Nerd’s Eye View: LA Auto Show 2014: Part 2 – Race Cars and Engines


Mark Higgins took this slightly modified STI to the fastest lap in a car around the Isle of Man. You’ve probably watched the vid which Subaru had looping on the little display stand, the guy has steel cojones the size of grapefruits.
The car was modified with some aftermarket coil-overs and a big free flowing exhaust. Of course a roll cage was installed, but otherwise, the car is remarkably stock.
This is Patrick Dempsey’s new ride (Dr. McDreamy to ladies). I did not poke around the car too much, but those NACA ducts in the front hood are for directing cooling air to something. Dempsey uses cycling for training riding Specialized bicycles. He also uses cycling to raise money for The Patrick Dempsey Center for Cancer Hope and Healing.
The car is fitted with one very wide air filter. The greater the surface area of the filter, the lower the pressure drop and therefore more power.
There’s not much to the exhaust… just a couple pipes that meet in the middle. No mufflers means reduced flow resistance and more power.
One of the highest power engines off the showroom floor is this 707hp supercharged Hemi. The sensor attached to the blower on the driver’s side is probably for boost pressure and/or air temperature. The size of the air box and the tube connecting to the blower are relatively massive to be as free flowing as possible for the mass of air required to make over 700hp.
The IHI supercharger uses twin screws each with a different number of lobes. Therefore, gears are required to spin one screw faster than the other. The black sensor to the left should be to measure air after it passes through the internal air-to-water intercooler. This would imply the other sensor in the previous picture is also to measure air temperature allowing the computer to determine how well the intercooler is operating. Based on the efficiency of the intercooler, there is probably some table in the ECU which adjusts the ignition and fueling to prevent knock. The two hose barbs on the right are for carrying the coolant to the intercoolers. The sensor on one of the coolant passages is probably to keep tabs on the coolant temperature.

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