Cars - Bad Design?

[Player0]

I was driving in my car today, and I started thinking about just how badly cars seem to be designed. I've been trying to learn more about cars for the past few years, and especially in the past 6 months or so since I've boughten a new car and have been fixing it up and upgrading and stuff. Not that watching Trucks on TNN constitutes me knowing anything, and I'm a novice at best on this subject.

But the basic design of modern automobiles seems quite silly. Watching movies like Tucker, or even Fight Club, you have to start wondering just what kind of big business consipiracies are going on behind the scenes. Why is it that there havent been any radical changes in automobile design since the 1930s? Are the automotive manufacteres really forcing us consumers to buy the same thing over and over again. Or are we demanding that they provide us with the same thing over and over?

Take a transmission. A very complicated piece of equipment. Especially an automatic. But at the same time, it seems so limited. I mean, 5 gears to run the whole spectrum between 1mph and 80mph? Heck, my mountain bike has 24 gears just to get up to 20mph. More gears makes a much more efficient car. On the highway, my Honda runs at about 3000-3500 RPM. Since the car is already moving 70mph, it hardly needs any engine output at all, just enough to counter any wind resistance and wheel friction. Oh, and gravity issues. Heck, the engine should be running just above idle, maybe 1000RPM at most to handle this. Now, many rigs have two gear boxes for 15-25 gears. But why don't cars? Cost? Space issues?

The drivetrain itself is pretty crappy. In an automatic transmission, you have the torque converter, which is really a pretty ingenious peice of hardware. But it robs power and torque because you can't get a complete power lock from the engine to the wheels like you can with a clutch (yes, you can lock up some torque converters). A clutch is a bad design because they burn out due to friction and slipping. WIth a manual transmission, you do have to spend a certain amount of time driving the car in a 'slipping' position. Thats terrible. Why not just connect a torque converter to a clutch system, and have a computer control the whole shifting/clutching procedure automatically. Forget mechanical automatic shifting because it works like crap most of the time. Develop a liquid clutch of sorts. Use the torque converter action in between gears, and let the computer lock the clutch plates solid when it can. Or something like that. Needless to say, there are better solutions, and I know that there are more modern designs in some of the more expensive automobiles or concept cars. But, this technology has been around for decades...why is it just starting to come out now?

An automotive break system just seems scary when you think that just one leaky hose makes the whole car stop stopping. I've experienced this first hand, and luckily I wasn't going that fast. The fact that all 4 wheels work off the same hydraulic pressure is just insane. At least use some sort of pressure balancing valve to allow the other 2 or 3 wheels to continue to break if there is a leak somewhere else. Better yet, I've seen breaking by wire with electronics. That seems like the best way to do this, although many people will complain about the feel of the breaks. Is this why it hasn't been instituted yet?

An even more radical idea is DONT throttle the engine. Engines have two peak points. At one certain RPM, they create the most power. At another certain RPM, they run the most efficiently. So an engine should only ever be run at one of those RPM ranges. Yet, in every car I've ever seen, pushing the bettle throttles the engine. Most of the time, you are not running the engine at it's best performance mode. More money for the oil companies. Are you telling me that in this day and age there is no way to run the engine at a constant RPM and have the speed of the car adjusted in other ways, either by a smart transmission, or a torque converter that slips enough to optain the proper MPH desired? Of course, there are the new hybrid cars which work kind of on this idea. Use a smaller engine running at its peak efficiency to charge batteries and run the electric motors. Im sure theres a way to do this without having to resort to electronics as well.

I'm almost sure its possible to create a car these days that gets 10x the fuel efficiency than our current cars using the same gasoline products. Is poltics holding back progress? I dont know. I just wonder what happened to innovation. I guess big business kills that.

[spldart]

Take it from an old Hot Rodder who has done some hobby tinkering with maximizing fuel economy and debunking 100mpg claims...
Stick to computers... :P

[Cabal]

ya but if did the things you suggest, i feel it would take the fun and excitement outta driving :P

I used to wonder why it took manufactures almost 40 years to make fuel injection a standard in cars. Then i got a fiat spyder with injection.... it has a carb now :D

[Synthohol]

Peugeot had a car with a progressive gearbox with conical gears in it.
the main shaft inside would ride an ice cream cone shaped gear inside so the rpms would remain consistantly at say 2000 and the car would just go progressively faster. ofcourse the power sucked because strong engines have power curves to them and cant be used on this type of trans, the power curve is limited by the engines rpms.

