Inside The Billet Atomizer 4: Taking Fuel Delivery To A New Level


Nothing stays static in drag racing. It has always been a motorsport that’s in a constant state of growth and progression. Since the first two cars lined up to see who was quicker, racers have always looked for ways to gain an edge while pushing the technology of racing further. As the years have passed, new technology in street cars has bled into the aftermarket for cars, and been weaponized for racing. One of the biggest developments in street cars has been electronic fuel injection, and that has found its way to the track in drag racing.


The Atomizer 4 brings new meaning to the phrase “size matters”….

Jack French and his company, Atomizer Fuel Systems Inc., have been driving the fuel injection movement in drag racing for years with their Atomizer line of fuel injectors. Their newest product, the Atomizer 4, is about to change the way fuel is delivered into high horsepower engines across the drag racing landscape.

Fuel Injection And Drag Racing

All fuel injectors work based on the simple idea of introducing fuel into the combustion process, but they function in a complex way. The injectors are really nothing more than a tight tolerance solenoid valve that opens and closes when commanded by the ECU. These injectors are calibrated to deliver a specific dosage of fuel per the horsepower and air/fuel requirements of the engine.

Mechanical Fuel Injection vs Electronic Fuel Injection

Many blower cars still use a mechanical-style fuel injection system to introduce whatever type of fuel they are running into the engine. Jack explains the big difference between mechanical fuel injection systems vs EFI fuel injection systems: “Mechanical fuel injection is nothing more than a jetted application that just sprays fuel all the time. The fuel flow increases as the engine RPM increases with the fuel pump turning faster and so forth. With the EFI you have a high level of command and control over the fuel mixture that goes in the motor. You’re only adding what you need and not wasting fuel or wearing the cylinder walls out or damaging the rings.”

Things like pulse width, duty cycle, and flow rate all play a part in how long the injector is open, how much fuel will flow, and how much pressure is behind that flow. The OEM injectors in your typical street car operate based on these functions, but high performance drag racing injectors do it on a much grander scale.

Jack has spent years with Atomizer Fuel Systems making injectors that can withstand the rigors of drag racing, and he knows what it takes for these units to perform at a high level. “To be able to deliver fuel in a reliable and accurate way each cycle, you have to have bigger internal components than a standard OEM injector.

“When you have the bigger parts to flow the fuel, you have to have bigger electro-magnetic parts inside the injector for it to function correctly. The coil of the injector is bigger, and everything has to be scaled up to match. When you start scaling things up, your enemy is friction. The tolerances are tighter inside with high horsepower injectors to help minimize friction internally, and help the injectors function better,” Jack explains.

The injectors that are used in drag racing have much tighter tolerances than any OEM injector. These units have lots of polished surfaces internally that have been precision-ground and hand-fitted. These processes are used to make sure they have as little friction as possible while functioning under extreme conditions.  The materials used on units from companies like Atomizer Fuel Systems are military spec magnetic alloys that are proprietary — much better than OEM — and are used in things from fighter planes to submarines. Quality materials like these help to fight the effects of the potent and corrosive fuels used in drag racing.

 The Atomizer 3 Paves The Way

To aid in making fuel injection a viable option for drag racing, there needed to be parts that could perform at the level desired. Jack developed the Atomizer 3 injector as the first and only purpose-built drag racing fuel injector in the world. It was the first and only injector that could be purposely tailored to meet a specific application for racers based on their engine combination.


The design of the Atomizer 3 revolutionized fuel injection in drag racing. This injector allowed racers to have custom control over their fueling needs.

“The Atomizer 3 has a range of flow rates, from 40 lbs/hour to 800 lbs/hour, good idle capability and can be customized for a specific combination for a racer. That’s really the best feature of the Atomizer 3. It’s a specific built race piece, no matter if you’re making 1,100 horsepower or 4,500. We can put you in that correct duty cycle range, and target your injectors to be where they need to be. If you have something that’s application-specific, like nitrous, we can do the math and find the exact injector size you need, and make the injector optimize that power-adder. The Atomizer 3 can have the correct duty cycle calibrated to the application, based on injector size to match the ideal 65-70 perecent range,” Jack says.


