Design and implementation of an exhaust system for a Citroen 2CV race car

摘要

This paper gives an overview of the design and production methods for a custom-made exhaust system for a Citroen 2CV race car. The goal of this new design is to improve the performance, especially the torque figures, at the critical shift points while maintaining a limited noise production. The design phase is done with simulations using ngspice software, where physical entities are represented by electrical ones. This electrical analogy included the exhaust tubes with variable lengths and the entire rotating engine with its intake manifold, combustion, crankshaft and camshaft profiles. After the simulations are done, the results are converted back from electrical to physical entities. The design resulted in a 30% increase in engine torque in the critical region where the engine operates in racing conditions. Equally important as the torque figures was the exhaust's noise production, which had to be limited to 95 decibels.