What Exactly Is Heat Soak? Heat Soak for the Engine and Turbo. In the automotive industry, heat soak is a fairly broad phrase. That basically signifies that some portion of the engine is growing excessively hot and overpowering the system’s capability. Yet, engine heat absorption is a complex process. It’s also perplexing because people use the term in various ways. But don’t worry. In this essay, we’ll explain what heat soak is. We’ll also go over the symptoms and consequences of engine heat soaking.
What Exactly Is Heat Soak?
Heat soak simply refers to a portion of the engine – or the engine as a whole – becoming overheated. Engines generate a lot of heat, and that heat has to go somewhere. It absorbs metals and fluids. As it becomes hot enough, heat absorption decreases and the engine can no longer efficiently rid itself of extra heat.
This phenomena is commonly observed on race tracks, canyon runs, at high elevation, when carrying big loads, and so forth. These are instances in which the engine is working hard for an extended period of time. It’s very frequent on forced induction engines, particularly turbocharged engines. Because turbo heat soak is a large topic, we’ll return to it later in this article.
The most common type of heat soak is related to intake air temperatures (IAT). Because hotter air is narrower, there is less oxygen, resulting in power loss. The engine also becomes more prone to pre-detonation, which increases the chance of the motor blowing up. As a result, the computer will draw timing, resulting in additional power loss. Heat soak is a viscous cycle with serious consequences for engine health and performance.
Why Is Heat Soak Harmful?
We only touched on it briefly, but there’s a lot that goes into heat soak. As we discussed, many people associate it with IATs. It can, however, be an infinite cycle that begins with one part of an engine and gradually heats up the entire engine.
A turbocharger, for example, begins heat absorbing. This, in turn, overloads the intercooler and raises IATs. Internally, higher input temperatures generate greater heat. Heat soak begins with the oil and coolant. As metals expand with heat, their viscosity decreases, friction increases, and clearances tighten. There is coolant and oil running through the turbo(s), and those fluids are absorbing even more surplus heat.
Engine heat soak is usually not a big concern in short bursts as long as the engine is given enough time to cool down. Yet, prolonged heat soak causes significant load and wear on the engine. Individuals who experience heat soak issues on a regular basis should attempt to fix them with the necessary changes.
Signs of Engine Heat Soak
Among the symptoms that point to heat soak are:
- Power outage
- Inadequate performance
- IATs that are high
- Overheating of Coolant/Oil
- Trying to return to normalcy
The major reason heat soaks cause power loss is because IATs rise. Hotter air is less dense, and it also causes the computer’s timing to be delayed. Power loss and poor performance are likely to be quite obvious with severe IAT heat soak.
Keep an eye on the numbers on your oil and/or coolant temperature gauges. Understanding the appropriate numbers for your engine is important because different engines operate at different temperatures. All engines become hot at times, and you might notice it after a few rapid WOT runs. Unfortunately, heat soak is not always the case. Heat soak is characterized by the engine laboring to cool down because fluids and metals can take a long time to dissipate heat when they are overloaded.
Bathing in Hot Water at High Speed
Heat soak on turbo engines is a prevalent problem in many new cars. It’s less typical on fully stock vehicles. Some cars and engines, however, may be more or less susceptible. The actual issue with heat soaking on turbo engines is that they are so simple to adjust and modify. Most modern turbo engines can be taken to the next level with a tune and some simple bolt-on mods.
Heat soak is also more common in superchargers and other forced induction engines. As air is compressed, it heats up. Unfortunately, turbos operate on highly hot exhaust gases, exacerbating the problem. The increase in boost and heat quickly overwhelms factory intercoolers.
Intercooler modifications are an excellent approach to reduce heat soak, but they may not be sufficient for race vehicles and other demanding applications. Further cooling upgrades, such as oil coolers, radiators, and so on, will almost certainly be required.
Related : The Three Most Frequent Toyota 2UZ-FE Engine Issues
Air-to-Water Intercoolers vs. FMIC
So, here is the final piece, and it should give you a better understanding of what heat soak is. Front mount intercoolers (FMIC) are a popular way to cool charge air. Air-to-air intercoolers are a more formal term for them. FMICs are used by many racing teams and race cars. Air-to-water intercoolers, on the other hand, are becoming increasingly prevalent in OEM turbo engines.
Air-to-water intercoolers are fantastic for a variety of reasons. A water/coolant mixture can carry more heat than air. As a result, an air-to-water intercooler is less prone to heat soaking. They can, however, experience heat soaking, which is even worse than with an air-to-air FMIC. This is because the water will take much longer to expel the surplus heat. Air cools more quickly than water.
As a result, FMICs are still a popular alternative in racing. It’s only one illustration of how much goes into engine and turbo heat soak. Heat isn’t the only determining aspect in heat soak because how soon items may cool down after soaking is also essential.
