Make A Crown Victoria Police Interceptor Faster

A few modifications can boost your Crown Victoria’s speed and performance.

The Crown Victoria Police Interceptor, also known as the CVPI or the P71, remains the last rear-wheel V-8 in production in North America. New cars are only available to fleet buyers in law enforcement and transportation, but a vibrant trade in used specimens persists in the face of high energy costs. This car has developed a sizable following, seeing as the competition has largely disappeared. Used police interceptors in good condition are relatively affordable and make for a good starting point for those interested in spending time, effort and money on modifications. Because of its potential, the Crown Victoria provides great reward for those who invest in modifications, seeing big gains in performance and responsiveness.

Instructions

1. Decide if you want to go soft or deep on the modifications–soft means replacing those easy-to-reach and change parts that don’t have as much impact on the car, those that cost less but also give less. Deep means really getting in there and modifying the essentials. The former typically refers to intake, exhaust, tires and computer; the latter addresses the powertrain.

2. Begin with swapping the air intake with a cold air intake from K&N. This will net you an extra 10 to 15 horsepower on most cars.

3. Install a Flowmaster cat back exhaust system–this takes the stock 2-inch exhaust and upgrades it by at least 1/4 inch, providing the car with more air and therefore more power. Other options do exist, but the basic Flowmaster performance cat back should suffice, easily adding an extra 10 horsepower.

4. Change the rear gears. This is an excellent way to increase torque and off-the-line response, but doesn’t add horsepower. For sheer speed, this modification is a must. Go with Ford-brand 3.73s; this is what most Crown Victoria aficionados recommend.

5. Invest in so-called shorty headers once your Flowmaster exhaust is fully broken in. These performance headers create more power by allowing the engine to breathe easier and do not heat up as much as do the stock headers, resulting in less power loss. Headers are hard to install, so this may be the most expensive mod on your list until you get to the engine proper. Expect up to 20 horsepower more once this is done.

6. Look into modifying your transmission–the ones the police interceptors come with leave much to be desired. A five-speed transplant would be best, but costly and even risky. A simpler route would be to install a shift kit, such as the ones made by TransGO.

7. Install a so-called underdrive pulley, which is a crank that better uses energy to drive vehicle accessories and pumps, hence “underdrive.” It doesn’t consume as much power as do the cheaper varieties from the factory, theoretically leaving more power for the engine to use. The amount of horsepower added remains debatable.