Resonant Intake and Variable Geometry Turbocharging Systems for a V8 Diesel Engine

A mathematical model is used to analyse the performance of conventional and resonant (Cser type) intake systems on turbocharged six-cylinder and V8 engines. For the V8 the system is slightly less effective than for the six, but is more compact and easily installed within the V of the engine. An optimum system was designed and tested on a V8 engine, with maximum torque b.m.e.p. increasing from 12.0 bar at 1850 rev/min to 12.7 bar at a reduced speed of 1600 rev/min.

Engine performance with the resonant system is compared to that with a simple variable-geometry turbocharger turbine, having only one major moving part. A mass-flowrate turndown of 42 per cent was achieved, but with a loss of turbine efficiency largely due to the constraints of adapting an existing turbocharger design. However a flat boost pressure curve was achieved from 1800–2600 rev/min. Maximum torque b.m.e.p. (with conventional inlet manifold) increased to 14 bar at 1600 rev/min. Engine performance at maximum speed (2600 rev/min) was unaffected with either system.