05-28-2009, 12:24 AM
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#101 (permalink)
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Wannabe greenie
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Quote:
Originally Posted by evolutionmovement
5-point harnesses not bolted to a near horizontal surface (like a roll cage) can cause spinal compression. Fun.
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Plus, if you're not wearing a helmet tethered to the roll bar, you'll end up Earnhardted. A five point with no helmet is probably worse without an airbag.
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05-28-2009, 08:57 AM
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#102 (permalink)
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Master EcoModder
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Quote:
Originally Posted by evolutionmovement
5-point harnesses not bolted to a near horizontal surface (like a roll cage) can cause spinal compression. Fun.
And stretching out the length of the collision is the point of auto-tensioning belts and airbags, is as some_other_dave mentioned. They're supposed to allow movement with the idea of preventing internal brain injuries like the one that killed Dale Earnhardt.
That said, most of the weight comes from all the crumble zones and, in smaller cars, engineering them to be able to have a chance against the land ironclads so many other people choose to drive. Seat belts are a minor weight addition. Airbags wouldn't be too bad were it not for there being so damn many of them now. Cars are way too safe now, allowing people to do stupid things like text and drive with little worry of the consequence (yet, conversely, or maybe in awareness of their stupidity, they tend to buy cars based on perceptions of safety) that they'd be unlikely to do if the likely consequences were greater. I probably average seeing about a collision a day commuting to and from work, yet despite what looks like expensive damage (and I'm sure it is as even some idiot denting my Mazda3 in the parking lot cost $2500), everybody involved are usually standing around looking bored awaiting state police/tow truck (while raising insurance rates for the rest everyone).
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Which do you think costs more: reparing/replacing a vehicle or injuring/killing the occupants? Safety devices save lives and reduce total costs. Have you ever seen a bill from a trip to the emergency room?
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05-28-2009, 12:00 PM
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#103 (permalink)
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EcoModding Apprentice
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Cheapest is collisions involving cars with less weight. Hatchbacks wouldn't need to weigh 3000 lbs. to be safe if the likelihood of getting hit by something weighing near 5000 lbs. and attempting passenger survivability wasn't so likely. And what kind of injuries are we talking? I'd rather die in a crash than end up paralyzed, sucking limited resources away from fully-functioning people who could use them better. How many kids could go to college for what it costs to maintain a helpless person for a 4-year period? As I said, cars are too safe. It's been shown in traffic studies that people drive worse in cars that are perceived to be safer. Less accidents altogether is even cheaper. As an extreme example, install a spear point in the center of the steering wheel (not too far from what they had on many cars in the '50's) and see how much better people pay attention. Cheapest still, would be making a license hard to get, but the government screwed that decades ago when they redesigned the country around the automobile, making only select cities a place where not owning an automobile and still being able to have a real job is a practical possibility. But people don't want practical redesigns of the existing poor infrastructure, they want to keep Mickey Mousing the status quo. Humans. Where are the replacements?
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05-28-2009, 02:35 PM
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#104 (permalink)
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Master EcoModder
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Quote:
Originally Posted by evolutionmovement
Cheapest is collisions involving cars with less weight. Hatchbacks wouldn't need to weigh 3000 lbs. to be safe if the likelihood of getting hit by something weighing near 5000 lbs. and attempting passenger survivability wasn't so likely. And what kind of injuries are we talking? I'd rather die in a crash than end up paralyzed, sucking limited resources away from fully-functioning people who could use them better. How many kids could go to college for what it costs to maintain a helpless person for a 4-year period? As I said, cars are too safe. It's been shown in traffic studies that people drive worse in cars that are perceived to be safer. Less accidents altogether is even cheaper. As an extreme example, install a spear point in the center of the steering wheel (not too far from what they had on many cars in the '50's) and see how much better people pay attention. Cheapest still, would be making a license hard to get, but the government screwed that decades ago when they redesigned the country around the automobile, making only select cities a place where not owning an automobile and still being able to have a real job is a practical possibility. But people don't want practical redesigns of the existing poor infrastructure, they want to keep Mickey Mousing the status quo. Humans. Where are the replacements?
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The problem with your logic is it assumes that all parties involved in the accident are at fault. If I'm hit by someone who isn't paying attention I want every safety feature known to man so I might survive the crash.
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05-28-2009, 04:33 PM
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#105 (permalink)
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Master EcoModder
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Yes I have racing seats and yes my belts are tethered into the rear support frame(the Del Sol has a near roll cage support column coming up behind the seats, the bottoms are bolted into the chassis reinforced frame points(it has a raised ridge of thickened steel for the seat belts.))
Auto tensioning seat belts are not the safety feature. Belt elasticity is. I've worked with ropes and tubular webbing(what our seat belt is made of) for a long time. When climbing you have a special length of rope(if its likely you will experience a hard fall) that is between the climber and the belay rope. Its much more elastic than the dynamic rope. The idea is it stretches to accomodate the fall over a greater distance.
Pre/auto-tensioning just makes sure that the belt doesn't act like static rope(lets you fall until your reach rope length and then moves not one millimeter further). If you didn't have pre/auto-tensioners your seat belt would be whatever length you adjusted it to when you got in and sat down. If its already tight against your body its utterly irrelevant. What you want then is a "zorber" thats a pully rigged to a very strong spring. You can't make it give by hand. On a press you can extend it but you had better be clear when it lets go. . .
