The Ford Mustang GT is one of the most popular performance cars to date. Since it was created in 1964, the Mustang GT has been an almost constant fixture on the SCCA racing scene, as well as the Trans-Am series of the 1960s and the 1970s. Increasing the horsepower of the Ford Mustang GT, and particularly the current generation 5.0 liter GT, is a matter of simply swapping out engine parts for horsepower-building aftermarket components. These components are usually available at your local auto parts store, but if you can’t find them there, special order catalogs are typically the best place to look. The ideal place to start any engine customization, but most particularly with the Ford Mustang GT, is to feed the engine. More fuel, more air, and more exhaust.
Begin your Mustang GT horsepower build by purchasing the components you’ll need to complete the project. You’ll need a cold air intake system, high-flow dual exhaust, and high-flow fuel injectors. All of these parts build horsepower in the Mustang GT by reducing the restriction on the engine. However, it must be noted that by installing high-flow fuel injectors, you will invariably end up using more fuel, and as such, your gas mileage will be decreased. You can perform the horsepower improvement with just the exhaust and intake, but the effect will be lessened somewhat.
Under the hood of the Mustang GT, you will see the placement of the stock fuel injectors under the plastic covers on either side of the engine. Begin by locating the fuel pump fuse in the main fuse block. There is a diagram on the back of the fuse box cover. Start the engine, and then pull the fuel pump fuse and let the engine die. This will ensure that there is no fuel in the fuel rails. The individual injectors can then be removed and replaced with the high-flow injectors. Follow the instructions you find with the replacement injectors to ensure that you install them correctly, and then replace the covers onto the engine and replace the fuel pump fuse into the fuse block. Turn the key to the accessory position, and you will hear a buzzing sound. This sound is the fuel pump sending fuel to the injectors. When the buzzing stops, start the Mustang GT as you normally would. Do not allow the engine to heat up before you’ve installed the intake and exhaust.
A cold-air intake on your Mustang GT engine improves horsepower by allowing denser, cooler air to enter the combustion chamber. With the greater amount of fuel and air for the engine to use for each stroke, it will be able to produce more horsepower. The stock air box is located on the driver’s side of the engine compartment, just behind the front headlight. Use a screwdriver to remove the box, and then remove the air hose from the throttle body located on the front of the Mustang GT engine. You will also have to remove the sensors from the intake tube, but be careful with them when you do. They can be extremely expensive to replace.
Install the metal heat shield between the Mustang’s core support and the inner fender, and then assemble the cold-air intake. It will thread through the hole in the heat shield and attach to the throttle body of the engine. Plug the necessary sensors into the cold-air intake tube, and then install the conical air filter if you haven’t already done so. Make certain that all the fittings are tight and all the sensors in place before continuing.
To increase horsepower in the Mustang GT, it is important to install the correct exhaust system onto the car. In most cases, catalytic converter-back exhaust systems are sufficient not only to improve exhaust flow, but also to maintain the exhaust efficiency of the engine, allowing your Mustang GT to pass emissions tests without significant problems. This is because emissions tests don’t test the muffler, but rather the ability of the catalytic converter, to remove carbon monoxide from the exhaust. On the Mustang GT, all you have to do is unbolt the old exhaust from the converter and thread it over the rear axle to remove it. With the old exhaust out of the way, a dual-exhaust system for the Mustang GT slides over the rear axle and bolts into exactly the same place as the old exhaust, using the same hardware. Take care to avoid damaging the rubber exhaust hangers positioned at the back of the car, however. these help avoid rattles and other sounds you don’t want to hear from entering the Mustang GT’s cabin.
With these modifications in place, you should reasonable be able to expect a horsepower improvement of anywhere between 25 and 40 horsepower, depending on the condition of the engine and the mileage at the time of the modification. While improving horsepower in the Ford Mustang GT might be hard work, it’s worth it every time you drop the hammer when the light goes green.
Sources:
Mustang Monthly.com: Steeda Ultimate Induction Pak Installation; Jim Smart:
http://www.mustangmonthly.com/howto/mump_1103_steeda_ultimate_induction_pak_installation/index.html
Popular Mechanics.com: How to Install a Cat-Back Exhaust System; Mike Allen:
http://www.popularmechanics.com/cars/how-to/maintenance/4270747