THE TURBO LAG:
The turbo lag is a sluggish response from an automotive motor ,wherein below a certain RPM one experiences a delay- from the time the car is throttled and the time the engine responds to the accelerator input.It's a serious issue for an motor and engineers all over the world are trying to eradicate it.
This actually affects the city drivability the most as one needs to frequently work the gears in order to maintain a certain RPM level in a car.So, as the engine RPM rises the turbocharger also starts to spin faster and only after it has attained a certain RPM
you start to feel that sudden rush of torque.Therefore in a car engine where there's an issue of turbo lag the throttle responses won't follow a linear curve because the power surges up only after a certain RPM level is maintained.
(THIS IS A SERIOUS ASPECT THAT THE CAR BUYERS SHOULD KEEP INTO MIND BECAUSE IT IS A TREMENDOUS DRAWBACK FOR A VEHICLE AND CAN BE SERIOUSLY ANNOYING AT TIMES.)
Earlier in my article on TURBO CHARGED ENGINES I had already highlighted the working of a turbo charged engine.So, in order to brief-up how a turbo works by using the exhaust air to spin a turbine which is mounted on the same shaft as that of a compressor.The compressed air is then fed into the engine.This helps to maximize the power output for a given engine size.The turbine pumps in more air and hence more fuel into the combustion chamber than that of the normal atmospheric pressure.Therefore the turbo chargers depends on the pressure of the exhaust gases and needs a short time to build up this pressure(specially when then motor is revving at low rpms).So one needs to work the gears quite frequently in order to supply the engine with required RPM input.
This issue though not fully nullified but has been curbed to a great extent with the concept of VARIABLE GEOMETRY TURBO which would be discussed later.