[spldart]

Do you have a link to that puegot tranny? I looked all over for it and came up empty handed :(

[Synthohol]

this f1 gearbox is similar but im still looking, it was about 16-18 years ago i read about it
trans f1 (http://www.cbg.ie/news/intnews-26-03-02.html)

[Tweaked!]

Actually Volkswagon was one that did have what was known as a automatic manual transmition, that didn't have a clutch. When the car was at a stndstill, the transmition automatically applied the clutch, and in between changing gears, all you had to do was let off the gas, switch gears, and go. There was even a few motorcycles in the past that had this technology. I remember having an old honda 80 dirt bike that was automatic. you just put it in gear, go, let off the gas and change the gears to the next and give it gas again. It wasn't bad, but took a lot of the fun out of the dirt bike. But of course I was only like 10 years old when I had it, so I didn't mind then ;)

[Player0]

So you guys feel that its the consumers driving the auto manufacturers to build the same car over and over again. I mean sure, there have been some exceptions to the rules, where they let the designers do something wacky with the transmission. But thats just my point! Why was it abandoned? Surely with some development it could have worked much better than what we have now?

Synth, thats exactly my point though. Look at the power curve for any engine. There is an RPM range where the horse power peaks. There is also a point on that RPM range where the engine is running at the most economy.

Now what if you always ran that engine at it's power peak of say 2800RPM and controlled the speed of the wheels through another method via transmission. If you have a transmission system that isnt loosing all that power (and its tricky i know, but computers can do it), then that engine would be much much more powerful than the same engine if you are throttling it. When you throttle an engine, you are running it at peak performance for only a fraction of a second. The rest of the time is spent making the engine spin up, and running an average HP of less than the engine can actually produce.

Instead of your standard horse power curve that hits 220HP at some peak...the horse power is a straight horizontal line on that graph always showing 220HP, dependign on how good the transmission can deal with that.

Im just saying that the most efficient way to run an engine is at 3 speeds. Idle, Economy, and Power. Let a computer control which RPMs it chooses to run the engine at, depending on the situation, and let the gearing handle spinning the wheels up.

Fuel injection and engine design is a whole other piece to the puzzle. Engines are hideous inneficient in themselves. I really have to wonder why Rotary engines didn't take off in cars.

[foment]

the rotary engine hehe....i think mazda still makes cars that use it.

what i have to wonder is why no car that uses a stirling engine...think about it....very efficient heat recovery.

i hear ginger, aka segway, might one day get a stirling engine.

[spldart]

Originally posted by Player0
Take a transmission. A very complicated piece of equipment. Especially an automatic. But at the same time, it seems so limited. I mean, 5 gears to run the whole spectrum between 1mph and 80mph? Heck, my mountain bike has 24 gears just to get up to 20mph. More gears makes a much more efficient car. On the highway, my Honda runs at about 3000-3500 RPM. Since the car is already moving 70mph, it hardly needs any engine output at all, just enough to counter any wind resistance and wheel friction. Oh, and gravity issues. Heck, the engine should be running just above idle, maybe 1000RPM at most to handle this. Now, many rigs have two gear boxes for 15-25 gears. But why don't cars? Cost? Space issues?

The drivetrain itself is pretty crappy. In an automatic transmission, you have the torque converter, which is really a pretty ingenious peice of hardware. But it robs power and torque because you can't get a complete power lock from the engine to the wheels like you can with a clutch (yes, you can lock up some torque converters). A clutch is a bad design because they burn out due to friction and slipping. WIth a manual transmission, you do have to spend a certain amount of time driving the car in a 'slipping' position. Thats terrible. Why not just connect a torque converter to a clutch system, and have a computer control the whole shifting/clutching procedure automatically. Forget mechanical automatic shifting because it works like crap most of the time. Develop a liquid clutch of sorts. Use the torque converter action in between gears, and let the computer lock the clutch plates solid when it can. Or something like that. Needless to say, there are better solutions, and I know that there are more modern designs in some of the more expensive automobiles or concept cars. But, this technology has been around for decades...why is it just starting to come out now?