At the moment the wreck starts is not the moment of impact. When your body first presses against the seat belt is when the strain will be greatest because its not stretching the belt and the shock absorber hasvn't been breached yet because it takes a fraction of a second for those mechanisms to engage. When that event happens the air bags are not deployed. They have a chemical compound (NaN3?) that produces NaN and N2 when shaken or shocked. IT happens incredibly fast but the passengers are already expanding the seat belts and have experienced the harshest of the acceleration on their chest.
Yes I am very familiar with HANS, but I'm not ever travelling fast enough for it to matter. It takes an incredible amount of force to create an "earnhardt" event. He was doing almost 200 mph(3x faster than my speed) and was wearing a 4 lb helmet(mass thats still going to want to accelerate). The most acceleration I can do is a few feet per second in reverse from 60 mph. The most I can achieve is less than 1/3 the acceleration and only 60% the amount of mass.
I've already said I am not opposed to frontal airbags. They are useful at decelerating head and neck, its just the other ones that don't make alot of sense.
I have a friend still in the hospital from a car wreck. She had frontal airbags and no side air bags. She was t-boned at 65 by a truck while she was in a Honda Civic 97. She broke both of her legs(at the Femur) and almost bled to death internally from the damage to her legs. No injuries to her head whatsoever. No injuries to any other part of her body whatsoever. Her passenger(who had no airbags) had no injuries other than a broken clavicle and her splean ruptured, both results from the seat belt not any other impact. I'm not saying the seat belts were bad, they saved their lives, but at the extremes of the spectrum(truck-car, T-boned, nearly highest speed possible fora collision) the other safety features would have been absolutely useless and probably caused more damage.
Thats why I haven't been on I had to drive to visit her yesterday. You can say I am uninformed and not involved but I've seen both of the cars and I've seen the injuries and I stick with my story. Frontals are fine, curtains, pillars and rear useless. They both agree they are glad they didn't get smashed by another (the first) set of air bags from the sides.
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05-28-2009, 10:23 PM
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#106 (permalink)
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EcoModding Apprentice
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Quote:
Originally Posted by basjoos
Another possible engine/tranny swap would be to use the 50 hp/74 ft-lbs unit from the diesel version of the Smart fourtwo. That's what's being used in the current version of the Avion, an automotive X-prize contender that's getting well over 100 mpg.
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To my knowledge, no one has ever managed to get a new version smart diesel engine to work out of a smart car without a LOT of help from Mercedes. And Mercedes help is Expensive. Everything is electronically integrated to the car. Incidentally, no one has ever stolen a 450 or 451 without the key either. I will say though, that engine is a beast. Pulls like snot starting from about 1600 RPM. (My previous car was a diesel 450).
If you put an efficient engine in an insight, your highway mileage will be similar, your city mileage will suffer.
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05-28-2009, 10:30 PM
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#107 (permalink)
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Master EcoModder
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Quote:
Originally Posted by stevey_frac
To my knowledge, no one has ever managed to get a new version smart diesel engine to work out of a smart car without a LOT of help from Mercedes. And Mercedes help is Expensive. Everything is electronically integrated to the car. Incidentally, no one has ever stolen a 450 or 451 without the key either. I will say though, that engine is a beast. Pulls like snot starting from about 1600 RPM. (My previous car was a diesel 450).
If you put an efficient engine in an insight, your highway mileage will be similar, your city mileage will suffer.
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I agree that the smart fourtwo would be a great replacement. . .but. . .I don't know that its actually possible.
Changing powerplants almost always requires extensive fabrication(unless its from a similar make and model) and integration with expensive aftermarket ECUs, unless you want to run them in a hampered mode.
Stick with the Insight's systems and just drop the hybrid components and get her as light as possible adding as much aero for as little weight as is possible.
Without any extra components, maybe some solar to replace the alt along with suspension regenerators you should be able to lay down some serious FE.
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05-29-2009, 03:30 AM
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#108 (permalink)
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Civic 4 Life
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Full boattail please?
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05-29-2009, 07:20 AM
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#109 (permalink)
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EcoModding Apprentice
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Quote:
Originally Posted by theunchosen
I agree that the smart fourtwo would be a great replacement. . .but. . .I don't know that its actually possible.
Changing powerplants almost always requires extensive fabrication(unless its from a similar make and model) and integration with expensive aftermarket ECUs, unless you want to run them in a hampered mode.
Stick with the Insight's systems and just drop the hybrid components and get her as light as possible adding as much aero for as little weight as is possible.
Without any extra components, maybe some solar to replace the alt along with suspension regenerators you should be able to lay down some serious FE.
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Not something i've looked up, but can you even get an aftermarket ECU to run a common rail diesel system?
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05-29-2009, 10:05 AM
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#110 (permalink)
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Master EcoModder
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You can get an aftermarket anything lol. The lol is considering the weird junk you can find for aftermarket parts. I'm not very familiar with diesels so maybe you can't get the ECU, but if I had to guess you can.
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