Pro Modified, also known as Pro Mod, is a class or division in the sport of drag racing used in the

NHRA The National Hot Rod Association (NHRA) is a drag racing governing body, which sets rules in drag racing and hosts events all over the United States and Canada. With over 40,000 drivers in its rosters, the NHRA claims to be the largest motorsp ...

and

FIA FIA is the Fédération Internationale de l'Automobile (English: International Automobile Federation), the world's governing body for all forms of motor sport where four or more wheels are used. Fia or FIA may also refer to: People * Fia Backs ...

(quarter-mile) and the Professional Drag Racers Association (PDRA) (eighth-mile). It is similar to the

Top Doorslammer Top Doorslammer is a professional (Pro) class of Australian drag racing. It caters to full-bodied racing sedans which are replicas of Australian or US production vehicles. The class uses 514 cu. in. displacement (8.5-litre), mechanically sup ...

class as defined by the ANDRA.

Overview

NHRA Pro-Mod - Driver Stevie Fast - Bahrain 1 Racing

This division has specific rules about

engines An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power g ...

, components, bodies, etc. Pro Modifieds can either be raced on 1/4 mile or 1/8 mile tracks. Usually, the NHRA races Pro Mod cars on the 1/4 mile, resulting in high 5 to low 6 second passes, while the PDRA races strictly on 1/8 mile track setups, allowing for high 3 second-to low 4 second passes. Despite Pro Modified cars being slower than the

Top Fuel Top Fuel is a type of drag racing whose dragsters are the quickest accelerating racing cars in the world and the fastest sanctioned category of drag racing, with the fastest competitors reaching speeds of and finishing the runs in 3.62 second ...

or Funny Car classes, it has become one of the most popular divisions of the sport because of being full-bodied cars resembling Pro Stock cars with a hood scoop or superchargers being permitted. The Pro Modified class originated in the UK in 1988, and was followed in the USA by the IHRA a year later. In Europe, Pro Modified moved from the NDRS to become an FIA class in 2006. The Professional Drag Racers Association's Pro Modified classes are based on which type of boost is used (turbochargers or superchargers in Boost, while nitrous oxide is in Nitrous). Due to the near-limitless engine/

drivetrain A drivetrain (also frequently spelled as drive train or sometimes drive-train) is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components o ...

combinations and incredibly lenient rule system used by most Pro Modified racing organizations (for example, no manufacturers matching engine and body requirement), competing teams in this series of drag racing have virtually every freedom to make their car as fast and competitive as it can possibly be. Pro Mod has a rich history despite only being 30 years old, but the off season between the 2009 and 2010 seasons was the most controversial in years. The IHRA, the first sanctioning body to run the class in the USA, dropped the class in a move to focus more on

nitromethane Nitromethane, sometimes shortened to simply "nitro", is an organic compound with the chemical formula . It is the simplest organic nitro compound. It is a polar liquid commonly used as a solvent in a variety of industrial applications such as in ...

powered vehicles. Picking up where the IHRA left off, the NHRA announced that through a partnership with Get Screened America, Pro Mod would become a full-fledged professional class, running a limited schedule but still competing for national event trophies and a world champion. The winningest drivers in US Pro Modified history are Scotty Cannon, Mike Janis and Shannon Jenkins.

Engines

There are 4 different engine combinations available for the Pro Modified category. Cars utilizing forced induction via either a

turbocharger In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

, roots-type supercharger or Centrifugal-type supercharger "new starting in the 2020 season" are limited to 526 cubic inches with the turbos having a maximum inlet size of 88 millimeters. Both types of forced-induction cars must adhere to a 2,650 lb minimum weight with driver. Normally aspirated vehicles using nitrous oxide have no cubic inch limit but must weigh 2,425 lbs (1,100 kg) with the driver.

Nitrous A Nitrous Oxide Engine, or Nitrous Oxide System commonly referred to and known as NOS, is an internal combustion engine in which oxygen for burning the fuel comes from the decomposition of nitrous oxide, N2O, rather than air. The system incre ...

cars use high octane racing gasoline as fuel while supercharged and turbo cars use methanol as 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.The

exhaust system An exhaust system is used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall syste ...

is similar to that of a Funny Car. Simple short header pipes bolted onto the

engine block In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attac ...

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 A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...

on the heads has its own individual pipe, but in the case of turbocharged engines the four pipes on each side of the

converge into one single pipe which then leads into one of the two

s, as Pro Mod engines are almost exclusively charged by one turbocharger on each side of the motor (one turbocharger for each four cylinders), resulting in two exhaust pipes instead of eight. On November 4th 2019, the

announced the inclusion of the 526ci Centrifugal supercharger as well as the 960ci nitrous injected combinations. Those will be legal for competition as of the first race of the 2020 season.

