Jeff Smith Reviews the New Edelbrock AVS2 Performance Carburetor What Is an Annular Flow Booster and Why Is It Superior to Down-Leg Boosters?

The AVS2 Series four-barrel is Edelbrock’s latest generation of performance carburetor that was first introduced at the 2017 SEMA Show in 500cfm and 650cfm versions for small cubic-inch and dual-quad applications. We followed up this year with a new 800cfm AVS2 that provides optimum performance for high-horsepower applications on both small- and big-block engine applications.

AVS2 annular booster ring

The typical downleg boosters (left) are located in the carburetor primaries and simply provide fuel down the center of the venturi. The AVS2 Annular Boosters (right) feature a ring with eight equally spaced orifices for better fuel atomization. The improved fuel atomization eliminates flat spots when the carburetor transitions from idle to part throttle for better low rpm performance. The annular boosters can also provide improved mileage in some applications.

Edelbrock AVS2 annular-flow booster ring

A close-up look at the AVS2 Annular Flow Booster shows the red-anodized ring with eight equally spaced orifices for improved fuel atomization.

All AVS2 Series carburetors feature the innovative annular-flow booster ring that replaces the standard down-leg booster used in most other carburetors. So how can a small booster ring make such a huge improvement in performance? To answer that question, we could unload all the technical talk from the guys at Edelbrock who developed the AVS2, but for an unbiased explanation of how the AVS2 works we tracked down two guys who not only are experts in their respective fields but also have first-hand experience with all types of performance carbs.

First is NHRA drag racer Steve Wann who most recently capped off the 2018 drag racing season with a Super Stock victory at the NHRA Finals at Pomona. Capturing a national event Wally is no simple task and Wann credits the improved performance and consistency in the familiar white-on-blue “Mr. 413” 1962 Plymouth Sport Fury to his dual Edelbrock carbs equipped with Annular Flow Boosters.

2018 NHRA Finals Super Stock winner

2018 NHRA Finals Super Stock champion Steve Wann powering his 1962 Plymouth Sport Fury to a national event victory with a pair of Edelbrock carbs featuring Annular Flow Booster Rings.

Wann said, “They were worth almost 10 horsepower on the dyno when I was in Bowling Green, Kentucky. I tested on Monday and they were .400 to .500 quicker than my other carburetors. I tested again and did a back-to-back at Indy and had the same results. They also made the car a lot more consistent on ETs.”

edelbrock carburetor, giveaway

The Edelbrock AVS2 Series Carburetor is available in 500cfm, 650cfm, and now 800cfm for high-horsepower applications.

For a more technical review of the Edelbrock AVS2 Series carburetor, we have none other than Jeff Smith. Jeff, as you know, is a long-time automotive journalist and former editor of Hot Rod and Car Craft, and his expertise on high-performance engine building is second to none. To hear what Jeff thinks about the AVS2 Series carburetor with the Annular Flow Booster, play the video above. For more on Edelbrock carburetors, visit our website at