An automotive break system just seems scary when you think that just one leaky hose makes the whole car stop stopping. I've experienced this first hand, and luckily I wasn't going that fast. The fact that all 4 wheels work off the same hydraulic pressure is just insane. At least use some sort of pressure balancing valve to allow the other 2 or 3 wheels to continue to break if there is a leak somewhere else. Better yet, I've seen breaking by wire with electronics. That seems like the best way to do this, although many people will complain about the feel of the breaks. Is this why it hasn't been instituted yet?

An even more radical idea is DONT throttle the engine. Engines have two peak points. At one certain RPM, they create the most power. At another certain RPM, they run the most efficiently. So an engine should only ever be run at one of those RPM ranges. Yet, in every car I've ever seen, pushing the bettle throttles the engine. Most of the time, you are not running the engine at it's best performance mode. More money for the oil companies. Are you telling me that in this day and age there is no way to run the engine at a constant RPM and have the speed of the car adjusted in other ways, either by a smart transmission, or a torque converter that slips enough to optain the proper MPH desired? Of course, there are the new hybrid cars which work kind of on this idea. Use a smaller engine running at its peak efficiency to charge batteries and run the electric motors. Im sure theres a way to do this without having to resort to electronics as well.

I'm almost sure its possible to create a car these days that gets 10x the fuel efficiency than our current cars using the same gasoline products. Is poltics holding back progress? I dont know. I just wonder what happened to innovation. I guess big business kills that.


First...Transmissions don't have 10, 20 or 30 gears because of size, weight and cost constraints. Bicycles can have that many gears because they only have to handle maybe 1/4 horsepower at your peak output and the fact is humans don't produce anywhere near the range of power band an engine does.

Second...Wind resistance at freeway speed is in the range of 12 to 20 horsepower depending on what you drive and at what speed.

Third...Because of engine design principles such as intake and exhaust runner length, port scavenging, combustion chamber swirl, etc etc etc it is impossible to produce with any practical efficiency power out of an auto engine at 1000 rpm. To change the engines design to allow for 1000 rpm crusing would then destroy all effiency to be had at higher rpms. I believe it would infact be impossible to meet current emissions standards with an engine designed to cruise at such a low rpm.

Forth...Torque converters that lock are replacing older models fast. Very little time with a stick is spent in the 'slipping' condition. Sticks also have the advantage of being much lighter than automatics and cheaper to produce on average. Planetary gear sets are the optimum for machine controlled shifting since no meshing control is necessary. Currently the automatic tranny with lock up converter and computer controlled shift points and a carefully driven stick are the best forms of transmission for practical, efficient and reliable transportation.

Fifth...Hydraulic breaking systems on vehicles have not depended on one pressure circuit since the mid 60's. All vehicles now run two circuits out of the master cylinder allowing the car to maintain brake capacity even with a failed line or cylinder. I see no real upgrade to modern breaking systems that isn't already out there. Vented disc brakes at all four corners running semi metallic to metallic pads with some form of ABS is currently the best system to be had.

Sixth...As mentioned before there is no practical way to keep the engine at perfect rpm utilizing some intricate tranny. The weight, cost and lack of reliability would be to great. Engines have a decent range of rpm they can produce within 5% of there maximum volumetric efficiency at. This with current transmission technology is allowing for our cars to operate very close to the best they can.

Seventh...The gas/electric alternative is being researched and even marketed already. There are tradeoffs however that is still keeping them from being totally embraced by the consumer. These will slowly fall by the wayside as better and cheaper batteries and electric motors become available. BTW gas turbine/generator/battery/electric motor is the absolute best scenario for hybrid vehicle IMO.

It is impossible to increase fuel economy by 10 times and keep the same relative size, weight, safety and comfort we currently enjoy in our transportation. In fact I'm willing to bet it's impossible to achieve double the fuel economy of the most gas efficient car on the market today and still meet safety requirements and the original seating capacity. Sure you might be able to take a geo metro, lower it nearly to the ground, lower the roofline 4 inches, remove AC, Heat, radio, all the extra seats, shorten it 2 feet, put on even narrower tires and over inflate them, change gear ratios, retune the engine and you might get double the mileage....If it will pass safety inspection...

Vehicles innovations are very much 'driven' by the consumer and government safety/emission regulations.

[Player0]

1.) True, having multiple gears in a transmission is going to make it huge, if you want to keep it reliable. Space in a car is tight.

