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Discussion Starter #1
Now that I have your attention. :wink:

I have been experimenting with a home made hydrogen system (electric + water= hydrogen, oxygen) on an 83 Mercedes, but it didn’t do a whole lot seeing as the car had no computers to speak of in it, and therefore could not compensate for the extra BTUs being dumped into the engine. I am the proud owner of a 2005 #4 seaside pearl Prius, and I would love to test the system on the Prius, but I figured I would check and see if any of you had any advice first. A few design problems to look at with the system, the first and foremost is the problem of a pocket of hydrogen building up in the ICE intake when it is inactive, and then being sucked into the engine when it reactivates, and BOOM, that would not make me a happy camper. I’m no chemist, so I’m not sure on the BTU yield of my system. Another interesting idea is to tap into the 500v electric system instead of the 12v to power the hydrogen generator, and possibly get more out of it.

Lemme know what you guys think, ill be happy to answer any questions you guys have about my little contraption.

... and YES I know this will void my warranty :p
 

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Someone in Germany has converted the ICE on a THSII Prius to run on hydrogen stored in solids. Was featured in a Public Television documentary with Alan Alda.

If I find the link, I'll post it.
 

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Discussion Starter #3
Yea but I cant imagine solid hydrogen being that cheap, and last I checked, waters free most places. 8)
 

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If I understand your post correctly, it sounds like you intend to use the car's electric system to split water into hydrogen and oxygen, then feed the hydrogen into the engine's intake manifold.

It's important to realize that it will take more electric energy from your car (whether you use the 12V or 200V/500V system) than you could ever get back by burning the hydrogen.

To paraphrase the three laws of thermodynamics:

You can't win, you can't break even, and you can't leave the game :p

In other words, there's no such thing as a perpetual motion machine.

If I've misinterpreted your proposal, please correct me.
 

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Discussion Starter #5
RSnyder said:
If I understand your post correctly, it sounds like you intend to use the car's electric system to split water into hydrogen and oxygen, then feed the hydrogen into the engine's intake manifold.

It's important to realize that it will take more electric energy from your car (whether you use the 12V or 200V/500V system) than you could ever get back by burning the hydrogen.

To paraphrase the three laws of thermodynamics:

You can't win, you can't break even, and you can't leave the game :p

In other words, there's no such thing as a perpetual motion machine.

If I've misinterpreted your proposal, please correct me.
You foget thought that by converting water to hydrogen and oxygen you are adding to the energy equasion, its not perpertual motion. I would just be using the water to create energy on top of gasoline. Its a proven method of increasing MPG if you look around at some of the home brew systems online, but in most cases to see a marked increase your car must be equiped with a computer, so that the car knows to back off the gas, because you are adding another volitile component, namely hydrogen.
 

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One other issue you'll have is with the Atkinson/Miller cycle in the Prius, by design you have reversion of the charge back into the intake for use by other cylinders, since at BDC the valve isn't closed on the compression stroke.

FYI, the engine is mechanically spun up to 1000rpm before it's lit, and it's drive by wire, so you'll not be able to use throttle position for release. Two items that are going to cause you problems. Maybe 4 feed lines with induciton sensors at the spark plugs, but then you're going to be changing the fuel charge past the sensors. Ok if your only talking a small bit.

Wouldn't it be easier to run nitrous oxide infront of the mass air flow sensor? A small dribble would help the charge temp, but the reversion pops would be VERY loud. And you may have the emissions system fighting you too...

Might be better off purchasing a drum of 100 octane unleaded race fuel and cutting it with regular 87 unleaded. There isn't any ethanol in the race gas, and the regular 87 would add some detergents and reduce the octane level a tad, as well as the bite of your wallet. A better gas to ethanol ratio will help your mileage. :D

Paulie (who's other car is a 2000 Camaro Z28 that runs 11.80's in the quarter without spray, but is a terrible commuter car)
 

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Discussion Starter #7
Thanx Paulie, thats just the kind of imput im looking for, and I didnt know about the reversion. While those are all great ideas Paulie, the idea here is to save money, and improve MPG. Water is basicaly free, Nitros, and racing fuel, I can't imagine being any cheaper than regular gas so is kinda taking a step backwards. Any other ideas would be apreciated. Thanx again.
 

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toxygen said:
You foget thought that by converting water to hydrogen and oxygen you are adding to the energy equasion, its not perpertual motion. I would just be using the water to create energy on top of gasoline. Its a proven method of increasing MPG if you look around at some of the home brew systems online, but in most cases to see a marked increase your car must be equiped with a computer, so that the car knows to back off the gas, because you are adding another volitile component, namely hydrogen.
My understanding of your original post is that you want to use the car's electricity to convert water to H2 and O2. If that's the case, then you are not adding energy to the equation. Now if you're using your household electricity to convert water to H2 and O2, then you are adding your house's energy supply to the equation. But then you have the additional headache of transporting Hydrogen.
 

