RWD vs AWD

[LarThaL]

So I am going to start this discussion from a tangent of sorts. The automobile was originally invented for the sole purpose of facilitating transportation. It soon became apparent, however, that a significant amount of sensory enjoyment came along with this endeavor. And so the enjoyment of driving was born, along with the car enthusiast, racing, etc. The rest is history.

At the two ends of the modern automotive spectrum, one could argue that you have the formula one race car vs. the Minivan. Pure performance thrill machine vs. Pure transport tool.

Everything else falls somewhere in between. RWD has traditionally been recognized as the superior configuration for objective and subjective driving dynamics. The principle is simple: push from the back, steer from the front. Each axle has a single function and can thus perform those functions better. The result is a car that gives you better steering feel and responsiveness, and that is more lively and fun.

However, as one tries to make a car more and more practical, does preaching the RWD mantra in order to try and preserve a certain driving dynamic make sense? Furthermore, when you then try to make these practical cars more and more powerful, especially with torque laden turbo motors, does it still make sense to continue with RWD.

I am bringing this up because I am trying to make the point that cars like the F80 M3/4 and F10/12 M5/6 have no business being RWD.

A RWD car is best suited to the power delivery of a NA or maybe SC motor. The torque delivery needs be moderate and come later in the rev range. The traction is not overwhelmed, and the car can benefit from the RWD configuration’s superior driving dynamics. If you are going to put a turbo motor in a RWD car, it is best suited in a mid-engine design with really fat rubber. Again, you need to match the power delivery with the traction capability.

The latest M3-6 are totally mismatched. Big, early torque with the weight of the engine in front, and the drive at the rear with relatively narrow tires. I contend that the 5/6 need at least 325s or more to get the power down and even then, it will be a struggle. The M3/4 should have 305s from the factory. In the end, with their current size, layout, purpose and engine configuration, they need AWD.

So what is the perfect RWD car? The Porsche Cayman. Mid-engine, moderate power, NA. Perfectly suited to exploit the driving dynamics that RWD will give you. However, it is a 2-seater with limited practicality.

Bottom line….if you want a big, high-torque people hauler, forget about trying to hold on to some theoretical benefit of RWD. The car is too compromised in its overall intent and design to take advantage of it. Make it AWD and let it put the power down. Save RWD for tire shredding gimmicky muscle cars, and cars whose overall design can really properly take advantage of the RWD platform. From that standpoint, I think the e9x platform is simply phenomenal in terms of combining practicality, at the limits of RWD dynamic usability.

[Ezio]

I was reading on the GTR forums yesterday of a guy who had a M4 and wanted to move into a GTR. The GTR guys were even saying how the M4 is not suited for RWD.

I think if car companies keep making these turbo engines, they are going to move to AWD sooner or later.

[Billj747]

BMW could easily size their turbos to have the tq peak later in the rpm band and not choke at high rpm. However this would result in a power band thats more like the s65 v8 which has significantly less response and tq at lower rpms, which makes it feel slow for the majority of daily driving.

At the end of the day, if you have the grip to put down power with RWD, AWD isn't advantageous. For a higher speed racetrack where grip is not a concern, RWD would probably be better, same for a car with turbo sized accordingly Where the power band does not overwhelm the tires. Now for a tight, low speed track with a lot of power and less trippy tires, AWD will have significant advantages.

I'm not sure I would agree that an M4/3 need to be AWD, the car will become much heavier from an AWD system and that could outweigh it's benefits. On street tires, AWD may have more advantages but a better set of tires could eliminate this advantage.

[clar]

LarThaL, I am with u on this! The FR layout of M cars make huge low end torque a curse rather than a blessing. There is a reason why Ferrari tuned the torque delivery of the Cali T to be like NA. Apart from encouraging people to rev the car, it also makes harnessing power from the engine more productive and efficient. No sense having the wheels break loose only to be reigned in by the traction control and messing up the whole experience. The current crop of turbo M cars are nothing more than a stop-gap measure until the next round of proper drive trains take over. Something along the lines of NSX should be common place for next generation cars. Batteries are improving, though could have been faster, but it's nevertheless getting closer to being a viable alternative. Turbo charging at the rear wheels + eletric motors at the front wheels should be a blast.

