Cooling The Intercooler - Garage.Tech

We probably should have found another car to test DEI's Cry02 Cryogenic Intercooler Sprayer on. Project Eclipse is finicky. Actually we're being a bit too kind; it's more of a two-steps-forward, one-step-backward kind of car. It seems as though every time we try and make something better, a couple of new yet unrelated problems make themselves known. We're hoping this just can't go on forever despite how much other 1G DSM owners seem to keep discouraging our optimism.

The logic for using our Eclipse to test the Cry02 system made sense at the time though, mostly because we're still using the factory-issued, side-mount intercooler and boosting a little more than one bar with our Big 16G turbocharger. We aren't experiencing any signs of detonation yet, but the measly, kid-sized intercooler core tucked behind the fenderwell could stand for some additional cooling off. Mitsubishi thought ahead and incorporated a fairly effective air duct into the front bumper, but a core this size, trapped behind plastic panels and sheetmetal, can only be so effective when generating such airflow. The fact is turbochargers create heat. When air is compressed, it heats up. The more it's compressed, the hotter things get. At 16 psi it puts us right in that hazy zone where we could get by with the side-mount but stepping up to a front-mount, or some alternative solution like methanol injection, would certainly yield gains.

Intercoolers, like radiators, are heat exchangers. Saying something's a heat exchanger is just a fancy way of saying that two or more fluids are interacting with one another, exchanging temperature properties, but without actually touching. Their job is to remove heat from the intake charge by means of air- or water-cooling. The results make for a denser charge, resulting in more power and reduced chances of detonation. About the only downsides to intercooling are fitting the system in place and pressure drops as high as a few psi depending on the core's efficiency. We found a solution that gives all the benefits of a larger intercooler without the bad stuff.

We've heard the drill before; cool air makes horsepower and there are several ways to get such horsepower. DEI relies on the properties of carbon dioxide for temperature dropping. In geek-speak, carbon dioxide is the chemical bond between two oxygen atoms and one carbon atom. This means important things like photosynthesis for plants can occur, allowing us to do things like breathe and live; cooling down your intake charge is just an added benefit although one we arguably appreciate more. Carbon dioxide also takes on other forms, like dry ice when converted to a solid state. As a by-product of the combustion process, it's a relatively harmful greenhouse gas, unlike its chemical relative, carbon monoxide. Sizable power gains have been found from intake charge cooling; it's not uncommon to find 1 percent horsepower gains for every 10 degrees temperatures drop.

Carbon dioxide is a relatively smart gas to use for cooling applications like ours. It's cheap, it's non-flammable, and its relatively low-pressure gas-to-liquid transition phase allows more to fit inside a bottle than you might think. About the only thing you need to be aware of when spraying C02 around an engine bay is its non-combustible nature. C02 ingested into your air filter and introduced into the combustion process won't make for a happy engine. It's not really something detrimental, it'll just put a major damper on things we care about like the way combustion was meant to occur and decent cylinder pressure. Keeping the spray away from the filter will ensure the C02 actually helps more than it hurts. Project Eclipse kept finding ways to ingest C02 no matter what we did. We found giving the intercooler a good spray down prior to a full-throttle pass provided similar results without taking in C02 when it counted most.