V8 Engine Conversion
Problem: Converting a Turbo V8 Engine to a Supercharged V8. However, the Throttle Plate Was Vibrating Due to Increased Airflow from the Supercharger.
The client was making improvements to a computer controlled internal combustion engine system. The throttle was not mechanically connected to the operator's control (foot pedal). It was a computer-controlled, throttle-by-wire system (no mechanical link). The engine improvements caused the throttle plate to vibrate at high power levels sending spurious signals to the control computer which caused it to shut down the engine.
An electronic filter in the throttle signal path to the computer introduced enough uncompensated lag in the control loop to shut the system down. There were two possible solutions.
The engine control computer could, possibly be re-programmed to incorporate or accommodate the filter.
Mechanically eliminate the vibration.
Because I determined that the control computer could not be reprogrammed due to an inability to obtain appropriate tools outside the manufacturer, and the client had mechanical expertise, I went with solution #2. The throttle plate was driven by a servo motor through a 5-to-1 spur gear set (40 teeth to 8 teeth) with a maximum motor speed of 600 RPM. The system was altered by replacing the 40-to-8 spur gear set with a 40-tooth worm gear driven system and motor with a maximum speed of 4800 RPM.