A variation of the Atomizer 3 has even been created to work with radical combinations, including cars that use screw blowers as power-adders. These injectors feature an innovative design that has several patents pending, a male -4 AN fitting on the top, and have swivel -6 ORB fittings on the bottom for different applications. This allows a diverse use of the injector, and great fueling control for a blower car that lets them use new EFI technology for the first time ever.

moore orb plumbing

Here you can see just how the Atomizer 3 blower injectors can be used on an intake.

“We have designed these to where you can actually hook a hose up to the top of them, and you don’t even need a fuel rail. That ability makes them very diverse in how they can be used in different situations.  All of this is stuff that nobody has done, and we have them out there in cars right now. Tom Bailey’s Camaro has this blower-style injector, and they have the hoses running into the top of each injector. The injectors are screwed right into the manifold into the runner, so a car has no fuel rails at all,” Jack explains.

Big Power Needs A Big Injector: The Billet Atomizer 4

As fuel injection technology has progressed in drag racing, so has horsepower and the need to generate more at the track. The Atomizer 3 is a great injector, but something bigger was needed to provide the ability to make really big power in the future. “We want to continue to develop the drag racing fuel injector for higher-horsepower applications. Our goal is to put electronic fuel injection technology in every class of drag racing. The Atomizer 4 is designed to move lots of fuel for big power applications with any type of supercharger or turbocharger that can be used,” Jack says.


Jack went to his magical drawing board and began devising an entirely new injector that would be able to flow a high volume of fuel — more than any other injector before. “This injector was conceived in my head to offer a single injector delivery system for whatever horsepower and fuel combination that the end user would want to attempt,” Jack explains.

Many racers are forced to use dual injectors in boosted applications because there hasn’t been a single injector that could move enough fuel before the Atomizer 4. “The advantage to having a single injector over a dual injector setup is that if you have some type of failure in terms of an injector driver, wiring issue, or the injector itself on one of the two injectors, you won’t lean that cylinder out and cause catastrophic engine damage because of that lean condition,” Jack says.

The parts inside the Atomizer 4 are made from military grade materials to ensure they function at the highest level.

In addition to having a lower possibility of engine damage due to an injector failure on a dual setup, a single injector will also be more efficient with fuel. By not pumping unneeded fuel into a cylinder, maintenance and premature engine wear will be reduced significantly.

One of the biggest features on these new Atomizer 4 injectors is that they have more than triple the number of atomization holes versus the Atomizer 3 units — 205 orifices to be exact. Jack went this route with the new injector’s atomization disc to help ensure that the fuel would vaporize at max capacity, burn efficiently, and give tuners the control they need to keep the car happy. The injectors feature a design that allows them to be rebuilt when needed, and are totally O-ring free.

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Here you can see just how much bigger the Atomizer 4 is compared to the Atomizer 3.

Since these injectors are so much larger than the standard injector, a much bigger coil had to be used inside. The .47 ohm coil uses over a quarter pound of 18 gauge wire in each injector, but the injector only weighs slightly more than the Atomizer 3. This resistance level allows the Atomizer 4 to have a much faster saturation rate when it fires.

The size of the injectors plays a role in just how much fuel pressure is needed to make them function and achieve the correct operational range. “These will work within the same fuel pressure range as the Atomizer 3. The base fuel range will be at 90 psi, and will run up to around 165 psi max. I really don’t think you’ll need that much pressure to get the flow they require because the Atomizer 4 is a different animal dynamically than any other injector. The Atomizer 4 should be able to deliver as much fuel as you could ever need at around 130 psi,” Jack says.

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The final flow rates that for the Atomizer 4 will be in the 800 to 1,500 pph range. Those types of flow numbers will allow the Atomizer 4 to fuel just about any type of high horsepower combination out there, no matter what fuel it runs on. It will also remove the need to have dual injectors in most boosted applications that racers use today.


The Atomizer 4 will require different fuel rails to fit on most intakes used today in drag racing.

