Nice thread here.
Woody, respectfully… I think the duty cycle in 5th gear is going the other way… the RPM drop is causing the engine to stoke the gasifier less, resulting in a drop in production, or a lower duty cycle. The engine RPM seems to be one of the keys to the ultimate output you can get from a gasifier… Could your truck drive the duty cycle to 100% in 4th if not for redline of the engine (the air pump driving the gasifier).
I am glad to see everyone taking notes and making measurements in a uniform way to help gauge WG performance. The HP calculator is spitting out an average HP for the 0-60 run. I think that the aerodynamic drag increases exponentially, so that is why the HP needs increase at higher speeds. I like the time measurement and calculator as a tool, or indicator, or point of reference, so…
I decided I would try something in my gasoline powered Dakota to (since I don’t Drive on Wood (yet)). The plan is to compare a gearing change on a gasoline engine to see if there is a difference in the average HP stated by the calculator. We all know there has been no engine or fuel modification, but would there be a resulting difference in HP ?
My 4x4 Dakota has a dual range transfer case, 4 low and 4 high. I had planned to do a 0-60 pass in 4 high as a baseline, and then make another 0-60 pass using 4 low, then plug the numbers into the calculator. However, there may be an issue with my 4 low, because the light blinks when I switch it to 4 low. (is this normal?) It pulls like the lower gear set is working, but I am not ready to throw caution to the wind and tach it out in 4 low if there may be a problem…The other thing is I think the owners manual and common sense sez to keep it below highway speeds in 4 low. Anyone ever drive 60 using 4 low ? I could look for a 0-40 MPH calculator alternatively…
The point I am trying to prove (or dis-prove) is that a vehicle with the same engine, and same fuel, but with different gears may get you different times in the 0-60, and could result in a different average HP in the calculator… I do not know enough about it to say how much difference, but would imagine the lower gears will give you higher HP numbers unless the engine cannot rev high enough because of some other limitation like exceeding the redline trying to get to 60 in top gear…
I am also curious about the chicken and egg aspect of the engine driving the gasifier to make the fuel for the engine to spin faster to make the gasifier work harder to make more fuel…Once this has been repeated up to the top speed (100% of output) is the system limited by the speed of burning so much wood at a time or something like n pounds per minute? Is this where there is a concern of overheating the unit, or is it when the gasifier is running low on fuel, or both ?