James Kovach
12-27-2009, 06:41 PM
So far I have flown the Radikal with the 6.0 and 6.4 gear ratios. I have been loggin in flight RPM and Engine Temps to find the "sweet" spot of the stock Zenoah G20. Here are my findings so far.
The first graph is about the engine temps. I lost the data for the other flight that I will be referring to, but you will get the picture. Notice during that flight how the temps are staying pretty consistent no matter how loaded the head is. That particular flight was with the 6.4 ratio at 1900ish RPM. I had another flight logged, which I lost the files for, that was on the 6.4 gears at 2050ish rpm. On that particular flight, the engine temps were even more consistent. This tells me that the engine is "happiest" running at that particular engine RPM, 2050*6.4=13,120. So that is probably a good "target" rpm for the engine.
The second graph is RPM logs from 3 different flights as follows:
- 6.0 gears at 1900ish RPM
- 6.4 gears at 2050ish RPM
- 6.4 gears at 1900ish RPM
The thing you will notice is not matter what I have my limiter set to, when the head is loaded during flight, they will all fall into the same RPM range and stay there. The only time it will go back up to a higher RPM is when the head is unloaded. So looking at the graph, it seems that 1800-1900 RPM is going to the max this engine can sustain when loaded. I know it is falling below that in the graph, but I have not flown the 6.9 gears yet, so I am making a little bit of an assumption.
What you cannot see that well in the graph because it is pretty cluttered is how the RPM recovered after being loaded. The 6.4 ratio definitely recovers quicker. I suspect that the 6.9s are going to be even better as you will be able to run the 1800-1900 rpm with the engine being up in the Higher 12k to lower 13k range. I fully expect that when I get to loggin the 6.9 gears, you are not going to see it fall off the target RPM as much and when it does it will recover very quickly.
I will post more info when I get a chance to fly the 6.9 gears.
The first graph is about the engine temps. I lost the data for the other flight that I will be referring to, but you will get the picture. Notice during that flight how the temps are staying pretty consistent no matter how loaded the head is. That particular flight was with the 6.4 ratio at 1900ish RPM. I had another flight logged, which I lost the files for, that was on the 6.4 gears at 2050ish rpm. On that particular flight, the engine temps were even more consistent. This tells me that the engine is "happiest" running at that particular engine RPM, 2050*6.4=13,120. So that is probably a good "target" rpm for the engine.
The second graph is RPM logs from 3 different flights as follows:
- 6.0 gears at 1900ish RPM
- 6.4 gears at 2050ish RPM
- 6.4 gears at 1900ish RPM
The thing you will notice is not matter what I have my limiter set to, when the head is loaded during flight, they will all fall into the same RPM range and stay there. The only time it will go back up to a higher RPM is when the head is unloaded. So looking at the graph, it seems that 1800-1900 RPM is going to the max this engine can sustain when loaded. I know it is falling below that in the graph, but I have not flown the 6.9 gears yet, so I am making a little bit of an assumption.
What you cannot see that well in the graph because it is pretty cluttered is how the RPM recovered after being loaded. The 6.4 ratio definitely recovers quicker. I suspect that the 6.9s are going to be even better as you will be able to run the 1800-1900 rpm with the engine being up in the Higher 12k to lower 13k range. I fully expect that when I get to loggin the 6.9 gears, you are not going to see it fall off the target RPM as much and when it does it will recover very quickly.
I will post more info when I get a chance to fly the 6.9 gears.