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The evolution of racing carburetors is an interesting story. Such carburetors began as humble original-equipment pieces for production cars and trucks, which forced carburetor manufacturers to compromise to keep costs in line and meet production-line demands.
To maximize the performance potentials of these OEM-style carburetors, a cottage industry of carburetor tuners and modifiers grew in the motorsports market. A leading practitioner of the black art of "rubbing" on carburetors was Barry Grant, operating out of the north Georgia mountain community of Dahlonega under the name of BG Fuel Systems. For many years, Grant's carburetors powered both weekend warriors and leading professional teams that scored major victories in drag racing, boat competitions, and stock-car, road, and off-road racing events. But Grant was not satisfied with reworking an existing carburetor into a unit that would perform at peak efficiency. "There had to be a better way," he said. The result was the Claw carburetor that he introduced in 1997.
In November 1999, Grant introduced the Demon, which, with its contemporary appearance and six patented features for improved performance, broke new ground in competition carburetors and made Demon Carburetion the third company in what is now known as Barry Grant Inc. By using the familiar modular design as the foundation for the Demon, Grant and his engineering team applied their knowledge and state-of-the-art 3-D modeling and CAD design to a clean sheet of paper. The result was a race carburetor with race-bred features passed down to the street.
DEMON DYNAMICS
Two areas of the Demon design received attention: fuel metering and air management.
The fuel-metering issue was addressed with a CNC-machined billet-aluminum metering block. Beginning with a solid block of material, metering blocks are machined to their external form, then internal passageways are machined and metering circuits are precisely drilled. Billet aluminum assured virtually no way for the metering circuit to be compromised by porosity found in some cast metering blocks. The CNC-machining process assures repeatable metering circuit parameters for consistent performance.
In the OEM environment, concern for airflow characteristics into the carburetor and through the venturi bores is not as great as it is for competition applications. For the Demon, engineers developed a patented, contoured air entry that directed incoming air into the venturi bores with minimal...