BoyntonStu
02-13-2009, 11:03 PM
From: water4gas@yahoogroups.com on behalf of djmikewalsh@aol.com
Sent: Fri 2/13/09 5:40 PM
To: Water4Gas@yahoogroups.com
OBDII systems were specifically designed first and foremost to regulate the emissions of our vehicles and to create a set standard by which all manufacturers could meet compliance for those modern emissions requirements, governed by the EPA. Most people don't realize that the most common factory set air to fuel ratio on our vehicles, 14.7:1, is set as a compromise between performance, economy, and emissions. The primary reason it is set there is for emissions purposes. It's to have enough left over fuel/hydrocarbons exiting the exhaust to heat the catalytic converter, as the cat cannot do it's job at breaking down hydrocarbons through catalysis unless it's up to its full operating temperature range, which happens to be between 600 and 1500 degrees F. So the whole modern combustion process is a catch-22. Even a modern internal combustion engine already has a limited efficiency by design before worrying about emissions, but because we need to limit emissions we waste even more fuel and operate at even lower efficiency by throwing more accelerant (unburned fuel) on the catalytic convertor to keep it hot. It's obvious that if you can stop the catch 22 and burn all the fuel in the engine without sending it out to the cat there's plenty of mileage to be gained there.
When any working fuel economy device is used it immediately begins to alter the content in the exhaust. A true increase in combustion efficiency will produce less emissions there. ( For any doubts about whether hydroxy or even less potent pure hydrogen gas has the ability to alter combustion efficiency consult the web published research of NASA, MIT, and the US D.O.T. ) Less emissions are immediately detected by the O2/AFR sensors if the reduction is dramatic enough. Since the ECU is programmed to maintain the temperature of the catalytic convertor and see the amount of oxygen relevant to the 14.7:1 AFR, the ECU will not allow alterations in economy. It will counter them by increasing the fuel injection rate so that the cat temps are maintained and the oxygen levels detected are nominal for 14.7:1. This is why injecting hydroxy while doing nothing else usually produces a negative effect on mileage. In a vicious circle the hydroxy improves the burn, the hydrocarbons are reduced, it's detected in the exhaust by the o2 sensors, and more fuel is added until the sensor parameters return to normal.
Hydroxy experimenters counter this by using an EFIE (Electronic Fuel Injection Enhancer). Dutchman uses their Optimizer3x. Basically what the devices do is make up for the loss of hydrocarbons in the exhaust electronically. A typical o2 sensor has an operating range of .1-1.2volts. .1 volts would be interpreted as lean and 1.2 volts would be rich. .5 volts represents the targeted 14.7:1 AFR. As the hydrocarbons go down in the exhaust the average voltage of the o2 sensor to the ECU also follows. An EFIE or Optimizer3x will add voltage to the o2 sensor to bring the average back up to around .5v and take away the ECU's ability to detect a difference in exhaust, however that is far from the end of the battle with the ECU. Most OBDII vehicles use downstream sensors, that is, o2 sensors located on the exhaust pipe after the catalytic converter, to monitor catalytic converter temps as well as hydrocarbon emissions.
So lets say you're running hydroxy, combustion efficiency is increased, the exhausted hydrocarbons go down, and you've successfully returned the o2 sensor's readings to average .5 volts with an EFIE. Without those hydrocarbons heating up the catalytic convertor to operating temperature another alarm goes off in the ECU because cat temps have dropped dramatically, and fuel is once again added to balance the equation. Can you begin to see how difficult this is to get working? Not to mention that EFIE design leaves much to be desired, because it's impossible to set one voltage offset for added voltage and have it be correct in all environmental variables and driving conditions. The only correct way to do this would be to use the incoming o2 sensor signal and other ECU parameters such as ambient temp, or ambient MAP pressure as a reference to determine the proper voltage offset to equal a simulated 14.7:1 for the ECU all the time. Unfortunately I don't know of anyone that has invented such a device.
