Crew Report - 13 Mar 14
March 18, 2014 at 1:51 PM
In the last report I said we would have some valid dyno information about the standard 640 HP Falconer engines most TM owners have. The dyno work was done at Exotic Engines here in Reno and they specialize in Viper V-10s, so a V-12 was not far from their area of expertise. Their engine tuners and I spent two days tuning my 640 HP engine which uses the MoTeC M600 ECUs. I spent a lot of time making small changes then testing the results after each change. The results of maximum HP test, corrected for sea level, can be seen below.
In conclusion, I can say the engine ran quite strong and smooth. The fuel and ignition maps look quite reasonable. As you can see in the dyno results on the next page that the HP peak is between 4500 and 4700 RPM and is quite fuel efficient at .43 BSFC. The Brake Mean Effective Pressure (BMEP) is of little value other than to compare one engine type against another and gives the engine builder some idea of the load on the pistons, pins, rods and must bear. The BMEP for our engines of +/- 200 PSI is a relatively high number compared to Lycomings or Continentals.
I tried to simulate some cruise conditions at eleven to twelve thousand feet but due to the limitations of the dyno and the equipment I had to simulate these conditions, I was unable to establish a stable condition. The MAP and RPM would vary up and down with resulting variations in HP and FF. The cruise condition I was attempting to obtain was 4000 RPM, WOT and 20” MAP. I could only try to read the data as the engine was passing through the desired condition. The result of what I could come up with at the desired condition was that the engine would develop 390+/- HP at 4000 RPM @ 20” Map with a FF of 28.8+/- GPH. Leaning the mixture with the trim switch 8 – 10% would probably increase the specific range by a considerable amount.
I am not sure what the value of the above chart is to most TM owners , but the value to me is to know just what the HP really is. The real value that justifies the time, effort and expense of this dyno work is to know that I now have a valid fuel and ignition map for the ECUs.
The new ECU program will be available to all TM owners from AAR. Our program will require that the aircraft have both barometric and manifold pressure sensors and a fuel trim switch which we can install here at the AAR facility.
Our next event is the Mojave Fly-In April 19 & 20 where some of our competitors and friends will be attempting some national speed records. The Blue Crew will be there to see how they do and wish them well.
The Blue Thunder Team and I want to thank everyone for their continued support and hope all have a Happy Easter.
For the Blue Thunder Team, I am John Parker