Improving the performance of two-stroke motorcycle with tuned adjustable exhaust pipe
Research Journal of Applied Sciences, Engineering and Technology
Department of Mechanical Engineering, Ambrose Alli University, Ekpoma Edo State, Nigeria
Engine performance is strongly dependent on gas dynamic phenomena in intake and exhaust systems. Careful design of the manifolds enables the engineer to manipulate the characteristics. The basic exhaust tuning mechanisms was described w ith respect to a two-stroke single-cylinder engine. Tuned adjustable exhaust pipe for use on two-stroke motorcycle was designed and tested. The dynamometer used incorporated a flywheel of appropriate moment of inertia to simulate the mass of the motorcycle and rider. The test procedure involved measurement of the flywheel speed during an acceleration phase resulting from opening the throttle. Calculation of the instantaneous flywheel acceleration gave a measure of the torque and power characteristics. The airflow based values of delivery ratio; trapping efficiency and charging efficiency were not measured directly but were culled from the fuel flow values and the Spindt computation of the exhaust gas analysis. Experimental test results were presented for power output, specific fuel consumption and engine-out emissions. The tuned exhaust system was found to improve fuel economy of the engine by 12%. The major engine-out emissions, HC and CO were reduced by a minimum of 27.8% and 10.7% respectively. An improved power output of 15.8% increase was achieved. As a bonus, it w as also found that the exhaust noise was reduced. © Maxwell Scientific Organization, 2009.
Acceleration phase; Charging efficiency; Delivery ratio; Dynamic phenomena; Engine performance; Engine-out emissions; Exhaust noise; Exhaust pipes; Exhaust systems; Experimental test; Fuel flow; Gas analysis; Intake and exhaust; Moment of inertia; Performance characteristics; Power characteristic; Power out put; Single-cylinder engines; Specific fuel consumption; Test procedures; Trapping efficiencies; Tuned exhaust pipe; Tuning mechanism; Engine cylinders; Flywheels; Fuel economy; Fuels; Gas fuel analysis; Machine design; Motorcycles; Pipe; Testing; Wheels; Exhaust systems (engine)