Re: [A/S] BD chip for Diesel Power Stroke

["Tom Patterson" <tom@xxxxxxxxxxxxxxxx>]

Bill,
    
     You ask tough questions for this poor retired accountant.  I really don't know the answer, but suspect that the answer is mainly mix of air and fuel.  There may be some change in the timing of the shift in gears, and maybe something to do with the injection of the fuel, which I understand is fairly complex too, as I think there is a pre-injection, as well as the injection involved.
     Diesel motors differ from gas though, in that you control the speed of a gas engine by varying the amount of air.  The mixture is a constant 14 parts of air to 1 part of fuel, I understand.  Diesel engine speed is controlled by varying the amount of fuel.  The mix varies from 20 parts of air to 1 part of fuel while working, all the way to 80 parts of air and 1 part fuel while idling.  This mix is part of the reason why diesel motors are more efficient than gas, and is why diesel motors don't use a lot of fuel while they are idling.  Diesel fuel also has a higher BTU value than does gasoline.  It also seems to me that the mix must be the main item controlled by the chip as this is such a variable anyway.
     Also, when you do use more fuel, as when the engine is working, naturally the heat that is released increases.  This is where your pyrometer, (exhaust gas temperature meter) comes into play.  This meter effectively measures this heat, and allows you to ensure that you don't damage your engine, and also, allows you to control the heat, by doing such things as taking your foot off the gas pedal, or by changing gears.  I am told that the optimum gas mileage is achieved when the exhaust gas temperature is about 600 degrees, so I guess that is what you aim for.  Now, probably the chip is in there working to this objective too.  
     What we need is someone with more knowledge to expand on this, or offer a better explanation.
    
-Tom
mailto:tom@tompatterson.com 
Website: http://www.tompatterson.com