[STALKER]

I don't agree that a car should be this or that.
My issue is with the general sort of ppl buying these cars. They have no experience, training and respect for the power.

You want a high horsepower car, get some driver training to go along with it.

[clar]

Originally Posted by STALKER

I don't agree that a car should be this or that.
My issue is with the general sort of ppl buying these cars. They have no experience, training and respect for the power.

You want a high horsepower car, get some driver training to go along with it.

It's unrealistic to expect everybody to go for driver training b4 buying these cars. Even with driver training, it's easy to get caught out by huge surge of low end torque. FR layout has its limits and due to competition, car makers are forced to put in ever more power/torque into the cars. This itself is a bigger problem. How often do we get to use those power?

[STALKER]

Originally Posted by clar

It's unrealistic to expect everybody to go for driver training b4 buying these cars. Even with driver training, it's easy to get caught out by huge surge of low end torque. FR layout has its limits and due to competition, car makers are forced to put in ever more power/torque into the cars. This itself is a bigger problem. How often do we get to use those power?

You also learn to respect a car, its power, its limitations and your own limitations with proper driving training.

[FTS]

Originally Posted by LarThaL

I am bringing this up because I am trying to make the point that cars like the F80 M3/4 and F10/12 M5/6 have no business being RWD.

All that 4WD/AWD does is split the torque across axles or individual wheels, so you get less power going to each corner of the car. Traction is created by the tires at the end of the day, so with proper tires you can channel much higher torque/power than M3/4 or M5/6 have to the ground (there are many methods to improve traction beyond tires of course if one feels there isn't enough of it, which I think there more than enough in the F8x). For example, McLaren, Porsche GT2, Ferrari F40/50/60/FF/F12, etc. Have you seen a 4WD top fuel dragster? They run 1/4 from standing start in less than 3.9 secs with only RWD and have ~10,000 hp; all about tires!

I am assuming, correct me if I am wrong, that an F8x is faster than an RS4/5/7 to the quarter mile or full mile, or on any given race circuit, right? If this assumption is right, then you should not assume there isn't enough traction in the F8x, and if correct, then there is only a mismatch in your head.

Originally Posted by clar

It's unrealistic to expect everybody to go for driver training b4 buying these cars. Even with driver training, it's easy to get caught out by huge surge of low end torque.

I somewhat disagree with you. I believe, maybe wrongly, that the M cars are designed for the customer that enjoys driving cars and takes driving seriously to become better at it, although there are many exceptions I am sure. I wouldn't expect for any of today's cars to be driven to their limit without proper and continuous training. I think there are enough posts around all cars that show what happens when someone tries to explore the limits without such training.

Also, I have to state that I know only few groups of people that take such training, be it autox or track, but even much smaller number of people who actually make an attempt to learn how to drive 4WD cars. Just because a car is 4WD does not automatically mean better traction, most don't know how to use a 4WD car IMO, 4WD is only useful under power and because power is split between axles and wheels, more power than FWD or RWD cars, hence more throttle. How many drive around on the streets with their throttle on majority of the time even in corners?

[Ezio]

Originally Posted by clar

It's unrealistic to expect everybody to go for driver training b4 buying these cars. Even with driver training, it's easy to get caught out by huge surge of low end torque. FR layout has its limits and due to competition, car makers are forced to put in ever more power/torque into the cars. This itself is a bigger problem. How often do we get to use those power?

It really bugs me when people use the "when will you use that power" , or "thats more than enough power for the streets".

Even when we are not using the power 95% of the time, its the idea that its there. Also its very fun to have lots of power on the streets, it may get very illegal at times. But there is a time and place for it.

I am not saying cars need 800HP+ either, there is a point where there is to much power. the M3 is far from that point.

[clar]

Top fuel dragsters are not front engined and the size of their tires are out of this world. My beef is with mixing low end torque and FR layout. I have never owned an AWD car before and have no intention to buy one anytime soon. My issue is with the way things are going at the moment. Huge low end torque with limited traction is not a lot of fun. There are times when u want to get away quickly either from a dig or on the move and give it the beans. I am sure these moments happen to us all whether u have driver training or not. Do that on a car like the current M3/4 or M5 and u know what happens. I have toyed with the idea of getting sticker tires as wider tires don't help with traction. Wanna know how much a set of Michelin Cup 2 tires cost vs PSS? Huge low end torque + FR layout = trouble.

Originally Posted by FTS

All that 4WD/AWD does is split the torque across axles or individual wheels, so you get less power going to each corner of the car. Traction is created by the tires at the end of the day, so with proper tires you can channel much higher torque/power than M3/4 or M5/6 have to the ground (there are many methods to improve traction beyond tires of course if one feels there isn't enough of it, which I think there more than enough in the F8x). For example, McLaren, Porsche GT2, Ferrari F40/50/60/FF/F12, etc. Have you seen a 4WD top fuel dragster? They run 1/4 from standing start in less than 3.9 secs with only RWD and have ~10,000 hp; all about tires!

I am assuming, correct me if I am wrong, that an F8x is faster than an RS4/5/7 to the quarter mile or full mile, or on any given race circuit, right? If this assumption is right, then you should not assume there isn't enough traction in the F8x, and if correct, then there is only a mismatch in your head.


I somewhat disagree with you. I believe, maybe wrongly, that the M cars are designed for the customer that enjoys driving cars and takes driving seriously to become better at it, although there are many exceptions I am sure. I wouldn't expect for any of today's cars to be driven to their limit without proper and continuous training. I think there are enough posts around all cars that show what happens when someone tries to explore the limits without such training.

Also, I have to state that I know only few groups of people that take such training, be it autox or track, but even much smaller number of people who actually make an attempt to learn how to drive 4WD cars. Just because a car is 4WD does not automatically mean better traction, most don't know how to use a 4WD car IMO, 4WD is only useful under power and because power is split between axles and wheels, more power than FWD or RWD cars, hence more throttle. How many drive around on the streets with their throttle on majority of the time even in corners?

[s85e90]

Originally Posted by LarThaL

So I am going to start this discussion from a tangent of sorts. The automobile was originally invented for the sole purpose of facilitating transportation. It soon became apparent, however, that a significant amount of sensory enjoyment came along with this endeavor. And so the enjoyment of driving was born, along with the car enthusiast, racing, etc. The rest is history.

At the two ends of the modern automotive spectrum, one could argue that you have the formula one race car vs. the Minivan. Pure performance thrill machine vs. Pure transport tool.

Everything else falls somewhere in between. RWD has traditionally been recognized as the superior configuration for objective and subjective driving dynamics. The principle is simple: push from the back, steer from the front. Each axle has a single function and can thus perform those functions better. The result is a car that gives you better steering feel and responsiveness, and that is more lively and fun.

However, as one tries to make a car more and more practical, does preaching the RWD mantra in order to try and preserve a certain driving dynamic make sense? Furthermore, when you then try to make these practical cars more and more powerful, especially with torque laden turbo motors, does it still make sense to continue with RWD.

I am bringing this up because I am trying to make the point that cars like the F80 M3/4 and F10/12 M5/6 have no business being RWD.

A RWD car is best suited to the power delivery of a NA or maybe SC motor. The torque delivery needs be moderate and come later in the rev range. The traction is not overwhelmed, and the car can benefit from the RWD configuration’s superior driving dynamics. If you are going to put a turbo motor in a RWD car, it is best suited in a mid-engine design with really fat rubber. Again, you need to match the power delivery with the traction capability.

The latest M3-6 are totally mismatched. Big, early torque with the weight of the engine in front, and the drive at the rear with relatively narrow tires. I contend that the 5/6 need at least 325s or more to get the power down and even then, it will be a struggle. The M3/4 should have 305s from the factory. In the end, with their current size, layout, purpose and engine configuration, they need AWD.

So what is the perfect RWD car? The Porsche Cayman. Mid-engine, moderate power, NA. Perfectly suited to exploit the driving dynamics that RWD will give you. However, it is a 2-seater with limited practicality.

