Your car has to be cool on the inside as well as outside. This will serve you as the ultimate guide to achieving that by choosing the right intercooler
The process of choosing an intercooler is sure to be a daunting one for first timers. People unfamiliar with the technology are afraid to ask questions in fear of being laughed at. We however, do not see it that way. It’s completely normal to be unsure of what to install and the power gains you will observe, especially if you are dabbling with modifications for the first time.
That is why in this guide, Proto Performance will delve into detail explaining various intercooler systems, their designs, features and general capabilities, as well as cover the basics. This knowledge will help you squeeze the most power for the money, without going overboard in terms of size and value as many do. A well optimized system is far more capable than simply a big one.
- So, what does an intercooler do?
As you know, turbocharging has been an integral part of the automotive industry for more than forty years now. The last decade has seen a massive increase in the use of the technology as manufacturers are looking to downsize their engines, but at the same time increase power and improve fuel economy. The technology allows to turn something that would have otherwise gone to waste into sweet, sweet power.
A turbocharger uses waste escape gases which spin a turbine used to compress the air from the intake, thus forcing more of it in the combustion chamber. More air in the cylinder equals a bigger bang and ultimately, more power. This is all well and good, however, when air is compressed, its temperature rises and density decreases, which goes against the idea of actually getting more air in the cylinder. As such, the intercooler introduces cold air into the throttle body, increasing its density and putting more of it in the engine.
All that air is routed throughout the engine with a series of pipes, which depending on the complexity of the build can be either plastic, steel or aluminium. The pipes snake around the engine connecting the turbo to the intercooler and it to the intake manifold. So, knowing the basics, let’s talk intercoolers.
In laymen terms, the intercooler is nothing more than a heat exchanger. Hot gases in the range of 100°C – 135°C enter from the turbocharger. The external fins on the intercooler provide a massive surface area for the hot air to escape. As well as producing more power, introducing colder air in the combustion chamber also prevents premature detonations, also known as engine knocking. The phenomenon can cause rapid overheating and in many cases, catastrophic engine failure.
When it comes to choosing an intercooler, there are basically two types: Liquid-to-Air and Air-to-Air. Choosing between the two depends on the type of build and power produced. Let’s first talk about the more complex and expensive variant.
- Liquid-to-Air
This system is more efficient, but at the same time far more complex as it uses a secondary circuit with engine coolant. It works on the same principle a liquid cooled PC does. The air and coolant never come into contact. Instead the liquid is pumped through channels attached to the fins and the air is cooled as it passes between them.
This system is mainly used when packaging is of great importance, as the intercooler doesn’t have to be positioned in a place with great airflow, but we will talk about location in a bit. Its main advantage is the thermal efficiency which is perfect for big or just very high strung engines like for example, the CLA45 AMG.
- Air-to-Air
This is the more conventional approach to intercoolers. The system relies on direct air flow which cools the hot air passing through the veins. Although simpler, this system can suffer from overheating in hot climates or just lots of idling and heavy traffic. However, proper placement eliminates those issues to a large degree. It’s also far simpler mechanically, cheaper, easier to install and maintain. This is the go to system if you are not building a dedicated race or rally machine, but a more than capable road car.
So why is the location important?
The location again really depends on what you are going for. There are three ways to install an intercooler – on the top, front or side. The first two are the more popular, as the side mounted intercoolers really compromise the size of the heat exchanger.
Top mounted intercoolers are mainly seen on Subaru models like the WRX and STI. This location finds its roots in rallying where you wouldn’t want a rogue rock to just fly in and smash into the bumper mounted exchanger. It also reduces the piping complexity, which as well as being cheaper, softens turbo lag as the air doesn’t have to go on an epic journey around the powertrain.
Top mounted intercoolers are more prone to overheating as the hot air rising from the engine passes around them. This can be a problem at idle, but the flip side is that such a configuration can handle more power.
Front mounted intercoolers are the more popular ones, as they are an easier fit and far more effective at heat transfer due to the massive amount of air passing through them. One thing to note with them is that not every single car allows for the exchanger to be mounted underneath the radiator. In some cases, it does go in front of it which can cause separate issues with cooling the engine itself. For such installations it is better to go with a slimmer unit which leaves as much radiator open to the elements as possible.
At the end of the day, that is why we are here – to help you overcome these hurdles and make the optimal choice. In the following articles we will continue to familiarize you with the intricacies of the intercooler and advice you on what to look for. Stay tuned.