S197 Mustang Intercooler - New-School Cool

Steeda's Steve Chichisola positions the company's new high-capacity heat exchanger on the front of David and Tedd Siegel's '07 Shelby GT 500. This replacement for the stock exchanger reduces air-charge temps and provides greater overall cooling for the factory superchargers, or Roush and Magnacharger blowers for S197 Mustang GTs.

Horse Sense: The best way to comprehend the inefficiency of a heat-soaked supercharger is to imagine trying to move a ship's anchor that's stuck 100 feet below the ocean floor. Basically, hot air has the opposite effect on an engine than that of cold air-it hurts performance. In this case, heat inside the blower and the air charge it generates all but extinguishes an engine's ability to make good power.

Cool, crisp inlet-air temperature is a friend to all internal combustion engines. To put it in better perspective, cold air, as inlet air is commonly called in most high-performance circles, makes horsepower. We have no argument for that sentiment. We're always looking for and trying out new methods of increasing or improving the air that a naturally aspirated or power-adder-assisted Mustang engine takes in.

Air enhancement for S197s has been the hot ticket lately. The cars are super popular, and the aftermarket has seen to it that all types of cold-air intake systems, superchargers, turbos, and nitrous sets are readily available for the new '05-'08 'Stangs. For this exercise, we're looking at Steeda's new high-capacity heat exchanger (PN 555-3706; $449.95) for factory-supercharged Shelby GT 500s and S197 GTs that get additional oomph from positive-displacement blower offerings of Roush and Magnacharger.

Air-to-water intercooling is the primary method of lowering air temperature in supercharged '05-'08 Mustangs equipped with these types of superchargers. Blower-mounted intercoolers for both systems use engine coolant that passes through their cores to lower charged air's temperature just before it enters the engine.

Once the front bumper cover is void of its mounting hardware (bolts, screws, nuts, and other fasteners should be stored in a safe location), the Shelby's front bumper cover is carefully removed and set aside.

Often, especially when additional mods are made to increase horsepower, a Shelby's stock intercooler (or one included with a Roush or Magnacharger unit) loses its ability to disperse heat and maintain efficiency, despite the presence of radiator-style heat exchangers mounted behind the front bumper that serve as additional independent cooling systems for the blowers.

The root of the situation is, stock-type heat exchangers are too small, and they can't keep up with the amount of heat a supercharger generates and stores once a supercharged 4.6 or 5.4 makes serious steam.

The new Steeda heat exchanger we're installing is much bigger than the OEM Shelby GT 500 or those included with aftermarket units. It will increase superchargers' cooling by more than 160 percent, as flowing coolant will experience huge reductions in temperature, thanks to its increased size.

David and Tedd Siegel of Total Mustang Supply spotted us their lightly modded (CAI, pulley, and tune) Shelby GT 500 to use as the subject 'Stang in this effort, and Steeda's Steve Chichisola is our installer. Bolt-in time for this deal is approximately two and a half hours-it may take longer on Mustang GTs, as a few minor modifications are required. We feel the installation should be performed by 'Stang techs in a fully equipped shop. However, any mechanically adept Shelby owner probably will be able to take care of this install in the driveway, as long as a buddy or two is around to lend a hand.

The factory heat exchanger resides in front of the radiator, just behind the front bumper support on the driver side. Steve removes the bolts securing the unit and disconnects the lines that feed coolant in and out of its core...

...and then lowers and removes the heat exchanger. This part of the process is simple and straightforward.

Once the stock heat exchanger is out of the car, residual coolant from the cooler lines is captured.