Question: What mechanism is used to power the Supercharger in Top Alcohol drar racing vehicles?

Context paragraphs:
Trans-Am production cars: Trans-Am production cars were factory-built pony cars based on vehicles raced in the Sports Car Club of America Trans-Am Series.  These cars were used largely for homologation purposes, but also as promotional tools for the series.  The first Trans-Am street car was Chevrolet's Z/28 Camaro, which entered production in 1967.  By 1970 six makes were producing street cars based on their racing vehicles.  Due to their low production numbers and high performance, these vehicles are highly collectible today.

Top Alcohol: Top Alcohol refers to two different classes in professional drag racing: Top Alcohol Dragster and the Top Alcohol Funny Car.  Commonly known as "alky" cars, both are akin in design to the premier Top Fuel classes, but less powerful (about 3500 bhp ).  In Top Alcohol Dragster, the cars used supercharged ("blown") engines, burning alcohol (methanol).  Top Alcohol Funny Cars look similar to Fuel Funny Cars, with about half the power of a Top Fuel car.  In this class only alcohol cars with three-speed transmissions are allowed.

Drug policy of Slovakia: Drug policy of Slovakia is the legislative framework that governs all aspects of legal drugs and illegal drugs on the territory of Slovakia.  It was established with the country's creation on 1 January 1993; the Slovak Republic taking over all commitments of the former Czechoslovakia.  Both domestic and international law governs the manufacture, sale, transport and use of most drugs.  Alcohol is the most used drug in Slovakia, featuring prominently in the Slovak culture.  Slovakia consistently ranks among the top alcohol consuming countries in the world.

Supercharger: A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine.  This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power.

Michael James Lewis: Michael James Lewis is an American race car driver born on December 24, 1990 in Laguna Beach, California to parents Steve Lewis (Owner of the famed Nine Racing Midget Team & former owner of Performance Racing Industry) and Loretta Lewis.  As a young, up-and-coming Race Car Driver, Michael has competed in a diverse number of racing vehicles including Formula 3, Formula BMW, Ford Focus Midgets, Touring Cars, Late Model Stock Cars, Quarter Midgets, & Go-Karts.  Michael also officially tested a Formula One car for Scuderia Ferrari F1 in the F60 chassis on November 15, 2011 (as a result from his accomplishments in Formula 3 Italia).  Michael's passion for racing is paramount and he enjoys every aspect of his racing career.  The Laguna Beach, California native is known for his professionalism, work ethic, and he lives every day for motorsport.

ANDRA Pro Series: ANDRA Pro Series is the Six Group 1 classes representing the pinnacle of Australian National Drag Racing Association (ANDRA) Championship Drag Racing these include Top Fuel, Top Doorslammer, Top Alcohol, Top Bike, Pro Stock and Pro Stock Motorcycle.  They compete across the country at venues in Western Australia, New South Wales and Queensland culminating at the championship finals at Willowbank Raceway at Ipswich in Queensland traditionally over the Queen's birthday long weekend in June.

Holman Moody: Holman-Moody was an American auto racing team, racecar manufacturer, and marine engine manufacturer.  The company currently operates out of Charlotte, North Carolina, but is no longer a race team.  Holman-Moody continues to manufacture racing vehicles using vintage parts and methods, along with special editions of modern Ford sports cars.  The race team built virtually all of the factory Ford racing vehicles of the 1950s, 1960s, and 1970s.  It owned race-cars that competed in NASCAR, drag racing, ocean boat racing, rallies, and sports car racing.  The team won NASCAR championships in 1968 and 1969 with driver David Pearson and also the 1967 Daytona 500 with Mario Andretti.  Their most recognized trademark is "Competition Proven."

Courtney Force: Courtney Force-Rahal (born June 20, 1988) is a drag racer currently competing in the NHRA.  She currently drives the Advance Auto Parts Chevy Camaro SS Funny Car for John Force Racing.  She is the youngest daughter of 16-time NHRA World Funny Car Champion John Force and his wife Laurie.  She is a graduate of Cal State Fullerton having majored in Communications.  On July 19, 2009, Courtney won her first national event in the Top Alcohol Dragster category at the 22nd annual NHRA Northwest Nationals in Seattle, Washington.  After her sister Ashley Force Hood announced her retirement from competitive racing, Courtney became the fourth driver for John Force Racing.  On July 27, 2014 Courtney passed her sister for the record of most Funny Car wins by a female driver in NHRA history.

Dirt track racing: Dirt track racing is a type of auto racing performed on clay or dirt surfaced oval tracks.  It began in the United States before World War I and became widespread during the 1920s and 1930s.  Two different types of race cars dominated—open wheel racers in the Northeast and West and stock cars in the South.  While open wheel race cars are purpose-built racing vehicles, stock cars (also known as fendered cars) can be either purpose-built race cars or street vehicles that have been modified to varying degrees.

Twincharger: Twincharger refers to a compound forced induction system used on some piston-type internal combustion engines.  It is a combination of an exhaust-driven turbocharger and an engine-driven supercharger, each mitigating the weaknesses of the other.  A belt-driven or shaft-driven supercharger offers exceptional response and low-rpm performance as it has no lag time between the application of throttle and pressurization of the manifold (assuming that it is a positive-displacement supercharger such as a Roots type or twin-screw and not a Centrifugal compressor supercharger, which does not provide boost until the engine has reached higher RPMs).  When combined with a large turbocharger — if the "turbo" was used by itself, it would offer unacceptable lag and poor response in the low-rpm range — the proper combination of the two can offer a zero-lag powerband with high torque at lower engine speeds and increased power at the higher end.  Twincharging is therefore desirable for small-displacement motors (such as VW's 1.4TSI), especially those with a large operating rpm, since they can take advantage of an artificially broad torque band over a large speed range.

Supporting paragraphs: Top Alcohol Supercharger
Answer: an air compressor that increases the pressure or density of air supplied to an internal combustion engine