What is Turbo Lag?
3 Answers
Turbo lag refers to the time required for the turbocharger's pressure to rise to its maximum value after the throttle is fully opened. It is a common phenomenon in turbocharged engines. The following is an introduction to turbo lag: 1. Turbocharging technology is a method to enhance an engine's air intake capacity. When you see 'turbo' or 't' on a car's rear, it indicates that the vehicle is equipped with a turbocharged engine. 2. The main function of a turbocharger is to increase the engine's air intake, thereby boosting the engine's power and torque, making the vehicle more powerful. 3. Turbocharging can be categorized into mechanical supercharging, pressure wave supercharging, exhaust gas turbocharging, and compound supercharging.
I really felt it the other day when I was driving my friend's turbocharged car. Turbo lag is that feeling where you press the accelerator and have to wait half a second to a second before the power kicks in. The principle is simple: the exhaust gases from the engine need to accumulate to a certain level to spin the turbine blades, and this time gap is the lag. It's most noticeable during low-speed, sudden acceleration, like when you're overtaking on the highway—you press the gas and have to mentally count '1, 2' before you feel the push. However, newer cars now use twin-scroll turbos, electric turbos, or 48V mild hybrid technology, which has significantly improved the lag. The driving experience is much closer to that of a naturally aspirated car.
From a mechanical principle perspective, turbo lag is essentially a time difference in energy conversion. Imagine exhaust gases needing to pass through the exhaust manifold to drive the turbine, which then powers the compressor to compress the intake air—the entire piping system acts like a 'clogged air path.' I've noticed that cars with slender exhaust pipes exhibit more pronounced lag because of higher exhaust flow resistance. Recently, I drove an Audi with VTG variable geometry turbocharging, where the turbine blade angle adjusts with RPM changes, achieving full boost below 2,000 rpm, making the lag sensation almost negligible.
