On a governed electric, take of rpm is the flight rpm.

Hey Chris, that's not exactly true with the KR timer/governor unless the gain value is set to 1.  If the gain is set higher than 1 then the flight RPM will be dependent on the difference between the level fight RPM and the RPM under load. 

If the RPM (for sake of discussion) drops 50 RPM when the nose is pulled up then the KR timer/governor will take the 50 RPM and multiply it by the gain value say 4 (which is where I fly) and add back in 200 RPM.  The amount of add-in will very with the load RPM, when the motor unloads (going down hill on a wingover) the revs drops back to level flight RPM the governor will hold the RPM to level flight (launch RPM).

This is why I do not compare KR Vari-gain to the old "4-2 break", the add-in come in proportional to the load increases and goes away proportionally as the load is removed.   It is almost impossible to hear the change in RPM but I have done extensive testing and proved it is working.
Andy

Some years ago, when I was playing with stunt diesels, I made myself an audio tach. It was just a simple buzzer type where you tune into the engine sound inside the circle. The output of the old 555 type timer chip went to the speaker and also an LED that you could read with a standard optical tach. I found that the increase in rpm all depends on how much torque the engine has. For example a standard FP .40 or Tower Hobbies .40 on a muffler would increase by 1500 rpm in the air. While a .40 VF on a pipe would gain about 1200. The same Tower .40 on diesel however, would only gain 500 rpm. I did not do a lot of testing on tuned pipes but I would guess that it all depends on how you set the needle. If your going a bit leaner and trying to get more of a constant rpm, I would think that the rpm increase would be less than the 1200 I measured. I did not at the time try any 4-strokes. The sounds is not as easy to "tune" into, but I would also guess that the rpm increase is a lot lower than a 2-stroke glow engine.

Electric on the other is "tuneable" to almost anything you desire. Igor's active regulation system with accelerometer can gain 1000 rpm in a climb and back-off by 1000 rpm in a dive. A good tuned pipe system when it's on song, can do the same. I remember having a chat to Gilbert Beringer at the 2004 world champs in Muncie, where he was using a twin 4-stroke stunter. He said that he had done a great deal of experimenting with 2/4 break systems, and preferred a more constant rpm in turbulence because it was just more predictable. He found that diesels worked very well, but he didn't like the pong, so ended up with 4-bangers. In good stunt weather most systems work well, and also in consistent wind, but turbulence is the problem. I don't want to speak for Igor, but I do know that this was one of the challenges he had to overcome when he developed his present active regulation system. In Bulgaria, we had loads of turbulence, even in low wind, and his system sure worked well for him and quite a few others as well. In comparing my own governor timer system to my diesels I would say that they are as good or better.....without the pong and gunk! With the extra gain boost, they are definitely better.

Keith R

Amen on the pong.

My wife totally agrees with you Howard!