Best ultimate Turbo Guide for Beginners (parts, functions and more)

Vrmmmm stutututu… So you are looking to buy a turbo to have a fast car that make cool sounds? Or maybe you are looking to start racing and just want to achieve certain power goals.

Whatever the case may be if you want to know the necessary about turbochargers you are at the right place.

In this article, we will go over what is a turbo, how it works, the different parts of a turbo system, turbo lag, and more.

Turbo

what is a turbo

A turbo or turbocharger is one of the many styles of forced induction. Forced inductions means it forces air into your engine’s combustion chamber in this case using a turbine.

This means that a turbocharger coupled with performance fuel injectors, other performance mods, and a proper fuel-to-air ratio tuning for example can allow for bigger combustions and thus more power.

How does a turbo generate more power

To understand why people turbo their cars and why it allows for more power you first need to understand how an engine works.

An engine is theoretically a big pump that sucks in air and fuel into a cylinder. Afterward, it compresses and combusts this fuel/air (1) mixture before pumping it back out through the exhaust.

Therefore for an engine to make more power, it needs to burn more fuel more quickly. Adding fuel is not the hard part as you can upgrade your fuel system to push out bigger volumes of fuel at a quicker rate.

However, more fuel without the addition of more air is pointless. The problem is that the cylinder size is the limitation to how much air it can pull in or in other words the cylinder “displacement”.

Therefore before the invention of forced induction such as turbochargers, the only way to pull in more air was to use bigger cylinders. However, if you want your engine to fit inside the engine bay of your car there is also a limit to how big it can be.

So, this is why turbos were invented.

They compress and force more air into the engine cylinder via a turbine. This means with a turbo you can intake more air in your cylinder and therefore more fuel causing bigger bangs (combustions) and more power.

How does a turbo work

Turbo parts name
Blow off valve and Intercooler
Wastegate

The turbo basics

A turbo consists of two sides: An exhaust side also known as the hot side and an intake side.

Each side contains a turbine and both turbines are connected in the middle.

As the engine runs, exhaust gases and pressure are produced, which travel through the exhaust side of the turbo and spin the exhaust turbine. The exhaust gases continue their journey out of the turbine port and into the exhaust, where they are eventually released from the vehicle’s system.

Because the exhaust turbine is linked to the intake turbine, when the exhaust turbine spins, the intake turbine spins with it.

Therefore, the intake turbine draws a large amount of air, compresses it, and forces it into the intake manifold. The air becomes denser and thus richer in oxygen, allowing more gas to be burned more quickly.

What is a blow off valve

The blow off valve is essentially nothing more than a pressure relief valve.

The turbo generates high pressure to ensure that the fresh air is forced into your intake. This pressure is beneficial while the turbo is spinning. However, once you let go of the throttle, you don’t want this pressure to return to the turbo.

This is where a blow off valve comes into play.

When you let go of the throttle, the blow off valve releases the pressure buildup, ensuring that no pressure returns to the turbo.

The blow off valve is also responsible for the iconic “Stutututu” or “Pshhhhh” sounds.

More precisely, the “Stutututu” sound occurs when the blow off valve does not completely release the pressure and some of it returns to the turbo and exits through the intake. When this happens, the air is “sliced” by the turbine, resulting in this famous sound.

What is an Intercooler

An intercooler does exactly what it says it does: it cools. More precisely cooling the compressed air between the turbo and your engine’s intake.

The cooling part is very important to achieve maximal power. Because, while the intake side will not reach the same temperature as the exhaust side, it can warm up a great deal.

When compressing air you force the molecules closer together generating friction. (2) This friction warms the molecules, causing them to move faster and lose density. This contradicts the whole point of forced induction which is to force as much dense air as possible into the engine.

As a result, the intercooler is located between the turbo and the engine.

It cools the air by dissipating heat through a series of fins and plates. The air is forced through the intercooler, and the fins help to transfer the heat from the air or to the surrounding atmosphere making the air cooler and denser again.

What is a wastegate

A wastegate is an exhaust gas pressure release valve that controls turbo speed and boost pressure.

It works in the same way as a blow off valve, but it is either located inside the turbocharger (internal wastegate) or between the exhaust manifold and the turbo (external wastegate).

The higher the RPM of an engine, the more exhaust gas flows to the turbo, causing it to spin faster. Without a wastegate, your turbocharger will always be operating at the maximum pressure achievable according to your engine’s RPM .

Not only is running your turbo at full power bad it’s longevity, but many engines do not require or cannot handle full boost.

Slowing down a turbocharger is the only way to limit the amount of boosted air produced. To slow it down, you must reduce the flow of exhaust gas passing through it, which can be accomplished by redirecting a portion of the flow past your turbo once it reaches a certain pressure.

A wastegate is operated by a spring. The spring inside your wastegate can be softer or stiffer, which determines how much pressure (PSI) is required to push the spring open and release pressure.

For example, a spring rated at 18 psi will be stiff enough to retain 18 psi of pressure but will begin to stretch or compress beyond this pressure, opening the wastegate.

what is turbo lag

Have you ever used a laggy computer that takes 3 seconds to register every time you press a button? Well, annoyingly enough turbos can also be laggy.

The definition of turbo lag is the time necessary for the boost to kick in after activating the throttle.

When purchasing a turbo, you may be tempted to get the largest one possible in order to generate the most power. However, if the it is too large, the exhaust will take a long time to get it spinning fast enough to compress the fresh air and generate boost.

This time or delay is referred to as turbo lag.

how to reduce turbo lag

Now what if you still want to buy a big turbocharger but eliminate the lag? Well fortunately engineers and racers throughout the years have figured out a couple of methods to indeed reduce if not eliminate turbo lag.

