Pro Modified - Engines

Engines

There are 4 different engine combinations available for the Pro Modified category. A car utilizing a supercharger as its power adder is limited to 526 cubic inches and must have a minimum weight of 2,650 lbs with the driver. Cars utilizing turbochargers as a power adder are limited to 540 cubic inches with the turbochargers having a maximum size of 88 millimeters each. They too must adhere to the same 2,650 lb minimum weight with driver as the supercharged vehicles. Currently vehicles using nitrous oxide have no cubic inch limit but must weigh 2,425 lbs with the driver. Both nitrous and turbocharged cars use high octane racing gasoline as fuel while supercharged cars use methanol as a fuel.

These engines put out an extremely large amount of horsepower, some at approximately 2500 to upwards of 4000 H.P. The engines propel the cars down the track at speeds of over 250 mph. Most supercharged engines are based on Chrysler's 426 Hemi engine. The exhaust system is similar to that of a Funny Car. Simple short header pipes bolted onto the engine block heads extend down from the motor and curve upward just before reaching the ground. The exhaust pipes are visible just behind the front wheels of the vehicle. Most of the time, each exhaust port on the heads has its own individual pipe, but occasionally the four pipes on each side of the engine block converge into one single header collector on each side of the motor, resulting in two exhaust pipes instead of eight.