Volumetric Efficiency ???
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From: Blue Springs, MO
Volumetric Efficiency ???
Does anybody know the volumetric efficiency of the 7.3 PSD?
I have a '99 E-350 cargo van with the towing package. The only modification that I know of is the valve cover breather tube to the air intake has been rerouted to the ground.
I have a lap top based scan tool and am trying to use it to calculate instant fuel mileage but need to know the volumetric efficiency. The default 65% that the program puts in is giving me 4-5 mpg average and trip fuel mileage. However, the tank/odometer math says it is closer to 12-14 mpg.
I have a '99 E-350 cargo van with the towing package. The only modification that I know of is the valve cover breather tube to the air intake has been rerouted to the ground.
I have a lap top based scan tool and am trying to use it to calculate instant fuel mileage but need to know the volumetric efficiency. The default 65% that the program puts in is giving me 4-5 mpg average and trip fuel mileage. However, the tank/odometer math says it is closer to 12-14 mpg.
Post Fiend
Joined: Sep 2003
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From: Mesa AZ
Does anybody know the volumetric efficiency of the 7.3 PSD?
I have a '99 E-350 cargo van with the towing package. The only modification that I know of is the valve cover breather tube to the air intake has been rerouted to the ground.
I have a lap top based scan tool and am trying to use it to calculate instant fuel mileage but need to know the volumetric efficiency. The default 65% that the program puts in is giving me 4-5 mpg average and trip fuel mileage. However, the tank/odometer math says it is closer to 12-14 mpg.
I have a '99 E-350 cargo van with the towing package. The only modification that I know of is the valve cover breather tube to the air intake has been rerouted to the ground.
I have a lap top based scan tool and am trying to use it to calculate instant fuel mileage but need to know the volumetric efficiency. The default 65% that the program puts in is giving me 4-5 mpg average and trip fuel mileage. However, the tank/odometer math says it is closer to 12-14 mpg.
From what I remember, VE is a ratio between how much air volume the engine draws in compared to the actual volume needed to fill the cylinder. Although, it's been a long long time since my drag strip days so things could have changed since I was into all that stuff.
Your laptop program might be attempting to calculate fuel mileage based on the VE ratio of an air/fuel mixture which might not work in your case because the 7.3 Power Stroke is direct injected. So, your program might not work even if you knew the VE of a non-turbo 7.3 and corrected for your boost level. For a direct injected engine, the value you want is "Volume Fuel Desired". Is your scan tool able to determine that value? I have AutoEnginuity and it shows that value but I don't how it comes up with it. I suppose it's a calculated value based on fuel pulse width and some sort of constant base line value for fuel pressure.
Frmr Ford Trans Engr
Joined: Aug 1999
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From: SE Florida
VE applies to all engines. The figure will be above 1.0 when there is boost in the intake manifold. 2 PSI will get you right around 1.0 as a ballpark figure.
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From: Blue Springs, MO
Thank you
Thank you all for your input. I'm bumping this topic to get more input. I'm planning on taking a trip this week. I will be pulling my 35 foot travel trailer from Kansas City to central Florida. What would be a good average VE to plug into the scan tool for the trip?
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From: Blue Springs, MO
I understand that the VE will vary.
I'm just looking for a rough estimated average so that when I fill up and do the math and see that I'm getting "X" MPG that my scan tool is saying that my "average" fuel milage is about the same as "X".
At 65% VE my scan tool was giving me abt 4-5 MPG.
At 100% VE my scantool is giving me abt 3 MPG.
Not the direction I thought it would go.
I'm just looking for a rough estimated average so that when I fill up and do the math and see that I'm getting "X" MPG that my scan tool is saying that my "average" fuel milage is about the same as "X".
At 65% VE my scan tool was giving me abt 4-5 MPG.
At 100% VE my scantool is giving me abt 3 MPG.
Not the direction I thought it would go.
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