Bodies

The body of a Pro Modified car is somewhat similar to a Pro Stock race car, yet also radically different at the same time. Whereas Pro Stock cars retain street identification, Pro Modified cars' bodies are just that: modified. Pro Mod race cars have either a forward-facing (with the opening in front)

hood scoop A hood scoop (North American English) or bonnet scoop (Commonwealth English), sometimes called bonnet airdam and air dam, is an upraised component on the hood of a motor vehicle that either allows a flow of air to directly enter the engine co ...

for

nitrous A Nitrous Oxide Engine, or Nitrous Oxide System commonly referred to and known as NOS, is an internal combustion engine in which oxygen for burning the fuel comes from the decomposition of nitrous oxide, N2O, rather than air. The system incre ...

injected cars, or the hood may be cut to allow a supercharger to be fitted through onto a blown motor. Also, a Pro Modified car is usually fitted with a long, flat wing extending from the base of the rear

windshield The windshield (North American English) or windscreen (Commonwealth English) of an aircraft, car, bus, motorbike, truck, train, boat or streetcar is the front window, which provides visibility while protecting occupants from the elements. ...

and past where the lip of the trunk lid would be on a normal car. This wing aids in

downforce Downforce is a downwards lift force created by the aerodynamic features of a vehicle. If the vehicle is a car, the purpose of downforce is to allow the car to travel faster by increasing the vertical force on the tires, thus creating more grip ...

and

stability Stability may refer to: Mathematics *Stability theory, the study of the stability of solutions to differential equations and dynamical systems ** Asymptotic stability ** Linear stability ** Lyapunov stability ** Orbital stability ** Structural sta ...

, and helps keep the car on the ground. Many body styles are represented in the Pro Mod class. Everything from a

Plymouth Superbird The Plymouth Superbird is a highly modified, short-lived version of the Plymouth Road Runner with applied graphic images as well as a distinctive horn sound both referencing the popular ''Looney Tunes'' cartoon character the Road Runner. It was ...

to a

Volkswagen Beetle The Volkswagen Beetle—officially the Volkswagen Type 1, informally in German (meaning "beetle"), in parts of the English-speaking world the Bug, and known by many other nicknames in other languages—is a two-door, rear-engine economy car, ...

has been seen at the dragstrip in Pro Mod fitting. Some of the more common body styles include the

Chevrolet Corvette The Chevrolet Corvette is a two-door, two-passenger luxury sports car manufactured and marketed by Chevrolet since 1953. With eight design generations, noted sequentially from C1 to C8, the Corvette is noted for its performance and distinctiv ...

and

Camaro The Chevrolet Camaro is a mid-size American automobile manufactured by Chevrolet, classified as a pony car. It first went on sale on September 29, 1966, for the 1967 model year and was designed to compete with the Ford Mustang. The Camaro share ...

, the Ford Mustang, and Studebaker vehicles. Small pick-up trucks, like the Chevrolet S-10 also make for popular Pro Mod vehicle choices. The material with which the body of a Pro Modified race car is constructed out of is a Carbon Fiber or similar composites, similar to the material used in the bodies of most race cars. In 2008, the IHRA banned any body style of a current legal Pro Stock car (

Chevrolet Cobalt The Chevrolet Cobalt is a compact car introduced by Chevrolet in 2004 for the 2005 model year. The Cobalt replaced both the Cavalier and the Toyota-based Geo/Chevrolet Prizm as Chevrolet's compact car. The Cobalt was available as both a coupe ...

Dodge Stratus The Dodge Stratus is a mid-size car that was introduced by Dodge in December 1994 and was based on the 4-door sedan Chrysler JA platform. The Stratus, Plymouth Breeze, and Chrysler Cirrus were all on ''Car and Driver'' magazine's Ten Best li ...

, or Ford Mustang, Holden Commodore, or the former Pontiac G6 GXP) from being used in Pro Modified, but that rule disappeared when the IHRA ceased sanction of the class. Any legal body style is permitted in NHRA or PDRA sanctioned races, with former NHRA Pro Stock Motorcycle champion Matt Smith racing his father's (Trickie Rickie Smith's) 2010-style Chevrolet Camaro at the 2011 U. S. Nationals.

References

{{Class of Auto racing Drag racing classes

Overview

Engines

Bodies

See also

References