fast corner is amazing. Slower into the turn, but you can stomp on the gas much earlier, which makes up for the slower entry.
Audi raced AWD cars on tarmac for years, and proved how successful it can be. Oftentimes when they raced, they were required to carry extra weight in order to make up for the "unfair advantage". There is tons of great reading material out there that details Audi's involvement in racing.
As far as drivetrain losses, when studies were done by audi from it's first forays into AWD, they found that the losses were not nearly as significant as they had thought. Can't find the article I was looking at before, but it was less than 5% difference in losses I believe.
On braking, it really depends on the AWD system again, on whether it helps or not. On my cars, it doesn't help a bit in the dry, during normal operation. The weight of the AWD system is a slight disadvantage. On slick surfaces, if I have the center differential locked, it will help, as the front brakes can't lock up as easily.
With a viscous center differential (torsen style), you can get some of this effect any time the fronts lock up before the rear, whether it be on dry or in bad weather.
I believe that a proper brake bias setup on any car can negate this advantage however, especially if you have a proportioning valve that has the ability to change the bias from front to rear as needed.
Anyhow, in summation, those of you guys who have never driven an AWD car really need to spend some quality seat time in one. I'm with UDpride on the fact that I'd never buy another daily driver without it.
As Ag951 said, you have to analyze this based upon the type of AWD system. You can have simple open diff AWD, torsen or haldex AWD, 4wd, ect. They are all different and all have their own nuances.
My Audis all have open center and rear diffs, that are lockable. This means at all times, I have power to each wheel being distributed evenly. The downside is that when one wheel starts slipping, the system will send more power to that wheel, just like a RWD car with no LSD. The good part is, that there is less power going to each wheel, so the occurences of that are very rare. They make a HUGE difference in any sort of inclement weather.
In dry, it still makes a difference. BUT, you have to learn a different driving style than you would use in a RWD or FWD car. The grip coming out of a fast corner is amazing. Slower into the turn, but you can stomp on the gas much earlier, which makes up for the slower entry.
Audi raced AWD cars on tarmac for years, and proved how successful it can be. Oftentimes when they raced, they were required to carry extra weight in order to make up for the "unfair advantage". There is tons of great reading material out there that details Audi's involvement in racing.
As far as drivetrain losses, when studies were done by audi from it's first forays into AWD, they found that the losses were not nearly as significant as they had thought. Can't find the article I was looking at before, but it was less than 5% difference in losses I believe.
On braking, it really depends on the AWD system again, on whether it helps or not. On my cars, it doesn't help a bit in the dry, during normal operation. The weight of the AWD system is a slight disadvantage. On slick surfaces, if I have the center differential locked, it will help, as the front brakes can't lock up as easily.
With a viscous center differential (torsen style), you can get some of this effect any time the fronts lock up before the rear, whether it be on dry or in bad weather.
I believe that a proper brake bias setup on any car can negate this advantage however, especially if you have a proportioning valve that has the ability to change the bias from front to rear as needed.
Anyhow, in summation, those of you guys who have never driven an AWD car really need to spend some quality seat time in one. I'm with UDpride on the fact that I'd never buy another daily driver without it.
02-15-2004, 08:40 PM
#29
Instructor
Join Date: Jan 2004
Location: UK
Posts: 133
Likes: 0
Received 0 Likes
on
0 Posts
Cat amongst the pigeons time..... Sorry to come in late but I had to vent my opinions..... I’m with Greg.
My Ur Quattro handled better than my 944, but the 944 can go round corners faster. My definition of 'handling' is the cars ability to change direction predictably under all conditions, it has nothing to do with grip (the 944 grips better, sideways at least). Handling is also the ability and reliability that the car has to recover from a break in traction.
I changed because I wanted to learn to drive competently. ANYONE can get into an AWD car and drive quickly; they sort out your mistakes and are much more predictable. I've read the dreaded word "understeer" in this thread. Low speed understeer is a fact of life with any AWD or FWD car, but how many of us have experienced understeer in our 944's, 924's and 968's. All, I would bet.
