How Does A Turbo Intercooler Work On A Diesel Engine?

An intercooler is a heat exchanger that sits between the supercharger and the intake manifold on a car engine. Its duty is to absorb and disperse the heat in the charge air so that the engine can breathe the coolest, densest air possible.

Why do diesels need an intercooler?

An intercooler on a diesel engine is essential for preventing the engine from experiencing temperatures that could melt pistons, damage valves, or destroy a turbocharger. While OEM intercoolers will enough for most people, many in the performance industry prefer to double or triple the horsepower of their vehicles, which necessitates upgrading to aftermarket units with larger cores and greater boost ratings (the AFE cooler pictured below is rated for a whopping 200 psi). While adding an aftermarket intercooler typically results in EGT decreases of 100 to 200 degrees, we’ve seen an air-to-air unit from BD Diesel cool EGT by 250 degrees in an over-fueled 5.9L Cummins application.

Does a turbo intercooler use coolant?

Intercoolers, which are found in turbocharged and supercharged engines, provide much-needed cooling that a single radiator cannot supply. We’ll go through why you might need one before we go over how they function.

For the purpose of simplicity, we’ll utilize turbocharger-equipped engines as an example. While compressing air, turbocharged engines generate a lot of heat, which aids in squeezing as much air as possible into the engine.

More power means more air (among various other benefits such as fuel efficiency and reduced waste). That may appear straightforward, but compressed air becomes extremely heated, resulting in a loss of density and, as a result, oxygen.

Oxygen is essential because it helps combustion in the fuel-air mixture. The compressed air must be chilled in order to increase density and oxygen content, which is where the intercooler comes in.

From hot to cold

In high-performance automobile applications, a forced induction engine is typical. It offers a variety of advantages while remaining lightweight, which is a huge plus, especially for racing.

In extreme situations, though, all that compressed air can reach temperatures of above 205 ° C. As previously stated, heated compressed air is not conducive to combustion. An intercooler can help with this.

This is aided by the intercooler, which cools the air before it enters the engine and combustion chamber. Depending on the type of intercooler, the cooling process may differ slightly.

Types of intercoolers

An intercooler is a heat exchanger that cools air by passing it via fins, similar to a radiator. Intercoolers are divided into two categories:

This is the most popular use for daily vehicles because it is a fairly basic system that involves:

It works similarly to a radiator in that it relies on ambient airflow from the front of the automobile to go through the intercooler and cool the compressed air.

A liquid to air intercooler is significantly more complicated, but because of its increased efficiency, it is becoming increasingly used in automobiles. The procedure is as follows:

  • The air is heated and transported to the intercooler, where it is cooled before being sent to the engine.
  • The hot coolant is cycled to the radiator, which then returns the cold coolant to the intercooler for further cooling.

Because there are two circuits carrying air or coolant, more accessories and fittings, such as hoses, are frequently required. As a result, it’s a touch pricey, but it’s still a very effective technology – especially in applications like drag racing automobiles.

One potential issue is heat soak, which occurs when there is a build-up of residual heat near the engine and insufficient cooling capacity to lower the temperature.

This may usually be fixed by letting the car run for a few minutes before turning it off to allow the cooling system to continue to work.

Using ice or other substances for brief periods of time can increase efficiency.

Common intercooler faults

As previously stated, there are a few things to be aware of when it comes to intercoolers. Fortunately, most of them are simple solutions, but if you need to replace something, it’s not difficult to do so. Among the most common intercooler issues are (but are not limited to):

  • Heat soak or overheating (due to bad intercooler placement and reliant on ambient airflow)

Signs and symptoms

  • Coolant leakage is noticeable (which could indicate other problems such as radiator failure)

If your intercooler needs to be repaired, Natrad workshops all around Australia can help. If fixing isn’t a possibility, Natrad offers a variety of intercooler parts as well as custom-made replacements.

What is the purpose of turbo intercooler?

The intercooler’s primary function is to lower the temperature of hot air compressed by the turbocharger before it reaches the combustion chamber of the engine.

Can you run a turbo without an intercooler?

Running a turbo without an intercooler allows hot air into the combustion chamber, causing it to detonate prematurely. Because there is no intercooler to cool the air before it enters the engine, using a turbo without one will result in extremely hot air entering the engine.

Does an intercooler improve performance?

An intercooler is a device that cools the air that is pumped into a car’s engine. Because the act of compressing air in turbochargers or superchargers causes the air going for the engine to heat up, it’s mostly used in turbocharged or supercharged autos.

The intercooler minimizes the chance of detonation in the engine by assisting in the cooling of compressed air as it goes to the engine. It also generates a richer air-to-fuel mix in the engine’s cylinders by making compressed air denser when it enters the intake manifold. As a result, power output is boosted.

So, yeah, the question is answered! The use of an intercooler aids in the growth of horsepower. If your car’s engine is naturally aspirated, though, an intercooler isn’t necessary. This is because the air delivered to such an engine from the radiator and cooling system ducts is already at a low temperature. The output of an aspirated engine will be unaffected by the addition of an intercooler.

