Towards zero turbolag engines

The paper identifies the contributors to turbolag in the engine turbocharging system. A literature review records improvements to turbocharger design - its turbine, compressor, housings and bearings, and auxiliary systems which can improve transient performance. Areas in engine design which can be optimised to improve low speed torque, and hence reduce turbolag, include port and manifold designs, cam timing and fuel and ignition control systems. In a case study of a 1.3 Litre turbocharged engine, almost identical vehicle performance with that of a 2 litre normally aspirated counterpart is demonstrated. However, evidence of the turbocharger's presence can still be demonstrated at very low engine speeds. This penalty is offset by significant fuel savings (a).