Urine Powered Generator Invented By Four African Girls

[Rich]

And a new rating. Miles per Lawsuit.

Actually, the construction methods I'm talking about are in fact stronger, AND safer.

Every race car is made with these techniques and principles.

You know that, and I know that, but do the Lawyers know that?

"Yer Honor, Aunt Bessie was jus' going to the store to get milk for her kittie, when the defendant slammed into her vehicle which came apart in a relatively low impact crash. While she appears unscathed, her emotional damage has scarred her psyche to her very roots. So we ask 25 million in compensary damages from both Slick Motors who manufactured such a deathtrap and Raceway Avengers who sold her on buying such a flimsy automobile."

"And yer honor, we ask for a jury trial."

[Greg]

? I never heard of a Lotus referred to as a death trap?

Comparatively speaking, while a Lotus is safe(possibly safer than a sedan due to better handling and braking) it is still going to lose every time a much larger vehicle is involved. There's no way around it, there will ALWAYS be trucks on the road. Not simply large commercial vehicles, but there will always be larger "light duty" trucks tooling about from contractors tool body trucks and delivery vans to 3/4-1 ton trucks towing/carrying some form of freight. If you had a choice, would you take an Elise or an early 80's Caddy into a demolition derby?

I was going to say something about playing bumper cars with a 3-ton SUV, but your way is better.

A sports car is fantastic for avoiding collisions, unless you're doing something stupid on public roads that you really shouldn't. Will even be better in a rollover than any typical passenger car and likely safer in many other kinds of single-vehicle accidents (seat, harness, safety-cage, etc). But in a multi-vehicle collisions with other, much heavier vehicles? I don't like the physics.

[Aglifter]

Weight doesn't indicate anything in a collision other than how the resultant vectors will work out.

An F1 car driver can survive staggeringly high energy impacts.

For controlled failure points, metal makes sense - although I could be wrong about that.

[Greg]

Weight doesn't indicate anything in a collision other than how the resultant vectors will work out.

Well yes, that's rather the whole point. How the resultant vectors work out determines who has to endure what level of acceleration, and who has to absorb what level of energy. The lighter you are, the more of both. Neither are desirable.

An F1 car driver can survive staggeringly high energy impacts.

Yes. And when street cars are engineered to F1 levels we'll talk again. (I did say something about drastically lighter cars winding up much more expensive.) A Lotus isn't a F1 car, though.

For now, in a collision steel is the shit. The fact that it's heavy is good. The fact that it can be designed to deform in very well controlled ways and absorb enormous amounts of crash energy in so doing, and do it with a cheap, easily made structure... is unmatched. I also mentioned we know how to do very clever things with steel. (Mind you that paradoxically, excessively rigid steel structures can be worse in collisions than steel structures that deform.)

[HTRN]

Also, F1s and by extension Indycars, are both extremely light. How they get away with drivers surviving impacts at speeds that your average street car will never see is simple, they're designed to self destruct - all that energy goes into shredding the car, instead of killing the driver. Add in a nice little safety cage around the driver and you have something that is remarkably survivable...

The downside is the kind of damage they suffer from minor collisions - tell somebody their minor fender bender means that their 2 year old 40K dollar car, that they're still making payments on, is basically totaled, and you'll have lawsuits flying left and right.

[Netpackrat]

Also, F1s and by extension Indycars, are both extremely light. How they get away with drivers surviving impacts at speeds that your average street car will never see is simple, they're designed to self destruct - all that energy goes into shredding the car, instead of killing the driver. Add in a nice little safety cage around the driver and you have something that is remarkably survivable...

I'm not up on modern race car design, but I'm gonna bet that safety cage is made out of steel.

[Netpackrat]

IF federal law mandates a 50+ mpg fleet average, that's the price we are going to have to pay. There really isn't another option.

