Prev Article Next Article

A Rising Force—Testing the newest player in the centrifugal supercharger marketplace — American Forced Induction

Posted By: Evan J. Smith
A Rising Force—Testing the newest player in the centrifugal supercharger marketplace — American Forced Induction
By Thomas Anderson
Photography by Kevin DiOssi and American Forced Induction
As the world prepared to leave the 1800s and enter the 1900s-era, a new air compressing technology came into existence — centrifugal compressors. Applied in many different industrial applications, the most talked about use of this technology was in aircraft applications — until the 1924 Indianapolis 500. Joe Boyer used a centrifugally supercharged powerplant in his Duesenberg racecar to win the famed race at the Brickyard. His successful racing endeavor with this type of supercharger would set the stage for the next century of boost. 
Centrifugal air compressors changed quite a bit in the century since its Indy victory and today’s centrifugal supercharger market is booming across many disciplines of door-slammer and outlaw-style drag racing, as well as on the streets with powerful kits that are CARB-legal. The 5.0 Mustang centrifugal supercharger wars of the 1990s are often credited by many experts for the large boost of innovation, a fact we can’t ignore as the Holley NMRA Ford Nationals celebrates its 25th Anniversary season. 
The Force Awakens
Today a new name emerged, and it was created by a familiar group of product designers and hardcore horsepower enthusiasts. American Forced Induction is the brainchild of Dan and Ryan Jones along with partner Mark Brumitt. It all started when Dan and Mark began bench racing the idea of starting a company that offers replacement superchargers that drop into existing brackets and gear drives, allowing them to focus their time on creating more efficient compressors. As they developed the idea, Dan’s son, Ryan, took a strong interest in joining the group. The younger Jones grew up watching his dad design and build centrifugal superchargers, creating an interest in engineering and a foundation for this latest adventure. Ryan joined the fray nearly immediately and American Forced Induction was born. 
As you will see throughout this story, the group is already producing its street-type superchargers that come in a variety of inducer dimensions. Destined for street car/small-tire shootouts, the line-up is dubbed AF1, features a 9-inch compressor cover, and each is tagged with the impeller diameter. Right now the company offers 91mm and 94mm compressor wheels. The next step in American Force Induction’s line-up is the AF2 model with a 10.5-inch housing and 102mm impeller size. The AF2 features a standard cast-aluminum cover and a new patent-pending billet cover is slated for release this year for more power and efficiency. The AF1 and AF2 supercharger units utilize the same bolt pattern as Vortech superchargers, making these units an easy swap for existing centrifugal owners.
The AFX designation refers to the racing line-up and there are three levels of compressors with a variety of impeller sizes to fit the popular drag racing categories. Each AFX system is built using a  4.94:1 or 4.74:1 transmission step-up ratio, which is determined by the compressor size. The first step is the AFX1-91 and AFX1-94, staying with the consistent naming protocol of calling out the impeller size. These two superchargers run 9-inch compressor covers. However, American Forced Induction will produce a small run of AFX2-94 and AFX2-102 superchargers with the 10.5-inch cover for special applications that are primarily belt-driven. 
The mid-size AFX2 supercharger units (AFX2-102R, AFX2-106R, and AFX2-112R) are built using a 10.5-inch compressor cover and will be legal for categories such as X275. The AFX1 and AFX2 line offer the same bolt pattern as ProCharger P/D/F1/F2. The final steps in the AFX line-up are the AFX4-136 and AFX4-140 units and they are based on a massive 13.5-inch compressor cover, which is the common supercharger sizing found in Pro 275, Pro Modified, and other big power classes. As a note, this unit runs the same bolt pattern as the F3/F4 superchargers. 
Jones explained the AFI design strategy, “We are building transmissions that can support a significant amount of load and stress. That allows the unit to operate at a moderate duty cycle and ensure longevity.”  He expanded by saying the impeller’s max efficiency would come at a 60-percent duty cycle in popular applications and most likely 80-percent transmission duty cycle for a forthcoming Pro Mod-style blower. He casually mentioned, “We don’t want our repair department to be a profit center.”
To achieve its duty-cycle goals for each line, the company focused on a new shaft support system with tapered shafts and an assembly technique that includes what they call a “virtual shim.” It is the virtual shim that has industry insiders shaking their heads in agreement. The shim allows the supercharger assembler to have granular control of the impeller air gap during the build process. Getting the air gap set properly assists with efficiency and durability. 
Moreover, the new shaft design and support system are combined with high-quality gears, giving the AF1 and AF2 a robust transmission that remains in the street-style packaging. With the high-efficiency impeller, they peg the max impeller speed of an AF1/AF2 supercharger at a 78,000-rpm limit, far under the max limit of the transmission and fitting the 60-percent duty cycle of it. Spinning the supercharger harder won’t result in more power as it will move the impeller out of its efficiency range.
If you are wondering where to buy one, American Forced Induction is working exclusively with a dealer network. This allows shops to handle the sales and the built-in margins are a motivational source. Dan explained, “we have kept our business financially efficient so we can keep the profits, for us and our dealers, at an acceptable level, but also not be overpriced to the consumer.” Our best advice is to check the company website to track down a dealer. 
Real-World Application
We called NMRA/NMCA crew chief and noted tuner/shop owner Mike Dezotell to see the new supercharger in action. The Dez Racing speed shop finished its in-house test mule just in time for us to bolt on this supercharger. It should be of no surprise that Dez Racing built a 1986 Mustang GT with stock-style suspension for the competitive small-tire wars in the Northeast area. 
The small-block Ford combinations are a common build at Dez Racing and this one is aimed at the shop’s more aggressive, power-hungry customers. The foundation is a Dart Iron Eagle Windsor block and is 358 cubic inches, slightly smaller than their typical 427-cube Ultra Street/Renegade packages. The standard 3.500-inch stroke is found on a billet-steel crankshaft, which is paired with steel connecting rods and customs pistons (4.030 bore). The compression ratio is benign compared to today’s eighth-mile warriors with this engine bubbling at a mere 9.5:1. The camshaft is a Dez Racing custom solid-roller stick, which is standard fare for this application. 
The top-end features a pair of Trick Flow High Port cylinder cylinders, which come with a 20-degree valve angle and Total Engine Airflow is responsible for the 250cc intake runner port and other head modifications. Dezotell knew they’d be running large boost so he elected for the HIP upgrade, which stands for Hot Isostatic Pressing. It is a manufacturing process that heats the cylinder head and compresses it with 10,000 to 15,000 psi of pressure to eliminate air pockets in the casting. The result is a denser and more durable cylinder head ready for the rigors of racing. 
One look at the engine bay and it sparks nostalgia—the lower intake is a Trick Flow EFI base with a custom sheetmetal box upper. The box was more prevalent a few decades ago, however, it was on the shelf and offers enough volume for the power level. As one of Holley’s valued dealers and tuners, it is no surprise Dez Racing added a Holley EFI Dominator system to the Fox Mustang. The final noteworthy fact is the team uses VP Racing Fuels Q16 gasoline, which also requires an air-to-water intercooler that is mounted inside the cabin. 
Dezotell runs a gear-drive to turn his supercharger system and the team added a Vortech-style cover since the AF1 superchargers utilize the same bolt pattern. The group tested the AF1-94 unit to give us an idea of the power potential. We must remind everyone, the AF1 supercharger line is geared more toward the big-power street car market and the AFX models will be for the heads-up racers. Regardless of the street moniker, the supercharger was impressive with the 94mm version producing 1,110 rear-wheel horsepower at 24 psi of boost on the in-house DynoJet chassis dyno. 
“These are sporty little superchargers,” admitted Dezotell and he continued, “the unit was definitely under-spun, we use a 2.15:1 gear ratio in the drive unit and the blower has a 4.14:1 step-up ratio.” The blower speed for our testing was 71,000 at peak engine rpm and the supercharger is rated at 78,000 rpm. Despite the impeller speed, the engine still registered 24 psi of boost with the 94mm unit. It is a number that the Dez Racing crew told us was impressive for the engine package and the final chassis dyno results speak for themselves. 
Before winter, the Fox Mustang ran 5.02 at 144 mph. However, traction was less than stellar with an anemic 1.25-second 60-foot clocking and Dezotell knew there was more in the combination. He made the long drive to Bradenton Motorsports Park after the holidays for winter testing. The trip was worth it when the car ripped off a 1.13 short time to get things rolling and then stopped eighth-mile clocks in just 4.89 seconds — mission accomplished on running 4.80s with his 3,200-pound ride. The quarter-mile results were hampered due to a numerically high rear gear ratio, but Dezotell still collected a 7.63 at 173 mph time slip.
What’s next? Dezotell told us that he plans on testing the AFX-94 supercharger and he expects large gains on the chassis dyno and the drag strip. A new gear drive is being fastened to the front of the small-block Ford and he is working with American Forced Induction on the proper blower drive ratios for his combination. 
The centrifugal compressor has come a long way since its humble beginnings in the late 1800s and innovators continue to push it harder in motorsports with American Forced Induction being the latest player.   

