The non-turbo Mitsubishi Eclipse does not have the power of its higher powered, turbocharged brethren. However, to convert the non-turbo Eclipse's stock 420A engine to the 4G63-T found in the Eclipse GST and GSX requires extensive modification to the chassis. A much easier and cheaper route is to turbocharge your non-turbo Eclipse.
Remove your Eclipse's front bumper to allow room for installation. Also, remove the stock intake, header, and exhaust, which you will replace with modified units from the turbo kit. Raise your Eclipse with a floor jack, and place on jack stands.
Bolt your turbo kit's exhaust manifold in place of the stock header, on the front of the engine. Attach the manifold's O2 sensor housing to the bottom of the manifold, and install the stock O2 sensor by threading it into the housing. Bolt the catalytic converter and after-cat exhaust in place, securing them to the exhaust manifold piping.
Secure the turbocharger unit to the front of the exhaust manifold. Connect all the oil and coolant lines into their designated hook-ups on the turbocharger. Attach your kit's turbo intake and/or air filter to the turbocharger's inlet with the supplied clamp ring.
Fit your turbo kit's intercooler into place in front of the radiator. Attach the intercooler J-pipe from the turbocharger's compressor side to the intercooler's inlet. Attach the intercooler up-pipe with the supplied blow-off valve installed to the intercooler's outlet. A small section of the fender liner needs to be trimmed with an angle grinder or equivalent cutting tool to fit the aftermarket intercooler piping. Secure all piping with clamp rings. Fit the intercooler up-pipe to the throttle body, and plug into it all stock lines and sensors.
Cut your Eclipse's bumper to fit around the intercooler, and then re-install it. Depending on the level of turbo upgrade, you may need to install other upgrades prior to tuning, such as an upgraded fuel pump and injectors. Also, replace the engine's oil and radiator fluid prior to startup, as the turbo system will require a larger amount of these fluids than the stock engine.
Tune your newly turbocharged Eclipse by installing either a piggyback tuner or fully tunable engine software. As power potential and reliability depend entirely on your vehicle's tune, it's best to have your Eclipse's turbo system tuned by a professional with a dyno service.