There is no "we" here. I reject the idea in its entirety, and so will 99% of motorists, once they find out how much it will cost to repair and maintain, let alone purchase. What you can do in aerospace and racing with exotic composites is a far cry from what you can realistically expect with a motor vehicle in general service, that will have to be operated, maintained, and repaired by ordinary human beings. I for one, do not want to share a highway with a vehicle built of advanced composites, that has been repaired under the conditions prevalent in the typical auto body shop, by the sort of people who will be working on them.

[esa5444]

For controlled failure points, metal makes sense - although I could be wrong about that.

Metal, specifically steel, makes the most sense of any material we use, unless we make wooden cars.

1. Cheap and abundant. There is enough steel to allow us to make all the cars we use. If you start using aluminum, polymers, composites, it will be mind-boggling expensive and there will be a limited supply.
2. Easy to form. With any material that could replace metal in cars, the processes do not easily lend themselves to large scale production. You can stamp out car doors from steel, cheap, fast, and with consistent quality. You can not stamp out composites and high strength polymers and still guarantee their strength and integrity unless you test each one individually. Not economically feasible.
3. Fatigue. Steel has this wonderful quality that below a certain stress, it does not suffer from metal fatigue. If you use aluminum, plastics, composites, the cars will have a fatigue life. This will mean cars will require inspection for fatigue, or next thing you know, you will drive down the street and your car will crack in half. Most people can not get their oil changed on time. Cars prone to fatigue is asking for trouble.
4. Isotropy. Steel has another wonderful quality. It has the same strength regardless of direction. Composites do not. With the kind of abuse cars take, you will have delamination and all sorts of other failures.

The fact is that if you build and maintain cars like airplanes, you can make the F1 race cars, at the price of airplanes and race cars. If you make cars that people can afford and will stand up to the daily abuse they have to take, you are locked into using steel.

On top of that, cars are not just transportation devices. They are status symbols, escapes for the frustrations of life, entertainment, etc. you can make a 2000 lbs car of steel that will comfortably seat 4 people. But it will not be well met. If we use the analogy that cars are ships, most people are expecting something like a cruise ship, where they are very isolated from the reality of them being on a machine. If you build a 2000 lbs car, it will be like a warship. It will have all the creature comforts, but it will have conduits exposed and it will be impossible to pretend a car is a lounge chair on wheels. People are vain, stupid, illogical and a car that is guided by choices that were purely technical will fail in the market.

[Netpackrat]

Yeah, it would be a situation where you couldn't actually repair the components once damaged, they'd have to be replaced. That's why they'd need to be modular construction.

Modular construction can only do so much, because you're still going to have collision forces transmitted to the frame. If that frame is made of steel, you can take some measurements between cardinal points, and see if it is straight, and straighten it if necessary. You check it for signs of damage (cracks, buckling, corrosion, etc) and if it looks good, you can be reasonably certain that it IS good. Furthermore, if it isn't good, you can almost always MAKE it good via metal replacement using good, old fashioned, welding technology.

If the frame is made of composite material, after a collision, you're going to have something that is either obviously broken, or straight. It can still be structurally compromised, and straight, with no obvious sign of damage. Inspeccting it for damage means you need to have it tested using ultrasonic non-destructive testing (UT). Having qualified as a UT technician, I can guarantee you that the chance of finding somebody capable of doing that work at an autobody shop is vanishingly small. In practice, composite frames will either not be inspected at all post-collision (leading to hidden flaws causing accidents later on), or repair work that approaches (or exceeds) the cost of buying a new vehicle. I wouldn't be too surprised if they have to come up with a law mandating frame replacement for accidents above a certain severity, as determined by sensors.

[Erik]

Stupid question, but would replacing modular parts really be much more expensive than repairing them? You'd save a lot of time on inspections and repair time.
And isn't that what they usually do with steel parts now anyway? If you're in small fender bender they'll just replace the parts, when previously they would have hammered them out. I've been told it's because newer cars are designed with impact zones, that are supposed to give way, and once it's done its job it must be replaced.

I once had someone bump into my car so light that the actual fender hardly showed any damage, but the structure behind it had been compromised and needed to be replaced.