Let’s have a look at the many types of intercoolers that you could use to modify your engine.

What are the benefits of an intercooler?

The entire system is exposed to debris because FMIC systems require an open bumper design for best operation. Because of this concern about reliability, some engineers choose for different mount sites. Depending on the engine’s heat dissipation needs, FMICs can be placed in front of or behind the radiator.

Intercoolers play an important role in managing internal temperatures in turbocharged engines, as well as allowing more air to be allowed to the engine. The specific power of an engine is boosted when it is installed with a turbo (as it is with any form of supercharging), resulting in higher combustion and exhaust temperatures. The exhaust gases going through the turbocharger’s turbine section are generally approximately 450 °C (840 °F), but they can reach 1000 °C (1830 °F) in exceptional conditions. This heat flows through the turbocharger unit and helps to warm the air being squeezed in the turbo’s compressor section. If this hot air is not cooled, it enters the engine, raising internal temperatures even more. This causes a build-up of heat that will eventually cool down, but at temperatures that are higher than the engine’s design limits—’hot spots’ on the piston crown or exhaust valve might cause warping or cracking of these components. Pre-ignition or detonation will be more likely if the air charge temperature is too high. Detonation creates destructive pressure spikes in the cylinders of the engine, which can swiftly damage it. These effects are particularly noticeable in modified or tuned engines with extremely high specific power outputs. An effective intercooler removes heat from the induction system’s air, reducing cyclic heat build-up via the turbocharger and allowing for larger power outputs without harm.

The intake air heats up owing to turbocharger compression, and heat is added due to compressor inefficiencies (adiabatic efficiency). The greater cause of the rise in air temperature in an air charge is this. Forced induction produces more power because there is more air available to burn more fuel in each cylinder. For a given fuel’s octane rating, this may necessitate a lower compression ratio to allow for a wider range of ignition timing advance before detonation. A lower compression ratio, on the other hand, reduces combustion efficiency and increases power consumption.

Some high-performance tuning firms take temperature readings before and after the intercooler to guarantee that the output temperature is as near to ambient as possible (without the use of additional cooling; water/liquid gas spray kits).

What does an intercooler upgrade do?

Overall, it appears that cooler air is a win-win situation. With our post on intakes, we discussed one approach to optimize this airflow, but when it comes to turbo automobiles, there’s more to the tale than just an intake.

When we use a turbocharger or supercharger, we increase the density of the air, which has one unfavorable side effect: the temperature of the charged air rises dramatically. In fact, as we increase boost pressure, we add more energy to the system, some of which is turned into heat. We need a technique to cool down the hot air before it enters the engine because it contains everything we don’t want. Unfortunately, that is the intercooler’s job. In its most basic form, an intercooler is a heat exchanger that cools charged air.

The intercooler(s) in your stock Audi or VW are sized to meet the system’s minimum requirements. On a standard tune, it will keep the air cool enough to prevent pre-detonation, but not much more. Furthermore, stock intercoolers have a low-cost tube-and-fin design (more on that later). As a result, while the system is effective, it leaves a lot to be desired.

The apparent is the first noticeable alteration of an intercooler. Reduce the temperature of the air. The most obvious consequence is an increase in horsepower due to higher air density. We increase the density of the air by lowering its temperature. We can generate more power if we circulate the same amount of air at a higher density! Not only that, but cooler air has a lower chance of detonating. This means we can advance the intake ignition time to increase the engine’s efficiency. Many current ECUs, like as those found on the MK7, will automatically calibrate and advance timing in order to take advantage of the cooler, safer air. Don’t just take our word for it, though. Check out the extensive power charts from Integrated Engineering! (MK7R data as an example)

Pre-ignition, often known as “knocking” or “pinging,” is more likely to occur when the air is hotter. This is a complicated problem, but the short version is that pre-detonation causes significant wear on engine components and can lead to premature engine failure. Engine knock is possible if you regularly flog your car in a hot climate with the OEM intercooler. The use of an improved intercooler to cool the intake air minimizes the chances of engine knock, perhaps saving your engine! For a more complete explanation of engine knock and timing progression, read this article.

How much HP does a intercooler add on a diesel?

You gain one percent horsepower for every ten degrees cooler. Three percent more horsepower is gained for every one psi increase in boost.

Do all turbo engines have an intercooler?

And, we increase the boost pressures even more……any gas heats up on compression, and beyond a certain amount of boost, the air charge will heat up to the point where it will burn your pistons… the intercooler is employed to lower the air charge temperature and obtain higher boost pressure….

A front mount intercooler (that shiny radiator you see) allows for higher flow and temperature drop, allowing for higher boost pressures…… All turbo cars have an intercooler (gas), but typical performance mods for them include a front mount intercooler (that shiny radiator you see) which allows for higher flow and temperature drop, allowing for higher boost pressures……