Getting Started in GSR, A Rookie's Perspective

[joeraf]

Converting the airframe from gas to alcohol is fairly simple. No major structural modifications are needed. The fuel system is replaced with one that is methanol compatible. Fuel capacity has to be increased. The single 24 oz tank used with the gas engine was replaced by a 40 oz main / 10 oz header tank. Main tank placement is not critical however the header should be positioned close to the engine and on plane with the fuel inlet. Mixture control needles should be mounted so as to minimize excess fuel line length between the needles and inlets.


F1 propellers have a different profile from the GT prop. The spinner cutout had to be modified.


Matched cylinder temperatures are important in that temp differential causes a loss of rpm's. With the ability to adjust individual cylinder fuel mixtures, and control cooling duct airflow, I thought it was important to know exactly how the engine was performing in flight. A lot of the guys install data loggers in their planes.. These record down loadable data and can help maximize engine performance. Two of these systems are from RCATS http://rcatsystems.com/telemetry/telemetry_rc.php and Eagle Tree http://www.eagletreesystems.com/Plane/plane.html. These systems also have telemetry available.


I installed the Eagle Tree system and measure rpm, cylinder head temps and exhaust gas temps. Since I have not had much running time in F1, I downloaded data after each heat and was able to make small beneficial adjustments between the heats.


Lastly, I had to rebalance the plane due to the weight saving modifications and the weight differential between the two engines.

[joeraf]

Ashtabula was the next race in the series and the team was in better shape having no overlap in the classes and well tested airplanes. Check in, tech inspections and practice were becoming routine. As I was setting up the plane Fred French, who modified the engine, checked the installation and tweaked the mixture controls. He gave me some pointers on the best way to set the mixtures during a race. Very helpful.


There was very little difference that I could tell between flying in the GT and F1 classes. I had to concentrate on controlling the torque on takeoff by feeding in much more rudder than the GT powered plane. While top speeds differ by 30 or 40 mph and lap times are lower, I never felt overwhelmed by this. I think that
the speed becomes secondary to racing. Timing the turns is a little different, and you have to pay attention to how the engine is performing.


I learned that consistency in F1 is the key to placing high in the standings. Not consistent as in being fast, but consistent as in finishing the heat. Out of the five heats that I flew, I DNF'd two of them. The first DNF happened because I failed to clear the engine out prior to takeoff and it quit on rotation. The second was during the gold race when I got too aggressive with the mixture, leaning the engine too much and burning it down. It seemed that most of the F1 heats had one or two planes that had trouble finishing.


I also learned not to become too attached to your airplane in GSR. The mid-air collision festival seemed to start in Ashtabula this year apparently continuing at Parker, and one of the planes involved was Robert's. This changed the team's plans pretty drastically as he had no backup for the last race in Parker. We decided that the 4000 mile round trip wouldn't be worth it with just one flyable plane.


Robert Vess photo



That's it for my first year experience. I hope that I've provided a little insight into what it took for me to get started in GSR.

[timlime]

THOSE ARE SOME SWEET FLAMES!