What I've written here is just the tip of the iceberg of what experimenters are trying to do with our modifications. There's much more. With the increase in flame propagation speed within the combustion chamber provided by added hydroxy, the stock ignition timing is not optimal for both performance and for emissions. There's greater mileage, performance, and a reduction of emissions to be gained by retarding the ignition timing to optimize the combustion further. In the old days you could alter this with just a turn of the distributor cap and a timing light, but these days on most cars the ECU automatically determines engine timing, mostly based on the IAT (Intake Air Temp) sensor. To deal with this we add resistance in parallel with the sensor and alter voltages to the ECU. Higher perceived temps for the ECU will retard timing, and that is what is simulated, but the IAT temp can't be the only one that's seen high or the ECU will not accept it, and a check engine light will illuminate. If the coolant temp also appears higher the ECU will comply with the changing of the timing without hesitation, so the same parallel resistance technique is applied to the CTS sensor. Just how much you change these temperature readings to the ECU is uncertain. The optimal temp readings are based on the individual vehicle, the hydroxy system efficiency and amount, and countless other parameters. Tuning them is more like a black art than an exact science, but it is done similarly in all cars until the "sweet spots" are found. By this point it should be easy to understand the difficulty encountered here.
Last but not least, when you get the timing set right and your combustion is optimized you can safely reduce even more fuel and get even more than a typical 5-20% increase in mileage. Many people also don't realize that excess fuel is injected into an engine for other reasons, such as cooling the engine from the inside out and to prevent pooling, or lack of flamespread within the combustion chamber. If not enough fuel is sprayed on an intake stroke the combustion of the fuel that is added will result in parasitic losses within the engine stripping the away most of the useful power created by the stroke. The parasitic losses occur because the flame was not able to fully propagate across the air/fuel mixture and therefore not fully combust the fuel. By adding the hydroxy and making ignition improvements the leaner AFR will now burn effectively with low parasitic loss, better emissions, and plenty of power. Also, as long as the AFR is reasonably but not too intensely lean, the resulting water vapors from the hydroxy will cool the engine in place of the fuel that will be taken away. The trick is now getting the ECU to comply with a leaner AFR and keep it there. ECU's are programmed against maintaining a leaner AFR for all the reasons I brought up earlier in this writing regarding emissions, cat temps, and engine head temperature. Even if you successfully fool every sensor layer into producing this slightly leaner, hydroxy optimized AFR, there's been little success in overriding the ECU's protections for those parameters over an extended period of time. Thus, the MPG mirage! But don't give up!
-Mike
Sent: Fri 2/13/09 5:40 PM
To: Water4Gas@yahoogroups.com
OBDII systems were specifically designed first and foremost to regulate the emissions of our vehicles and to create a set standard by which all manufacturers could meet compliance for those modern emissions requirements, governed by the EPA. Most people don't realize that the most common factory set air to fuel ratio on our vehicles, 14.7:1, is set as a compromise between performance, economy, and emissions. The primary reason it is set there is for emissions purposes. It's to have enough left over fuel/hydrocarbons exiting the exhaust to heat the catalytic converter, as the cat cannot do it's job at breaking down hydrocarbons through catalysis unless it's up to its full operating temperature range, which happens to be between 600 and 1500 degrees F. So the whole modern combustion process is a catch-22. Even a modern internal combustion engine already has a limited efficiency by design before worrying about emissions, but because we need to limit emissions we waste even more fuel and operate at even lower efficiency by throwing more accelerant (unburned fuel) on the catalytic convertor to keep it hot. It's obvious that if you can stop the catch 22 and burn all the fuel in the engine without sending it out to the cat there's plenty of mileage to be gained there.
When any working fuel economy device is used it immediately begins to alter the content in the exhaust. A true increase in combustion efficiency will produce less emissions there. ( For any doubts about whether hydroxy or even less potent pure hydrogen gas has the ability to alter combustion efficiency consult the web published research of NASA, MIT, and the US D.O.T. ) Less emissions are immediately detected by the O2/AFR sensors if the reduction is dramatic enough. Since the ECU is programmed to maintain the temperature of the catalytic convertor and see the amount of oxygen relevant to the 14.7:1 AFR, the ECU will not allow alterations in economy. It will counter them by increasing the fuel injection rate so that the cat temps are maintained and the oxygen levels detected are nominal for 14.7:1. This is why injecting hydroxy while doing nothing else usually produces a negative effect on mileage. In a vicious circle the hydroxy improves the burn, the hydrocarbons are reduced, it's detected in the exhaust by the o2 sensors, and more fuel is added until the sensor parameters return to normal.
