On the Use of a Honda 600cc 4-Cylinder Engine for Formula SAE Competition 2005-01-0025

The Formula SAE® rules require the use of a 20mm intake restrictor. The presence of the restrictor necessitates the design or retuning of fuel and spark strategies that, in turn require the use of a programmable engine control unit (ECU). This paper describes a process used to establish the fuel and spark strategies for a standard production motorcycle engine operating with a restricted air intake. Honda 600cc engines were controlled by three different ECUs: a Haltech, DTA and an “in-house” ECU. Simple calculations of injection duration are suggested to provide a baseline fuel map from which the engine could be started, and then fuel maps are tuned by experiment. Similar baseline numbers for ignition timing are given. Experimental dynamometer testing was performed to determine spark/fuel hooks, MBT timing and whether to inject onto open or closed intake valves. 1-D engine simulations were developed using both Wave® and GT-Power® to provide a simulation environment for the FSAE engine development. The 1-D models were validated with steady-state flow bench data and dynamometer tests.