Due to their large size, these injectors require some special provisions to be made on the intake side of things. Jack has already been working with several of the top induction companies on getting intakes designed, and has a working unit from Visnor Engine Development that has been used on Anthony DiSomma’s Mustang in testing.

“One of the challenges is with the fuel rails that will be required with these injectors because they’re enormous. Most people use extruded fuel rails and their -12 fittings on the end, which will be too small for this injector. It will require a custom fuel rail that’s made of billet material to start with, then people might develop some extruded units,” Jack says. There’s a plan to also offer matching billet fuel rails directly from Atomizer Fuel Systems as part of the Atomizer 4 package.

Jack and his team are also working directly with all the top ECU manufacturers to help make sure the Atomizer 4 injectors work flawlessly for the end users. “These injectors will work fine with any of the current 8 amp peak, 2 amp hold drivers inside the ECUs that are out there currently. We’ve been collaborating closely with FuelTech on optimizing the driving system for the injector. They have been great to work with, and have sent us custom drivers so we can improve the injectors,” Jack says.

Development And Theory Meets The Track

Embarking on a venture to develop a product like this is no easy task. Jack and his team spent long hours developing this new Atomizer 4 injector, along with investing a considerable amount of money to make the first prototypes. All of that hard work and sacrifice paid off for Jack when the injectors saw their first action in DiSomma’s car. “We were pleasantly surprised with the data, and we’re just very happy overall with this new injector. The first testing of these was a success in our eyes. We went down the track, the injectors idled, they spooled, and we made lots of power as needed,” Jack explains.

Video Credit: TheRacingVids

The injector, due to its sheer size, is slower to open than the Atomizer 3, at 3.1 milliseconds of dead time. Jack will have a new coil design in the final injectors that will knock that dead time down to the 2.1 to 2.5 millisecond range. The on-car testing provided great data, and showed the performance of the Atomizer 4 was exactly what Jack hoped for. He said, “When the car was making power going down track, the results have been great. It showed the injectors were performing very clean down track and only at 60 percent duty cycle, 32 pounds of boost at 65 psi fuel pressure while flowing 1,200 lbs/hour static flow. The ideal target we’re looking for is the injectors to be at 70 percent duty cycle and 110 psi of fuel pressure, so we’re really close to where we need to be.”

What these numbers mean is that the Atomizer 4 can move the required amounts of fuel needed for the highest of power applications at a lower psi, due to the size of the injector. These flow and fuel pressure numbers reinforce Jack’s idea that this single, large injector can flow enough fuel to replace the need for two injector system many used today. “We can control this injector much better at the higher power levels, and it makes it easier to flow huge amounts of fuel to make big power,” Jack says.

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The goal for Jack is to bring the technology of the Atomizer 4 to its baby brother the Atomizer 3 in future designs.

All of this data would not be possible without the help of a few key people.

“Anthony DiSomma and the Bruder brothers have been huge in this process. Anthony allowed us to use his equipment as a test bed for a new technology, and the Bruder brothers have been instrumental in the tuning process with their knowledge,” Jack says.

Jack’s plan for the Atomizer 4 is to use the data gathered during testing and continue to refine the final product more before production, but there is a larger plan in play. “We want to start incorporating this design into future injectors, no matter the size. With the current smaller injectors, you can’t take the coil off and put it back on. This new injector has that built in, and we want to incorporate that going forward. Hopefully, this design can be utilized across the board to offer a single injector per-cylinder for any horsepower range and fuel type,” Jack explains.

The Atomizer 4 injector is literally and figuratively a huge development for fuel injection technology in drag racing. This new injector will allow racers to use EFI on more powerful applications, while ending the need for dual injector setups, which can cause catastrophic and dangerous engine disasters if one of the injectors fails. Through creative thought, Jack has developed a product in the Atomizer 4 that will impact engine management and maintenance in a positive way that will help make racecars even faster in the future.

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About the author

Brian Wagner

Spending his childhood at different race tracks around Ohio with his family’s 1967 Nova, Brian developed a true love for drag racing. When Brian is not writing, you can find him at the track as a crew chief, doing freelance photography, or beating on his nitrous-fed 2000 Trans Am.
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