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DanMan32 said:
Someone in Germany has converted the ICE on a THSII Prius to run on hydrogen stored in solids. Was featured in a Public Television documentary with Alan Alda.

If I find the link, I'll post it.
It was the inventor of the NiMH battery that developed the storage system, and Solid was the storage system for the hydrogen. The Hydrogen was gaseous when burned. It was a G2 Prius that was being used as a test bed. The point was a safer and more efficient storage system for Hydrogen.
 

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toxygen said:
I have been experimenting with a home made hydrogen system (electric + water= hydrogen, oxygen) on an 83 Mercedes, but it didn’t do a whole lot seeing as the car had no computers to speak of in it, and therefore could not compensate for the extra BTUs being dumped into the engine.
I don't think BTU's are the issue there. The issue is that a non-closed-loop system cannot change its air/fuel ratio to deal with an increase in fuel. A closed-loop system MAY be able to do that as long as the amount introduced is small. Closed loop control would reduce the amount of fuel injected to maintain stochiometric combustion, thus saving fuel.

Another interesting idea is to tap into the 500v electric system instead of the 12v to power the hydrogen generator, and possibly get more out of it.
Not sure why you would do that. Even excellent hydrolysis rigs only get around 80% efficiency out of the system. Combine that with a 40% overall thermodynamic efficiency for the combustion process, and you would be taking 10kW of power that could be going to the electric motor and turning it into 3kW of motive power. It would seem to be more efficient to just sent it to the motor where it could get converted into around 9.5kW of motive power.

In addition, electrolysis occurs most efficiently at 2 volts. Unless you have a converter to step 500 volts at 1 amp down to 2 volts at 250 amps, you'll be wasting 99+% of the power.

Now, if you're talking about making hydrogen and storing it, that's a different story. A tanked-hydrogen system might well increase your fuel economy, but would also cause the computer a bit of trouble, since it would have to deal with constantly varying power outputs for a given throttle setting. But it might be interesting to attempt.
 

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I'm pretty sure there are some Prii running around California converted to H2 use (ICE, not fuel cell), so it's not the hardest conversion in the world to do (info here). Guessing that you're making your H2 at home with an electrolyser, it would make much more sense to use that electricity to charge an extra onboard battery (waaaay less losses and probably lighter too), as the same amount of electricity should give you 4 times the range improvement.
 

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Discussion Starter #13
Thank you all for your input, I currently dont pay for electricity, it is included in my rent so i may try 2v eletrolisis rig, stepped down from house current, and try to load the h2 and o2 into a tank and see what happens! I'll keep you posted.
 

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toxygen said:
Thank you all for your input, I currently dont pay for electricity, it is included in my rent so i may try 2v eletrolisis rig, stepped down from house current, and try to load the h2 and o2 into a tank and see what happens! I'll keep you posted.
Be very careful about how much pure O2 you let into the system, it won't take much before the computers can't control predetonation (knocking). If you're lucky, they'll be programmed to shut down. If not, the engine will be damaged.

Even a little bit could raise the combustion temperature enough to form lots of NOx and get you a check engine light.

If you're high in the mountains, adding a bit of O2 could be beneficial, but if you're close to sea level, I wouldn't even bother.
 

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hyperion said:
If it could have been done better don't you think Toyota would have done it?
Toyota have to think about their bottom line - they can't afford to put out the technology their engineers would like to see on the roads as it would never be reflected in profits.

The 150 mpg plug-in Prius is a fine example of how much improvement can be made over the standard design with just a minor modification. However it's still just a little too expensive for Toyota bosses to consider manufacturing at the moment (it would add roughly another $2,500 to the manufacturing cost of the car).
 

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toxygen said:
Thank you all for your input, I currently dont pay for electricity, it is included in my rent so i may try 2v eletrolisis rig, stepped down from house current, and try to load the h2 and o2 into a tank and see what happens! I'll keep you posted.
Free electricity? Not for long, once they see their electric bill skyrocket. Sounds dangerous to me. Better take on extra insurance.
 

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toxygen said:
Thank you all for your input, I currently dont pay for electricity, it is included in my rent so i may try 2v eletrolisis rig, stepped down from house current, and try to load the h2 and o2 into a tank and see what happens! I'll keep you posted.
uh. Don't do that. h2 and o2 in the same tank is called a fuel air explosive. A bomb. If you somehow get a tiny spark in that thing you are going to blow yourself up.

h2 and o2 go in separate tanks. don't let them combine outside the combustion chamber.
 

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SkipHuffman said:
uh. Don't do that. h2 and o2 in the same tank is called a fuel air explosive. A bomb. If you somehow get a tiny spark in that thing you are going to blow yourself up.

h2 and o2 go in separate tanks. don't let them combine outside the combustion chamber.
I remember that (on a very small scale) from 8th grade science class. My lab partner and I blew up a test tube. Who knew? It sure got our attention, though. :oops:
 
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