Here are 4 different ways you can reduce lag.

  • 1: Anti-Lag
  • 2: Twin Turbo Setups
  • 3: Nitrous Oxide (NOS)
  • 4: Alternative Force Induction

1. anti-lag

Anti-lag is the main and the most known method to reduce turbo lag. It was first introduced in racing in the late 1980s. Anti-lag is a very simple concept that consists of tuning the timing of your engine.

The goal is for an excess of fuel/air mixture to escape through the exhaust valves and combust in the hot exhaust manifold, spooling the turbocharger and increasing usable pressure.

Obviously having a combustion happening in your exhaust manifold is not ideal for the overall longevity of your parts but is great for racing performance.

The reason is that when you step off the throttle the turbo will naturally start to slow down and will have to spool back up when you step back onto the throttle creating lag.

By allowing a combustion to happen outside the cylinder after you release the throttle the force of this combustion will keep the turbine spinning at high RPM offering maximal power at all times.

2: twin turbo

Another excellent way to reduce lag is to use a twin turbo system. In most cases, a twin sequential system with two different sized turbochargers is the best option.

I’ll keep it brief because we’ll be discussing twin turbo setups later in this article.

A sequential setup consists of two turbochargers, each of which is activated at a different time (RPM level). To have maximum boost throughout your engine’s RPM range, many people will have one small turbo and a large one.

The smaller turbo will spool up faster and provide an instant boost at low RPM , while the larger one will be spooled up and ready to take over and provide higher boost levels at higher RPM .

This type of system with two different turbo sizes ensures boost at all RPM levels, which is an excellent way to reduce excessive lag.

3: Nitrous Oxide (NOS)

Using nitrous oxide (NOS) (3) to eliminate lag is a great but expensive way to do it. This method works by utilizing nitrous shots at low RPM and the boost of a big turbocharger at high RPM .

Utilizing the nitrous shot at a low RPM will also help your engine to reach high RPM faster and therefore access the turbo boost sooner.

As we said above, this method is great for performance, but in the long run, nitrous can become a big expense. This is one of the reasons it is more useful for racing than street purposes.

4: Alternative forced Induction

If you really do not want to deal with any lag whatsoever, considering a different forced induction option might be the way to go for you.

For example, going for a supercharger (4) instead of a turbo. Superchargers are connected directly to your crankshaft via a belt and therefore the supercharger spins with your crankshaft. This means that boost is instant.

the different twin turbo setups

The most common twin turbo system you will find are:

  • 1: Parallel
  • 2: Sequential
  • 3: Series

1: parallel

Parallel turbo system

A parallel turbo system consists of using 2 or more equally sized turbochargers all running entirely independent from one another.

Each turbo will be controlled and will boost their own equally shared and separated part of the engine. This means that each turbocharger will have its own exhaust manifold (equally separated between the turbos), wastegate, intake piping, and blow off valve.

The only parts that are sometimes shared between turbos in this type of setup are the intercooler and intake manifold.

This system is commonly found on V-type engines. (5) Since it makes the tubing job inside the engine bay much cleaner and easier. This is because each turbo can be powered by its own side.

2: Sequential

A sequential turbo refers to a setup in which the engine uses one turbocharger for lower engine RPM and a second or both turbochargers at higher engine rpm.

In this type of setup, both turbos can be the same size but also two different sizes which is the most common choice. As a result, sequential turbocharger systems reduce lag while maintaining power output at high RPM by employing one small and one large turbo.

The system is configured in such a way that a small turbocharger operates while the engine is running at low RPM, to offer an efficient amount boost and reduce turbo lag.

As the RPM rises, a small amount of exhaust gas starts to flow to the bigger turbocharger in order to get it up to speed.

The exhaust gases are then fully redirected to the secondary turbocharger at high RPM so that it may deliver the boost required by the engine at high speed.

3: Series

Series twin turbo systems are fairly straightforward.

Serial turbocharging is achieved by connecting the turbochargers in series, with the output of the first turbocharger fed into the second turbocharger to be further compressed. Often, if not always, the first turbo will be smaller than the second.

Because this type of system typically results in high levels of boost lag, it is commonly used for applications that do not require rapid acceleration.

What is the best turbo brand?

Are you currently searching for a new turbocharger for your project car? Take a look at our latest article: 7 best turbo brand for your car 2023 (reviews)

In this article, we go over the best turbo brand for any application such as:

  • Garrett: Versatility
  • Precision turbo & engine: Racing Performance
  • BorgWarner: Performance Technology
  • Turbonetics: Aftermarket Performance
  • Xona: Durability
  • Bullseye Power: Custom Turbochargers
  • Holset: Diesel

conclusion

In conclusion, a turbo or turbocharger is a type of forced induction that enhances the power output of an engine by forcing more air into the combustion chamber. When compressing and forcing more air into the cylinder, you can add more fuel, creating larger combustions and therefore more power.

The turbo consists of two sides: the exhaust side, which uses exhaust gases to spin the turbine, and the intake side, which draws in air, compresses it, and forces it into the intake manifold. A turbo system will consist of the turbocharger, a blow off valve, an intercooler, a wastegate, and all the tubing connecting everything.

Turbo lag, the delay of boost activation, can be reduced through methods like anti-lag, twin turbo setups, nitrous oxide, or alternative forced induction options. Twin turbo systems mainly consist of the following: parallel, sequential, or series setups.

Ultimately, turbos and their associated components play a crucial role in enhancing engine performance and power output.