Radium Engineering Drops Three “Tool-Free” Fuel Regulators to Make Pressure Adjustments Quick and Easy

Photography: Brandon Cody

  • Since 2010, Radium Engineering’s goal has been to design and produce high-quality aftermarket automotive performance products within the crucial fuel and fluid delivery subgenre.
  • Its latest invention revisits the fuel pressure regulator and introduces an industry-first “tool-free” pressure adjustment knob (with detents that “click” as it is adjusted).
  • Radium Engineering introduced three new variants: a Direct Mount Regulator (DMR-RA), Multi-Port Regulator-Rotating Assembly (MPR-RA), and a Fuel Pressure Regulator Damper-Rotating Assembly (FPRD-RA), each with its own unique benefits.
  • All RA-series regulators are suitable with all gasoline types (unleaded, leaded, oxygenated, and pre-mixes) and can also support alcohol blends of fuel including methanol, ethanol, and E85.

Sometimes, you need to break a few rules. Indeed, the bravery that often goes hand in hand with risk is a tough pill to swallow. But true innovation seldom comes with doing the same thing twice. While many are keen to accept the status quo, Radium Engineering has made a name for itself by doing the exact opposite. It’s a company that is predicated on that aforementioned courage; its products, like the motorsport fuel cells we talked about before, have propelled the world’s greatest racers across the finish line and onto the top step of the podium for over a decade. And on the street, its catch cans provide the everyday enthusiast an easy entry point to sample Radium’s engineering prowess.

Those achievements, however far-ranging, have never compelled Radium Engineering to rest on its laurels. Although its universal fuel pressure regulators have set the industry standard for some time, the Oregon-based outfit has recently sought to set even loftier expectations for this product line by integrating new features and touting improved performance to boot.


That sweeping change rests on one very important innovation: a new top cap assembly that Radium calls the “Type RA”, which is short for “rotating assembly”. 

The latest fuel pressure regulator lineup has a ground-breaking, tool-free pressure adjustment knob (with detents that “click” as it is adjusted) and a vacuum port that swivels 360° around the body for easy line routing. Every detent permits 1psi (+/-0.5psi) of adjustment depending on the current fuel pressure.

“How many times have you needed to adjust a fuel pressure regulator and you have no idea which Allen wrench size to grab, or what wrench size the adjustment screw lock nut is?” asked Aaron Suchy, co-founder of Radium Engineering. “We are the only company to introduce tool-free adjustment to the FPR market. The design is undergoing patent submission now.”

After looking at what Radium has created, it almost seemed common sense to go down this route. Suchy was spot-on with his assessment; it’s always been a guessing game for no good reason and Radium’s solution makes adjusting that pressure quick and easy. While the knob and swiveling vacuum design would’ve been satisfactory improvements to most, Suchy confessed that they also changed the internal spring and bypass orifice — made from stainless steel — for better pressure control, too.


For everyone who is already running Radium Engineering’s excellent fuel pressure regulator components, rest easy. This new top cap assembly, along with the uprated spring and orifice, can be fitted to older regulators as a convenient retrofit kit (20-1101-00). We didn’t get our hands on the conversion kit, but the fact that it exists at all is a testament to Radium’s customer-forward commitment; it had the foresight to keep the main body unchanged so that current customers could upgrade at a reasonable cost.


This all sounds incredibly exciting, but the FPR lineup was created for a very specific audience: EFI enthusiasts who have upgraded their fuel pump system where operating pressures can exceed 100psi. Radium’s aftermarket regulator is more adept at coping with the additional fuel flow being fed to the engine. Knowing that individual demands within this sub-genre can vary widely, Radium Engineering fashioned three specific solutions to accommodate the spread: a Direct-Mount regulator, a muti-port regulator, and a fuel pressure regulator damper.

All three regulator types can be used for any single-pump street applications to multi-pump race applications. Each also includes four different options for the vacuum line adapter fitting.


The Radium Direct Mount Regulator-Rotating Assembly (DMR-RA) is exactly what it sounds like: a compact, high-performance adjustable EFI fuel pressure regulator that mounts directly onto the fuel rail port. This intent means that the component would need to be small and Radium managed to achieve this: the DMR is only 3.4” at its longest dimension.

“Our direct mount regulator (DMR) is a great compliment to any of the fuel rails that we offer….and we offer over 60 fuel rail applications, more than any other company,” continued Suchy. The direct-mount solution saves space in the engine bay and reduces the number of hoses required. The DMR can also be mounted off-rail using a separate mounting kit (20-0624). 

As I mentioned earlier, RA-series regulators feature a 360° swiveling vacuum reference port that is double O-ring sealed, an industry first. It permits the installer to quickly point the vacuum fitting in any direction with no tools required. There are four interchangeable 10-32 threaded vacuum port fittings provided — barbed, 3AN male, push-to-connect, and vacuum plug — to cover all scenarios.


The Multi-Port Regulator-Rotating Assembly (MPR-RA) is a great all-in-one solution for both simple and complex high-flow fuel systems. The MPR is the original workhorse and was designed to be used pre- or post-fuel rails with plumbing flexibility in mind. That pliability comes from its unique port configuration; it can be used in single pump/rail applications by plugging the unused ports, it can combine dual fuel pumps into a single feed line, or split a single feed line into a dual bank fuel system with two fuel rails.


The Fuel Pressure Regulator Damper-Rotating Assembly (FPRD-RA) is the ultimate solution for consolidating critical fuel system components into a high-flow package. This post-rail component is a fully functional high-performance pressure regulator with a unique built-in fuel pulse damper. As such, it is ideal for systems that are experiencing a high amount of fuel pulses (from air/fuel ratio spikes, for example) and want to smooth out fuel pressure with the integrated pulse damper.


Often enough, there are components that you might as well cycle out while performing an upgrade, and that is no exception here. A pressure gauge is a good add-on to any fuel regulator purchase, so your desired pressure is available at a glance. Enthusiasts should also crucially upgrade all of the fuel lines that run to and from the regulator; a restriction-free return line is crucial for the regulator to function properly.

In the end, this suite of fuel pressure regulators is yet another example of how Radium Engineering continues to reset the bar for the segment. Like the Radium components that these have superseded, these regulators are robustly built and perform better than any other regulator on the market.