Bottom line….if you want a big, high-torque people hauler, forget about trying to hold on to some theoretical benefit of RWD. The car is too compromised in its overall intent and design to take advantage of it. Make it AWD and let it put the power down. Save RWD for tire shredding gimmicky muscle cars, and cars whose overall design can really properly take advantage of the RWD platform. From that standpoint, I think the e9x platform is simply phenomenal in terms of combining practicality, at the limits of RWD dynamic usability.

All of your posts center around big HP needing AWD almost certainly.. This is soo wrong, and plenty of BIG HP cars are RWD only.

Think z06, 911 gt2..

Just some food for thought, many people remove the front diff and disable the 911 turbo AWD setup in favor of a RWD setup. Both setups have their advantages, but it's more than traction. With the front wheels being driven, the steering radius suffers, steering feels numb from having axles anda diff, etc. I personally know of plenty of very high HP RWD only cars that work just fine. Learning to drive these cars is the key, not immediately saying they need AWD.

[s85e90]

Probaly #1 gripe of M owners all over is wanting more TQ. BMW delivers and now everyone complains. This board is a joke.

[LarThaL]

Originally Posted by s85e90

All of your posts center around big HP needing AWD almost certainly.. This is soo wrong, and plenty of BIG HP cars are RWD only.

Think z06, 911 gt2..

Just some food for thought, many people remove the front diff and disable the 911 turbo AWD setup in favor of a RWD setup. Both setups have their advantages, but it's more than traction. With the front wheels being driven, the steering radius suffers, steering feels numb from having axles anda diff, etc. I personally know of plenty of very high HP RWD only cars that work just fine. Learning to drive these cars is the key, not immediately saying they need AWD.

Big HP doesn't necessarily need AWD. Big, early TORQUE in an upright, people hauling, front engine car needs AWD. Look at some of clar's comments also. Hits nail on head.

Originally Posted by s85e90

Probaly #1 gripe of M owners all over is wanting more TQ. BMW delivers and now everyone complains. This board is a joke.

People aren't thinking about the whole package. Yes, more torque is nice if you have the traction to manage it. Again, we are not talking about pure sports cars or even muscle cars which need a certain amount of tire shredding capability to fulfill their intended purpose. We are talking about 4/5-seaters with practical transport capabilities. Cars that will always be primarily street driven.

The engine characteristics that most people are looking for, I think, can only really be had with a larger displacement NA motor. That's why I am really eager to see how a car like the Mustang GT350 plays out, however even that may not be a valid comparison as this is a more track focused muscle car.

I would have loved to see the M3/4 with a 5-liter 500hp V8 with 400lb-ft of NA torque, RWD, and 275/315 tires.

[pbonsalb]

Originally Posted by FTS

All that 4WD/AWD does is split the torque across axles or individual wheels, so you get less power going to each corner of the car. Traction is created by the tires at the end of the day, so with proper tires you can channel much higher torque/power than M3/4 or M5/6 have to the ground (there are many methods to improve traction beyond tires of course if one feels there isn't enough of it, which I think there more than enough in the F8x). For example, McLaren, Porsche GT2, Ferrari F40/50/60/FF/F12, etc. Have you seen a 4WD top fuel dragster? They run 1/4 from standing start in less than 3.9 secs with only RWD and have ~10,000 hp; all about tires!

I am assuming, correct me if I am wrong, that an F8x is faster than an RS4/5/7 to the quarter mile or full mile, or on any given race circuit, right? If this assumption is right, then you should not assume there isn't enough traction in the F8x, and if correct, then there is only a mismatch in your head.

?

RS7 is very fast. Probably quicker than an M3. Definitely quicker most of the time in the real world where traction is an issue. Yes, drag radials will allow a high powered rwd car to hook up, but they suck in handling, rain and cold.

[W///]

Originally Posted by Ezio

It really bugs me when people use the "when will you use that power" , or "thats more than enough power for the streets".

Even when we are not using the power 95% of the time, its the idea that its there. Also its very fun to have lots of power on the streets, it may get very illegal at times. But there is a time and place for it.

I am not saying cars need 800HP+ either, there is a point where there is to much power. the M3 is far from that point.

Great, but that's not what everyone wants. While I enjoy the power as much as the next guy on the street, I also really enjoy mountain driving. We've got some absolutely amazing roads here in NC and SC. I can tell you right now I have 0 interest (really mean it) in taking a Z06 up there. My E36 with 240 hp is an absolute blast up in the mountains because you can actually use the car.

