Is anyone running Megasquirt on something other than gasoline or diesel? Perhaps Propane or CNG?
Would a standard wideband O2 sensor work with such fuels or would a special one need to be sourced?
Megasquirt on Alternative fuel?
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efahl
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Another reason to stop using AFR...
Yes, the stoichiometric ratio of air to propane is 15.7:1, but that doesn't mean you should tune a WB to 15.7:1 to get stoich, since the WB display is calibrated for gasoline. A WB controller is programmed to produce some output voltage (say 2.5v) at lambda of 1.0. This corresponds to both 14.7:1 and 15.7:1, depending on what fuel you are burning (could also mean 6.45:1 with methanol). Read Bruce's comments about WB calibration on the E85 thread for info about non-stoich measurements using a WB.
My suggestion for anyone considering using any fuels other than gasoline is to start thinking in terms of lambda, which will allow you to compare mixture strengths without conversions, just like using kPa instead of psig and in-Hg.
Eric
Yes, the stoichiometric ratio of air to propane is 15.7:1, but that doesn't mean you should tune a WB to 15.7:1 to get stoich, since the WB display is calibrated for gasoline. A WB controller is programmed to produce some output voltage (say 2.5v) at lambda of 1.0. This corresponds to both 14.7:1 and 15.7:1, depending on what fuel you are burning (could also mean 6.45:1 with methanol). Read Bruce's comments about WB calibration on the E85 thread for info about non-stoich measurements using a WB.
My suggestion for anyone considering using any fuels other than gasoline is to start thinking in terms of lambda, which will allow you to compare mixture strengths without conversions, just like using kPa instead of psig and in-Hg.
Eric
Eric, Is there any info on lambda tuning? I am about to do some CNG work, gasoline and Diesel and would like to go at it in the right frame of mind.
Stoich is about 17.1:1 for CNG right?
Also, what does anyone know about sizing injectors for CNG?
Thanks,
Tony
Stoich is about 17.1:1 for CNG right?
Also, what does anyone know about sizing injectors for CNG?
Thanks,
Tony
Anthony R
75 Cosworth Vega turbo (MSII with EDIS)
91 Toyota Pickup, Auto(modified valve body), 22re 4cyl, 11:1 comp, cam, header, Fuel and VAST ignitor with o29y3
1968 Electric Subaru Sambar 360 VAN
'92 Biodiesel Jetta
75 Cosworth Vega turbo (MSII with EDIS)
91 Toyota Pickup, Auto(modified valve body), 22re 4cyl, 11:1 comp, cam, header, Fuel and VAST ignitor with o29y3
1968 Electric Subaru Sambar 360 VAN
'92 Biodiesel Jetta