Hydroxy experimenters counter this by using an EFIE (Electronic Fuel Injection Enhancer). Dutchman uses their Optimizer3x. Basically what the devices do is make up for the loss of hydrocarbons in the exhaust electronically. A typical o2 sensor has an operating range of .1-1.2volts. .1 volts would be interpreted as lean and 1.2 volts would be rich. .5 volts represents the targeted 14.7:1 AFR. As the hydrocarbons go down in the exhaust the average voltage of the o2 sensor to the ECU also follows. An EFIE or Optimizer3x will add voltage to the o2 sensor to bring the average back up to around .5v and take away the ECU's ability to detect a difference in exhaust, however that is far from the end of the battle with the ECU. Most OBDII vehicles use downstream sensors, that is, o2 sensors located on the exhaust pipe after the catalytic converter, to monitor catalytic converter temps as well as hydrocarbon emissions.
So lets say you're running hydroxy, combustion efficiency is increased, the exhausted hydrocarbons go down, and you've successfully returned the o2 sensor's readings to average .5 volts with an EFIE. Without those hydrocarbons heating up the catalytic convertor to operating temperature another alarm goes off in the ECU because cat temps have dropped dramatically, and fuel is once again added to balance the equation. Can you begin to see how difficult this is to get working? Not to mention that EFIE design leaves much to be desired, because it's impossible to set one voltage offset for added voltage and have it be correct in all environmental variables and driving conditions. The only correct way to do this would be to use the incoming o2 sensor signal and other ECU parameters such as ambient temp, or ambient MAP pressure as a reference to determine the proper voltage offset to equal a simulated 14.7:1 for the ECU all the time. Unfortunately I don't know of anyone that has invented such a device.
What I've written here is just the tip of the iceberg of what experimenters are trying to do with our modifications. There's much more. With the increase in flame propagation speed within the combustion chamber provided by added hydroxy, the stock ignition timing is not optimal for both performance and for emissions. There's greater mileage, performance, and a reduction of emissions to be gained by retarding the ignition timing to optimize the combustion further. In the old days you could alter this with just a turn of the distributor cap and a timing light, but these days on most cars the ECU automatically determines engine timing, mostly based on the IAT (Intake Air Temp) sensor. To deal with this we add resistance in parallel with the sensor and alter voltages to the ECU. Higher perceived temps for the ECU will retard timing, and that is what is simulated, but the IAT temp can't be the only one that's seen high or the ECU will not accept it, and a check engine light will illuminate. If the coolant temp also appears higher the ECU will comply with the changing of the timing without hesitation, so the same parallel resistance technique is applied to the CTS sensor. Just how much you change these temperature readings to the ECU is uncertain. The optimal temp readings are based on the individual vehicle, the hydroxy system efficiency and amount, and countless other parameters. Tuning them is more like a black art than an exact science, but it is done similarly in all cars until the "sweet spots" are found. By this point it should be easy to understand the difficulty encountered here.
Last but not least, when you get the timing set right and your combustion is optimized you can safely reduce even more fuel and get even more than a typical 5-20% increase in mileage. Many people also don't realize that excess fuel is injected into an engine for other reasons, such as cooling the engine from the inside out and to prevent pooling, or lack of flamespread within the combustion chamber. If not enough fuel is sprayed on an intake stroke the combustion of the fuel that is added will result in parasitic losses within the engine stripping the away most of the useful power created by the stroke. The parasitic losses occur because the flame was not able to fully propagate across the air/fuel mixture and therefore not fully combust the fuel. By adding the hydroxy and making ignition improvements the leaner AFR will now burn effectively with low parasitic loss, better emissions, and plenty of power. Also, as long as the AFR is reasonably but not too intensely lean, the resulting water vapors from the hydroxy will cool the engine in place of the fuel that will be taken away. The trick is now getting the ECU to comply with a leaner AFR and keep it there. ECU's are programmed against maintaining a leaner AFR for all the reasons I brought up earlier in this writing regarding emissions, cat temps, and engine head temperature. Even if you successfully fool every sensor layer into producing this slightly leaner, hydroxy optimized AFR, there's been little success in overriding the ECU's protections for those parameters over an extended period of time. Thus, the MPG mirage! But don't give up!
-Mike