Don't understand why that bugs you. If that was the case, absolutely no one would buy a GT4 and go for a Z06 instead, but that's obviously not the case. For what it's worth, I'd get the GT4 over the Z06 every single day of the week.

[FTS]

Originally Posted by clar

Top fuel dragsters are not front engined and the size of their tires are out of this world. My beef is with mixing low end torque and FR layout. I have never owned an AWD car before and have no intention to buy one anytime soon. My issue is with the way things are going at the moment. Huge low end torque with limited traction is not a lot of fun. There are times when u want to get away quickly either from a dig or on the move and give it the beans. I am sure these moments happen to us all whether u have driver training or not. Do that on a car like the current M3/4 or M5 and u know what happens. I have toyed with the idea of getting sticker tires as wider tires don't help with traction. Wanna know how much a set of Michelin Cup 2 tires cost vs PSS? Huge low end torque + FR layout = trouble.

There are advantages to mid-engine from a weight distribution point of view, and even more advantages for rear-engine layout; however, there are also disadvantages. I am not a BMW fan, this is my first M car, I am just testing the waters in a way. My beef is because someone does not like the method or way the torque is delivered, they declare that the car is not suitable without AWD or there shouldn't have been created without any empirical data or engineering behind the statement.

If the car can do 4.1 sec 0-60 and 12 sec 1/4 mile, what is it that you are trying to achieve that needs more traction? Those are 997.2 GT3 numbers. So, there is enough traction for the performance the engine can generate. How much more traction or more weight in the rear is adequate to achieve what?

You state "There are times when u want to get away quickly either from a dig or on the move and give it the beans"; I can relate to it, but it is just a matter of managing the weight available as a driver. If you give me a superbike, I am sure I can ride it for few dozen yards without falling, but if I try to use it to get away from a stand still rapidly, I'd fall that instant on my head, that's not the bike fault, is it? It is a matter of learning how to ride a superbike properly.

If you are a kart racer you should know that it is all about weight management as a driver, because that's what yields the best traction. You wouldn't expect anyone to get into a kart and be as fast as a regular kart driver, would you?

If you don't like the F8x, fine, but don't declare it that it is not a proper car because it is lacking traction or needs AWD, especially without backing it up with engineering data. Everything is a compromise, you make your own choices, and no car is perfect.

[s85e90]

Originally Posted by W///

Great, but that's not what everyone wants. While I enjoy the power as much as the next guy on the street, I also really enjoy mountain driving. We've got some absolutely amazing roads here in NC and SC. I can tell you right now I have 0 interest (really mean it) in taking a Z06 up there. My E36 with 240 hp is an absolute blast up in the mountains because you can actually use the car.

Don't understand why that bugs you. If that was the case, absolutely no one would buy a GT4 and go for a Z06 instead, but that's obviously not the case. For what it's worth, I'd get the GT4 over the Z06 every single day of the week.

From the same standpoint a Civic Si is just as fun as you can really wring it out whereas the z06 you can't really on public roads. I don't know if I would dismiss it that quick though. More power is always better! Shit, I'm looking for a 700 whp daily.

[W///]

Originally Posted by s85e90

From the same standpoint a Civic Si is just as fun as you can really wring it out whereas the z06 you can't really on public roads. I don't know if I would dismiss it that quick though. More power is always better! Shit, I'm looking for a 700 whp daily.

And I wouldn't disagree with that. Bet you that Civic Si would be a blast up there. These roads by the Blue Ridge Parkway, you can hardly use that kind of power. And should you get it wrong, you will pinball your way down as they are narrow roads with mountains one side and guardrails on the other. Other cars I'd love to try up there would be a MINI JCW and Honda S2k.

I know a lot of people will want the power, but there's something so satisfying about throwing a car with not that much power into a corner and then actually being able to floor it on the way out without the car biting back (and without doing stupid speeds).

