AFIS was founded in 2012 by Harry Hruska, a pioneer in the racing industry and the founder of Precision Turbo & Engine and HPL Superior Lubricants. Hruska, who is also an NMCA Xtreme Pro Mod competitor, has spent over 30 years deeply immersed in fuel injection technology.
Troubled by the direction the fuel injector market was taking, with companies misleadingly advertising “high flow” injectors by simply increasing fuel pressure, Hruska decided it was time for a change.
“The market needed a high-flow race injector that utilized the much safer SAE standard flow rating (43.5 PSI, 3 BAR),” Hruska explained. “We felt that rating an injector at high base pressure is not only unsafe, but deceptive or confusing to the end user. We need to get back to real numbers!”
The Issue with High Base Fuel Pressures
One might wonder why some companies design their injectors around high base fuel pressures. According to Hruska, “High base pressures allow for greater flow from small injectors, making them look big when they are not. It's a game to get large flow numbers, much like taking an engine to the dyno shop that will publish the highest horsepower!” He also noted that injectors using high base pressure make it nearly impossible to use an electric fuel pump due to the extreme pressure requirements. In contrast, AFIS injectors utilize low base pressure, enabling the use of electric fuel pumps in many applications.
Redefining Reliability in Fuel Injectors
Beyond addressing pressure ratings, Hruska identified the need for more reliable high-flow injectors. “The high-flow injectors available at the time had a reputation for being unreliable or requiring frequent and costly service,” he explained. AFIS aimed to change that by offering a safer, more traditional, and reliable design that reduces the need for frequent maintenance. To further reassure customers, AFIS offers a Limited Lifetime Warranty, replacing any faulty injectors at no charge.
Engineering AFIS Injectors
Creating a superior injector begins with precise testing equipment. Before designing their injectors, Hruska and his team built a custom injector flow bench capable of handling the large fuel volumes required to test their designs.
“Designing our own flow bench was key to the success of the program,” Hruska said. “Injector flow benches capable of accurately measuring over 1000 LB/HR of flow are not commonly available. We designed and outfitted our flow bench with everything required to engineer, test, validate, and flow-match each and every injector we sell.”
The AFIS injector flow bench is an impressive piece of equipment, measuring every aspect of injector operation, including performance with different EFI systems.
“We frequently use it to measure the functionality of the injectors with different coils, ball and seat configurations, voltages, materials, driver settings, etc.,” Hruska said. “Another advantage to the flow bench is that we can overlay real-time current vs. the injector movement (open & close). This gives us an accurate picture of what the driver requirements are for each injector. We can also test the different injector drivers on the market in order to determine functionality and compatibility with AFIS injectors. This is critical for proper injector operation between different EFI systems/drivers.”
Additionally, an oscilloscope plays a crucial role in AFIS’s testing and engineering program. “The oscilloscope allows us to measure not only the function of the injector with different coils, voltages and current settings, fuel pressure, etc., but it also allows us to validate different injector driver strategies.” Hruska added that AFIS offers the flow bench services to anyone, regardless of the brand of injectors.
The AFIS High-Performance Fuel Injectors
AFIS’s latest line of High-Flow fuel injectors is available in 250, 400, 600, and 800-lb/hr flow rates, measured at 43.5 psi (3 bar). These stainless steel injectors are versatile, designed for Methanol, Ethanol, Gasoline, and CNG applications, with plans to expand into Hydrogen applications in the future.
The injectors feature one-piece construction for OEM quality and reliability, an EV1-style connector, and a low-impedance (Peak and Hold) coil. They are also flow-matched for consistent fuel delivery across all cylinders.
One of the key benefits of AFIS injectors is their ability to operate linearly at up to 95 percent duty cycle. According to Hruska, “We can confidently operate the injector at duty cycles above 80 percent without worrying about the injectors going static. On my Pro Mod, the injectors have dramatically changed (almost eliminating) the fuel corrections, not to mention the idle quality with such big injectors. We have also found that lower base pressures equal less disruption of air speed when the fuel enters the air stream. More CFM equals more HP!”
Unpredictable injector behavior can make tuning a car nearly impossible, but AFIS injectors are designed to maintain stability even at high duty cycles. “Many of the competitors’ injectors begin to go static around 80 percent duty cycle. This is also critically beneficial on an application where cylinder correction can exceed 15 percent, effectively causing some injectors to go static.”
Real-World Testing
Hruska doesn’t just test these injectors in a controlled environment; he also uses them in his own Pro Modified racing program. His C7 Corvette Pro Mod, equipped with a 526cid BAE HEMI and twin HPT 94mm turbochargers, runs on two sets of AFIS fuel injectors.
“We use AFIS 400 lb/hr primary injectors and AFIS 600 lb/hr secondary injectors, which operate at a 50psi base fuel pressure,” Hruska shared. “We use a pair of Holley external injector drivers with an FT600 ECU. We have the capability to flow over 8,000 lb/hr of fuel at 50 psi base fuel pressure, enough to easily support well over 4,500 HP on Methanol.”
Hruska’s extensive experience in Pro Modified racing directly influences the products he develops and sells. “We believe in racing what we sell, and the race program allows us to do just that. The race program has been key to the success of the injectors by allowing us to validate our results from the flow bench in a real-world application.”
For those in need of fuel injectors capable of handling high-horsepower applications, AFIS offers a range of products designed to deliver consistent, reliable performance.
Leave a comment