Getting something for nothing is always a good thing. When modding a car, usually every modification has drawbacks. Get more power? Usually more power means more stress on things, more emissions, less mileage more noise. You don’t often get something for nothing. We tested the Civic Si intercooler from Garrett Advancing Motion and found that it worked spectacularly in reducing charge air temperatures and gave us great gains in power with no penalties! This is something worth noting as with ever evolving, well engineered late model cars, it is getting harder and harder to extract significant gains in power with simple bolt-ons.
Looking at the Garrett intercooler, we can see that it a generously sized bar and plate design. Bar and plate intercoolers have a lot of thermal mass, which means they can act as a very generous heat sink and initially pull a lot of temperature out of the charge air. As long as you have adequate frontal area and air flow, this means that they can be a most effective heat exchanger. Bar and plate intercoolers are a lot stronger than the other common type of intercoolers, like the tube and fin, and can take rocks and other debris hits better with little damage. The only slight disadvantage that a bar and plate core has is that they tend to be a bit heavier than a tube and fin. The Garrett bar and plate intercooler core has internal turbulators that slow the air to give it more time through the core to exchange heat and to also give more heat conducting paths to the outside of the tube for better heat transfer. Cheap copy cat bar and plate intercoolers, like those sold on ebay and such, are usually lacking these internal turbulators.
The Garrett intercooler has smooth aerodynamically shaped cast end tanks for the best flow and the most even distribution of charge air flow across the intercooler core possible. This helps make cooling better and results in less pressure drop across the core. Garrett used CFD studies to determine the best end tank shape.
The Garrett end tanks have the correct bosses so the OEM charge pipes will fit perfectly to them with no leaks. The end tanks also have provisions for the stock chassis mounts making the intercooler a true bolt-in part. The intercooler is assembled with strong tig welding for leak and crack free service.
Here you can see the thermal and CFD analysis output for heat exchange and flow across the core. As you can see the charge air flow and the heat dissipation are very well handled by the intercooler end tank design. The swoopy smooth endtanks contribute a lot to how the intercooler performs. We were impressed with how evenly the heat is distributed across the face of the intercooler. With other intercoolers with hand fabricated end tanks when scanning the face of the intercooler with an IR thermometer we have often observed a big temperature gradient.