3.) I didnt say that cruising would have to be done at 1000rpm. It should be done at whatever RPM the engine happens to be the most efficient at. Acceleration should all happen at the point on the powercurve that the engine has the most power.

4.) Sticks are cheaper to produce only because they are still being produced. Price will follow technology as it is released. If consumers would adapt a more complicated transmission design, it would become cheap to produce as well.

5.) I dont know much about cars, but I know that when I blew a rusty hyrdraulic line on my wagon, my pedal went to the floor and I had to drive in to a snow pile to stop. Only one line failed. True, there is the emergency break but, thats a little unprecise for most emegerncy breaking. So, I dont know what kind of emergency system was built in to a 1987 Chevy wagon, but it wasn't working that night.

6.) Good point. The power curves on many modern engines arent THAT bad. You maybe have 1000-1500 RPM range where the efficiency is good. I know little about cars, and don think for one second I can design a better one. I was just describing some ideas of mine. The major topic I was trying to address was if the automobile manufacturers were limiting the options to consumers or not.

7.) Yeah those little hybrids look great. They have a ways to go, but once they are more accepted, the price will go down regardless if they are still as complicated to make.

There is no doubt in my mind that it is possible to build transportation which is much more safe, reliable and efficient. You say it is impossible to increase fuel efficieny 10x. Yet, it will eventually happen, maybe in our lifetimes. Technology will improve to that point, some new ingenious concepts will be developed that will make these kinds of cars possible. Of that, there is no doubt in my mind.

My real point was...what is the delay? The technology of computers grows exponentially, yet my car isn't much different than my dads or grandfathers. Obviously there has been some growth in the auto industry...but shouldnt it be progressing faster? And if so, whos to blame? The consumer? The big business? Surely the consumer wants a car that acts like they understand a car to act. And surely the automotive manufacturers in the world don't want to have to retool what they are doing or invest in technologies that will be slow to adapted.

So in the end, automotive technology is slower to grow than it should be. And it's probably everyones fault.

[Synthohol]

it may have been a renault, not peugeot..

[spldart]

There isn't 10x more energy to be harnessed in a gallon of gas. If you made a car under 2000 pounds with an engine the size of a motorcycles and implemented every engine technology imaginable you would be hard pressed to approach 100 mpg.
(variable valving, super lean burn, variable mixture, motor shuts off at lights, flywheel reclaims momentum on deceleration, electric motor assist, computer controlled shifting, super low coefficient of drag, composite body and frame for light weight, etc etc etc )
Mind you this is a hypothetical car that can pass safety tests and carry a driver, at least one passenger and some luggage and have some sort of comfort eminities.

There are almost no motorcycles capable of 100 mpg freeway and these are notoriously efficient on every count except aerodynamics in some cases.

[Synthohol]

im on the right track...
Check it out!!! (http://users.ox.ac.uk/~ball1245/MING%20Group%20Website_files/page0008.htm)

[Player0]

Actually, a single gallon of gas has enough power stored inside of it to power a car for its entire lifetime.

Unfortunetly, we have no way of harnessing that energy. Yet.

[Synthohol]

on a lighter note, a fart/methane engine would be very sufficent, once a week have 10-20 white castles and a half a case of budweiser. thats all you need. a little inpropriety and fill the tank yourself!

[Player0]

I love white castle. Ive never been to one myself though...none up here!!!!

[spldart]

Originally posted by Player0
Actually, a single gallon of gas has enough power stored inside of it to power a car for its entire lifetime.

Unfortunetly, we have no way of harnessing that energy. Yet.

If we are going to start counting the power that could be harnessed by using gasoline on an atomic level then gasoline is irrelevant. Any mass will do.

[Player0]

I just heard that on TV somewhere ;)

[speculative]

I agree with you on some things P0 - why isn't innovation in every industry though? I think the point that the market is driven by safety/government regulations is a big one though. That's why we didn't get the WRX until now, and why it's robbed of up to 40 hp with an exhaust system full of catalytic converters.

Maybe rotary engines will indeed catch on again - if they are reliable this time around. I like the idea and everyone I talk to says, "Oh, they're trying that again? (rx8) Maybe they'll be more reliable this time around." So I don't know if they have a good reputation.

Really though, let's face it - this country is more "rice" than "race." The enthusiast market is more full of people who would rather put on some bling-bling 20" rims than people who know the virtues of unsprung weight. ;)

-spec :djsmiles: