Marc Holcomb, a retired Hughes Aircraft engineer, has developed a supercharger for the popular Jabiru 3300A engine. While the stock 3300 develops about 120 hp takeoff power, the supercharger boosts takeoff hp to 141. However, the real benefit comes in at the system’s sweet spot, between 8,000 and 12,000 feet of altitude. At 10,000 feet, the turbo-normalized supercharged engine is pumping out 114 hp, as opposed to the 80 hp of the normally aspirated 3300.
The secret sauce of this supercharger lies in the computer controlled boost regulator. Marc wrote the software for an Arduino computer that automatically controls the waste gate, keeping boost in check at low altitudes and keeping it steady at higher altitudes.
Marc has used his Arion Lightning as the test bed for his new supercharger. The entire drive unit and boost regulator fits snugly behind the engine, requiring no modification to the test aircraft’s engine mount. At this point, he has recorded a cruise of 172 mph at 10,000 feet, a 20% increase over the normally aspirated ship.
Experimentation continues. Marc has even more boost to give, but the current prop cannot keep up. Using data from his Airmaster electrically controlled constant speed prop, he is working with Airmaster to see if more prop will better harness the increased power. Marc will also be strapping on an oxygen mask to see how high the Lightning will climb with its efficiently controlled boost.
Once testing is completed, the supercharger will be marketed through Geronimo Experimental Aircraft of Mariana, Arizona. You can find more information at geronimoeabc.com.