[Billj747]

Originally Posted by clar

Top fuel dragsters are not front engined and the size of their tires are out of this world. My beef is with mixing low end torque and FR layout. I have never owned an AWD car before and have no intention to buy one anytime soon. My issue is with the way things are going at the moment. Huge low end torque with limited traction is not a lot of fun. There are times when u want to get away quickly either from a dig or on the move and give it the beans. I am sure these moments happen to us all whether u have driver training or not. Do that on a car like the current M3/4 or M5 and u know what happens. I have toyed with the idea of getting sticker tires as wider tires don't help with traction. Wanna know how much a set of Michelin Cup 2 tires cost vs PSS? Huge low end torque + FR layout = trouble.

The Vipers, Z06s and supercharged Mustangs must be terrible cars if a 3L M3/4 has too much low end tq.

While Vipers and Z06s have very wide tires, many supercharged 5.0 Mustangs from Roush or Ford Racing or VMP, or Shelby's GT500 are putting down over 500lbft of tq to the tires pretty much off idle, through skinny 275 tires; and there are ALOT of these Mustangs out there. Having driven many of the above, IMO the M3/4 is hardly "trouble" with their powerband or tq level and the ///M guys probably sold out and gave in to the trend of powesliding perfection and setting the car up to do so because thats what sells cars these daya rather than tuning the suspension to put power down coming off corners, which sacrifices the smooth break-away and ease of drifting.

0.02

[gatorfast]

Powerful cars needing AWD, never heard those sentiments from the OP before...

But yea im sure it makes the power more "usable" to the average person. Good thing there are plenty of RWD and AWD cars to choose from so everyone can find something they like.

[Ezio]

Originally Posted by W///

Great, but that's not what everyone wants. While I enjoy the power as much as the next guy on the street, I also really enjoy mountain driving. We've got some absolutely amazing roads here in NC and SC. I can tell you right now I have 0 interest (really mean it) in taking a Z06 up there. My E36 with 240 hp is an absolute blast up in the mountains because you can actually use the car.

Don't understand why that bugs you. If that was the case, absolutely no one would buy a GT4 and go for a Z06 instead, but that's obviously not the case. For what it's worth, I'd get the GT4 over the Z06 every single day of the week.

it bugs me because if car makers made the power reasonable for the road we would all be driving car with the same power. i don't understand why people don't understand this. If the market was filled with people only like your self, cars like the Z06, bugatti, 911 turbo etc would not be made. because they wont be able to sell them.

I like the fact you can buy a GT4 AND buy a monster like the Z. I can respect both in that sense. I totally agree i think the Z06 is overkill, its to much of a monster for me to daily drive. But if i was very wealthy i would have in my collection.

and to be honest, i am open to AWD cars.

[LarThaL]

Originally Posted by Billj747

The Vipers, Z06s and supercharged Mustangs must be terrible cars if a 3L M3/4 has too much low end tq.

While Vipers and Z06s have very wide tires, many supercharged 5.0 Mustangs from Roush or Ford Racing or VMP, or Shelby's GT500 are putting down over 500lbft of tq to the tires pretty much off idle, through skinny 275 tires; and there are ALOT of these Mustangs out there. Having driven many of the above, IMO the M3/4 is hardly "trouble" with their powerband or tq level and the ///M guys probably sold out and gave in to the trend of powesliding perfection and setting the car up to do so because thats what sells cars these daya rather than tuning the suspension to put power down coming off corners, which sacrifices the smooth break-away and ease of drifting.

0.02

The Viper, ZO6, and performance Mustangs are NA or supercharged. Hence they have a much more progressive delivery of torque. These are also pure sports and muscle cars with a different intended purpose. Your comment about seriously wide tires on the Vette and Viper are also not insignificant. It makes a big difference. Look at the previous gen Z06 with 500lb-ft of NA delivered torque and a weight of like 3200lbs and it came with 275/325 (or something thereabouts). Now you have a 4300lb upright M5 with turbo delivered torque to 295s.

The M3-6 are actually luxury-performance people haulers. Their current engine characteristics in this type and size of vehicle is better suited for AWD. When shopping for my DD, I test drove an M5 and found that while the steering was definitely better than my S6, the S6 could just so effortlessly put the power down. Even with all the stability stuff off and a tune that gives me 580lb-ft, I can simply hammer the car and it will grip and go, even around corners.