We had the opportunity to follow Mike Dezotell’s testing of one of the first American Forced Induction superchargers on his small-tire Fox Mustang. The engine is 358ci and utilizes a pair of Trick Flow High Port heads, a unique sheetmetal upper intake, and an AF1-94 supercharger. 

Dez Racing has a DynoJet chassis dyno and it's hosted thousands of dyno pulls from a myriad of cars and combinations. It cranked 1,101 rear-wheel horsepower at 24 psi with the “street” supercharger in American Forced Induction’s new line-up. 

Here is Dezotell’s best timeslip from winter testing at Bradenton Motorsports Park. It produced over 1,100 rear-wheel horsepower and knocked off a best of 4.89 (eighth-mile) and ran out of gear before the quarter-mile, completing that distance in the 7.63 at just 173 mph. 

The AF1 and AF2 units are considered street superchargers with a max impeller speed of 78,000 rpm. This line runs the same bolt pattern as a Vortech supercharger allowing it to drop into the same brackets in either a belt- or gear-drive system.

This is the optional 10.5-inch billet cover that is available for either the AF2 or AFX2 supercharger systems. The standard cover is made from cast aluminum and also checks in at 10.5 inches. 

American Forced Induction spent considerable time designing new impeller wheels, covers, and blower transmissions. It is releasing both its street and race systems in 2023 and is currently working with racing organizations for approval. 

Here is the AFX4 being put through its paces on a test stand. The team designed a completely new transmission system and initially will offer it with two impeller diameter options: 136mm and 140mm. 

ProMedia’s Anthony Galimi (right) met with Dan Jones (left) to get a walk-through of the new AFX2 supercharger during the PRI Show this past December. 
American Forced Induction
(913) 777-8797
(866) 464-6553
Total Engine Airflow
(330) 634-2155
Trick Flow
(330) 630-1555
VP Racing
(210) 635-7744

join our

email list

You’ll be first to know about NMRA events, race results and so much more!