What Is Turbo Lag?

Turbocharger Lag Explained

Are you a car enthusiast? If you are, you must have heard of turbo lag. However, most people, including some motor enthusiasts, do not know what turbo lag is, what causes it and how you can prevent or minimise the occurrence of turbo lag. Not knowing what turbo lag is could be a disadvantage for most car enthusiasts or anyone who would like to buy a car, especially cars that allow you to initiate the turbo.

In this article, we will enlighten you with a summary of the most relevant and necessary information that you need to know about turbo lag. However, before getting right into turbo lag, what causes it, and how you can prevent or minimise its occurrence, it is essential to understand one other important factor closely related to turbo lag - the turbocharger.

What Is A Turbocharger?

A turbocharger is an engine component that increases the power output of a vehicle engine by driving more air into the vehicle engine. The turbo lag is more prevalent in diesel vehicles than gasoline vehicles. Depending on the car and what the driver desires, turbo lag could be relevant or a nuisance.

The operation of the turbocharging engine is as simple as inflating a balloon. You simply blow more air into the balloon, and the pressure exerted increases the volume of the air inside the balloon, making the balloon expand. The same applies to a turbocharger; when the turbocharger forces more air into the vehicle engine, it exerts pressure that creates a more significant bang in the engine, thus boosting the engine's overall output.‍

Exhaust gases power up the turbocharger. One side of the turbocharger takes up most of the exhaust gases while the remaining exhaust gases go to the exhaust system through the other side of the turbocharger to spool the turbine.

The intake turbine is connected to the exhaust turbine. As the exhaust turbine spins, the intake turbine also spins, pulling in more air into the vehicle's engine. This process leads more air into the engine, boosting the engine's horsepower.

Understanding Turbo Lag

Now that you already know what a turbocharger is and how it operates, dissecting the term turbo lag is essential. Turbo lag is specifically experienced when one drives a turbocharged vehicle. But what is turbo lag? Turbo lag refers to the period between when the throttle mashes and the moment when one feels the rush of the torque coming from the turbocharged engine.

The period mentioned above is basically the time the vehicle engine takes to create sufficient and adequate exhaust pressure to spin the turbo and push compressed intake air into the engine.

The duration of the turbo lag is different under various circumstances. It depends on varying factors such as the load cruising conditions and the vehicle engine's rpm (Revolutions Per Minute). When both the load cruising condition of the engine and rpm are low, the turbo lag will be quite long.

Can I Feel Turbo Lag?

What does turbo lag feel like? Can you detect when turbo lag is underway? The simple answer is yes. You can feel turbo lag whenever your foot is on the accelerator of a turbocharged vehicle, whether electric cars or hybrid cars. Your turbocharged vehicle will start to accelerate faster when the turbo reaches the spooling speed (this speed varies from vehicle to vehicle).

As it reaches the spooling up point, more fuel and air are forced into the engine, thus boosting the horsepower of the vehicle engine. Have you ever wondered why you cannot make a turbo that goes full boost up to the redline? A turbo's efficient and effective operation depends on the rpm range, a figure specific to every turbo.

There are different possible scenarios with turbos. If you have a large turbocharger that can make a lot of power, it may not make any boost until it settles into the powerband of the engine.

A small turbocharger that can boost horsepower substantially under low rpm situations is highly likely to over-speed. In extreme cases, the turbo may even explode immediately after hitting the throttle. These factors can also impact turbo lag significantly.

How To Reduce Turbo Lag

Low engine speed can cause turbo lag in turbocharged vehicles. When insufficient power is generated in the vehicle engine, there will not be enough exhaust gases to spool the turbine, causing a turbo lag. Car manufacturers use the following methods to minimise or reduce turbo lag in turbocharged vehicles:

Lighter materials for turbocharger framing

Manufacturers are now using lighter materials to significantly reduce turbo lag. This includes alloys, which are pretty strong but light enough to minimise air resistance and inertia. Lowering these two factors reduces turbo lagging, increasing turbocharger spooling.

Addition of a wastegate

A smaller exhaust housing is fitted onto the turbo to spool the turbo faster. In addition, an exhaust wastegate is fitted to get rid of the excess exhaust pressure when the engine rpm is high. You can fit between two and four exhaust wastegates on one turbo frame.

Increasing compression ratio

Traditionally, most turbocharged vehicles had a compression ratio of 8:1. Such an engine would have low compression and produce no power until the boost hit. Manufacturers have resorted to increasing the compression ratio for turbocharged vehicles to reduce turbo lag. Most turbocharged cars nowadays have a compression ratio of between 9:1 and 10:1.

Narrowing the powerband

A narrow powerband effectively reduces the turbo lag because turbochargers work best when they are able to supplement a constant airflow. Limiting the width of the band can reduce the turbo lag for large displacement engines. This is because it will be easier to maintain peak power production throughout a narrow band.

Improving turbo designs

Another way to reduce turbo lag is to find new ways to improve the design of turbo components to increase their performance, efficiency, and responsiveness. Improving components such as the bearings, compressors, and turbines can help reduce inertia and friction, lowering turbo lag.

Addition of nitrous oxide

Adding reasonable amounts of nitrous oxide to the engine could also help reduce turbo lag. Nitrous oxide creates a lot of pressure in the engine, causing a lot of exhaust to be pushed out with great force. The pressure will spool the turbo quickly, and you will immediately feel the effects. Nitrous oxide can reduce lag time by a factor of four.

However, you should be very cautious with the amount of nitrous oxide you add so as not to interfere with the ratio of the fuel to the air. If you don't adjust the fuel or air ratio after adding nitrous oxide and increasing how much oxygen there is in your engine, the process can backfire and damage your engine.

Assisted turbocharging

Assisted turbocharging helps decrease lag by injecting more power into the turbo using external equipment such as a supercharger, an extra turbocharger, electric motors, or extra compressors. Some manufacturers have gone as far as to develop electric turbochargers because of improved technology.

Sequential turbocharging

This approach is among the most effective ways of minimising turbo lag in turbocharged vehicles. How does this approach work? Sequential turbocharging is done by pairing a small turbo making energy from about 2500 to 4000 rpm and a second larger turbo making power that utilises about 4000 to 6000 rpm to make an engine that has a large operating powerband.

Although the use of sequential turbocharging is effective in reducing turbo lag, they have one primary setback. The disadvantage of using sequential turbocharging is that they are expensive and more complicated to use. Further, they are minimally used for gasoline-related purposes; their use is more prevalent in the diesel world, where they have been utilised for more than forty years.

Contact An Expert About Turbo Lag

In the past, turbo lag was such a big deal that one had to think carefully when choosing a turbo car to buy. However, because of improved technology and the popularity of the turbo, turbo lag is no longer a problem. Smaller turbos spool faster than large ones.

Under some circumstances, car manufacturers have chosen to improvise and use small and big turbos simultaneously to facilitate linear power delivery. Compact turbos spool up faster at low to moderate speeds, while larger ones offer a range of moderately high speeds.

The result is that there will be smooth and consistent power from the engine hence little or no turbo lag. If you are in the market for a new vehicle and there just happens to be one with a turbocharger available, you should consider the information provided in this article. There are several solutions to solve turbo lag issues.

Talk to an expert car buying and selling company if in doubt or experiencing turbo lag, as they will be able to suggest a solution appropriate for your specific situation. It's often best to work with a professional dealership to ensure you get a long-lasting solution rather than a quick fix that may not be efficient in the long run.