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Rigby5
User Rank
Gold
Re: 70 lbs is a lot of wiring
Rigby5   9/21/2012 1:16:51 PM
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We have already done the studies and found the solution as well.  The thickness of the wire requirement is based on current, not voltage, and for a given work, one can just increase the voltage, and the current and wire size reduces propotionally.

So if you want half the wire weight, just increase the voltage from 12 to 24.

There is no reason not to go to 48 even.

The added advantage is that then it will be much easier to provide clean 12 volt DC for electrical components that have great difficulty with dirty 12 volt systems we have now.

Rigby5
User Rank
Gold
Re: Fuel technologies
Rigby5   9/21/2012 1:11:37 PM
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Watashhi,

Dune buggies can easily take high speed roll overs with no problem or damage to the roll cage.  If you used the same material to make a roll cage for a large luxury car, it would never hold up.  It could not even take the weight, much less impact.


The Smartcar is an example of how the smaller a vehicle gets, the greater the strenght to weight ratio.  Another was the old aircooled VW, which had amazing strength to weight ratio advantages, and is why it is still the basis for most dune buggies.  When you examine larger vehicles, like Cadillacs or limosines, you find that they are weaker in all aspects, because of all the extra weight.  It is not possible to scale up the strength to keep up with the weight increases caused by the strengthening attempt itself. 

Just examine actual accident damage.  You will find with heavier vehicles, there is often total penetration of passenger compartments, with things like side intrusion, etc.  While with lighter vehicles, the main structure tends to stay more intact, and the danger to the passengers is more from whiplash as the vehicle tends to bounce off of impacts.

Or you can just study the animal kingdom to see the physics.  You won't see animals larger than the elephant on land, because they simply exceed the practical strength to weight ratio.  While anyone who has tried to crush a flea knows how difficult that can be.

Rigby5
User Rank
Gold
Re: The real gorilla
Rigby5   9/21/2012 12:55:32 PM
J.Williams,

I agree that mpg is on everyone's mind when gas prices go up, but not ahead of time when it could make a difference.  We have had over 3 major gasoline shortages and price spikes in the last 40 years, and each time US auto makers were totally unprepared, nearly failed, and required expensive taxpayer bailouts.

The rest of the world has also already tried the free market, and it has always failed when it comes to vehicle mileage.  Everyone only wants everyone else to use less gasoline, so that it will be cheaper for their beheamoth.  So I see no way around regulations at the means.

If vehicle buyers had any sense at all, they would not be buying silly, heavy, fragile, and expensive things like power seats, power windows, power locks, remote start, keyless entry, etc.  Although car makers have to take part of the blame for not being honest about how these things harm reliability and mileage.

Rigby5
User Rank
Gold
Re: Why cylinder deactivation?
Rigby5   9/21/2012 12:45:04 PM
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Yes, I agree.  Things like more gears, higher reving, variable supercharging, and direct injection to eliminate pre-ignition, would allow a smaller and lighter engine to still have sufficient hp potential, without all the extra weight of a larger engine.  Deactivation does not make the wasted weight of the deactivated cylinders to go away.

Rigby5
User Rank
Gold
Re: Smogasbord of Innovation
Rigby5   9/21/2012 12:40:54 PM
Ragtoplvr,

I agree that added complexity is not the answer.  That is why I am skeptical of hybreds.  They more than double the possibibility of major component failure, and double the weight of the propulsion systems.

But some some ideas, such as regenerative braking, are simple and could easily reduce fuel comsumption by half.  If brakes enaged an air compressor or flywheel, that energy could be used over and over again instead of being wasted, and it is not a very complex system.

And I agree about the hazards of aluminum wire.  It was tried in homes in the 1950's, with terrible results.  If one wants to reduce weight from wires, the easier solution is just to increase voltage from 12 to 24 or 48, because then wires can be extremely thin, and still carry the same wattage safely.

Absalom
User Rank
Gold
Re: Fuel technologies
Absalom   9/21/2012 12:15:53 PM
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I hope these theories about tiny cars being safe turn out to be true and nobody gets hurt. However, I'm keeping my big truck with it's 300 lb. front bumper and stout steel tube roll bar.

Absalom
User Rank
Gold
Re: Fossil Fuel Free Vehicles
Absalom   9/20/2012 6:09:53 PM
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Head on collisions with anything are pretty final. Hit from behind and run into the guard rail are the threats I've experience from trucks. I suppose a good crush zone helps protect you from the first and a .44 mag handles the second. I still prefer something in the 8000 pound range for general use.

Watashi
User Rank
Platinum
Re: Fuel technologies
Watashi   9/20/2012 1:16:29 PM
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Respectfully, cages are not that different between vehicles.  You only protect the passenger compartment.  In fact, "dune buggies" or "sand rails" have a bit more expensive cage since the cage is also their main structure (chassis).

I agree with you that for this discussion the focus should be on collisions between passenger cars, including light trucks.  Collisions with large trucks have been and always will be catastrophic at medium to high speeds.

Rigby5
User Rank
Gold
Re: Fossil Fuel Free Vehicles
Rigby5   9/20/2012 12:22:12 AM
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I agree.

Batteries are always going to be expensive, hot, slow to recharge, and still need energy from somewhere.


I never heard of an inert gas plasma motor either, but here is a link:

http://pesn.com/2009/07/18/9501554_Plasma_Transition_Process_motor_system/

But I am not convinced.

Cold fusion is a bust from what I have read, and hot fusion will always be too big and heavy, if they ever get it to be practical at all.

I think biofuel is going to be our only fall back for a couple of centuries at least, and that is far smaller in quantity than the oil we use now.

Rigby5
User Rank
Gold
Re: Fuel technologies
Rigby5   9/20/2012 12:12:36 AM
NO RATINGS
Trucks are irrelvant because nothing is going to survive a head on with a truck.  Your only hope with a truck is to avoid a head on, and the smaller your vehicle, the easier to manuver and avoid the truck. 

Safety cages are easier on lighter vehicles.  Dune buggies are easy to make a safety cage for because they are light.  If you had to make a safety cage for a big truck or even a Cadillac, it would be essentially impossible.  The heavier the object is, the worse the strength to weight ratio.  There is no way around the laws of physiscs.  That is why an ant can lift 100 times its own weight, and we can't.  We are too big.  Small cars are inherently stronger. 

The only problem is when 2 vehicles collide head on, then whomever has the greatest mass, will destroy the other vehicle.  And the solution to that is not have head on collisions, or try to make all vehicles smaller.

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