Your Accord May Have Turbocharger Lag

A turbocharger works by compressing the air entering  an engine allowing the combustion chamber to be overfilled without going to larger cylinders. You may have one on your Honda. If you do it there is a good chance it was an aftermarket installation.  

Inside a turbo are two key devices. One is a turbine and the other is a compressor.  Driving the turbocharger is the exhaust gasses from  the engine. The exhaust gases spin the turbine wihich is usually on the same shaft as the compressor. The compressor then compresses the incoming air and it is routed to the engine. In most cases because this compressed air is very hot, its path is through some type of cooler or inter-cooler.

Being powered by exhaust gas is a key differences between a turbocharger and a supercharger. A supercharger is driven directly from the engine via a belt or gearing.

A typical turbocharger has two different built in delays before coming up to full operating speed.

•   The first is called Turbo-Spool, where there is a delay from low revolutions, because of the lack of enough exhaust gas flow, or not enough pressure to start the turbine spinning. Often this turbo spin delay in the turbocharger is called  turbo lag. However this is incorrect.

•  Once the turbine has started spinning, there is a fast increase in the power available. As the turbocharger turns faster it produces more boost and power which  results in more exhaust gas being produced by the engine. The turbine therefore spins faster (they can spin at 150,000 rpm) and in turn causes a surge of acceleration.

•   Turbo-lag from a turbocharger  is the delay time it takes in spinning the turbo up where there is enough engine speed to create boost and reach full operating speed. Some turbochargers do not produce their maximum boost until high rpms, which means that there is more lag. Others will produce less boost at lower rpms and therefore have very little lag time.

•   One of the ways to improving or really decreasing this lag time is with a careful match the turbocharger with its ultimate use. A modern turbocharger will have eliminated a great deal of the turbocharger  lag delay times seen in older models, because of newer designs and materials.

•   One approach, being used  today, to reduce turbocharger lag is the use of two smaller turbocharger, instead of the older and larger style turbocharger. This is usually called a twin-turbo, if both of these are of the same size. Using two smaller turbocharger will result in more power output than one larger one of the same output capacity. Each of the smaller turbos  have less rotating mass. Which means that the compressor can spin up to correct speed much faster. This is important in reducing the lag time. A second reason for choosing a twin-turbo  application is an increase in the exhaust outlet area, since each turbo receives exhaust gas flows. This increase allows for more exhaust gas to flow than in a single turbo system. This increased  flow from the turbocharger will usually increase power.

Accord Turbocharger