Edelbrock’s new Thunder Series AVS2 carburetors feature a new primary booster design for improved idle and cruising performance. The new “annular,” or ring-shaped, primary booster improves on the standard “downleg” booster by providing more complete atomization of fuel. Typical downleg boosters dump fuel into the center of the venturi from a single point, while the new annular booster disperses fuel from eight orifices around booster ring. Edelbrock claims the new booster design better atomizes fuel in the primary circuit, eliminating flat spots when the carburetor transitions from idle to part throttle, resulting in better low-rpm performance.

Otherwise, the AVS2 carburetor shares the same features as the rest of the Thunder Series. Carbs include provisions for timed, and full vacuum ports for ignition advance, are available with manual and electric chokes in 500, 650 and 800 CFM sizes.

310/781-2222; www.edelbrock.com.

This promotional video from Edelbrock has some great visuals to help explain how the annular booster primaries function. Be sure to check out the segment from 1:15 to 1:47 showing the difference in fuel delivery between a downleg and annular booster on a running engine.