The Quattro is especially nose heavy, but you would be surprised at how that low speed understeer changed to nicely neutral at speed and oversteer at the limit. But this forum isn't about Audis......
The great thing about AWD is that the drive train is locked (within reason) between all four wheels. This means that it DOES help braking as braking force is distributed evenly between all four tires. I read here that if your braking is set up correctly on a RWD car, the advantage of AWD is negligible or non-existent. What about braking over bumps or round corners??? (I'm gonna have the purists saying that 'you should never brake while cornering' - this is my point) The braking bias is controlled by the rear suspension, if you have bumps during your braking zone then your rear brakes cannot work effectively (I'm talking pre-ABS).
So why am I an avid 944 fan and why didn't I keep the Quattro. Easy, the 944 is so responsive to any driver input. Change the throttle mid corner and you can instantly feel the change in the poise of the car. Spend more time adjusting braking points and the line that you take through bends and you are rewarded with a sublime feeling of achievement. In an AWD car, to exit a junction you turn the wheel and floor it. No fuss, no drama. In a properly sorted RWD you have to think. The Porsche has the capability to be faster, but you have to be a much better driver to extract the performance.
AWD is all things to all people and for most it IS the most reliable, safest solution. It's NOT a gimmick for road cars, and most of us could drive faster in ALL conditions if our 9XX's had AWD. Seriously.
However, the 1% who can tame RWD like the professionals do, will effortlessly glide past us on race day, even if they have half the horsepower. You'll never learn how to drive like that in a car that corrects your every mistake.
AWD IS that good, a better driver with RWD is still better.
My Ur Quattro handled better than my 944, but the 944 can go round corners faster. My definition of 'handling' is the cars ability to change direction predictably under all conditions, it has nothing to do with grip (the 944 grips better, sideways at least). Handling is also the ability and reliability that the car has to recover from a break in traction.
I changed because I wanted to learn to drive competently. ANYONE can get into an AWD car and drive quickly; they sort out your mistakes and are much more predictable. I've read the dreaded word "understeer" in this thread. Low speed understeer is a fact of life with any AWD or FWD car, but how many of us have experienced understeer in our 944's, 924's and 968's. All, I would bet.
The Quattro is especially nose heavy, but you would be surprised at how that low speed understeer changed to nicely neutral at speed and oversteer at the limit. But this forum isn't about Audis......
The great thing about AWD is that the drive train is locked (within reason) between all four wheels. This means that it DOES help braking as braking force is distributed evenly between all four tires. I read here that if your braking is set up correctly on a RWD car, the advantage of AWD is negligible or non-existent. What about braking over bumps or round corners??? (I'm gonna have the purists saying that 'you should never brake while cornering' - this is my point) The braking bias is controlled by the rear suspension, if you have bumps during your braking zone then your rear brakes cannot work effectively (I'm talking pre-ABS).
So why am I an avid 944 fan and why didn't I keep the Quattro. Easy, the 944 is so responsive to any driver input. Change the throttle mid corner and you can instantly feel the change in the poise of the car. Spend more time adjusting braking points and the line that you take through bends and you are rewarded with a sublime feeling of achievement. In an AWD car, to exit a junction you turn the wheel and floor it. No fuss, no drama. In a properly sorted RWD you have to think. The Porsche has the capability to be faster, but you have to be a much better driver to extract the performance.
AWD is all things to all people and for most it IS the most reliable, safest solution. It's NOT a gimmick for road cars, and most of us could drive faster in ALL conditions if our 9XX's had AWD. Seriously.
However, the 1% who can tame RWD like the professionals do, will effortlessly glide past us on race day, even if they have half the horsepower. You'll never learn how to drive like that in a car that corrects your every mistake.
AWD IS that good, a better driver with RWD is still better.
