Radium Engineering Adjustable Fuel Pressure Regulator (MPR-RA) Multi-Port Regulator Radium Engineering

The Multi-Port Regulator-Rotating Assembly (MPR-RA) is a great solution for both simple and complex high-flow fuel systems. Its unique port configuration makes it ideal for combining dual fuel pumps into a single feed line. Conversely, it can be used to split a single feed line to a dual bank fuel system with 2 fuel rails. In additon, it can also be used for single pump or single fuel rail applications by simply plugging the unused ports. 

---

MOUNTING
There are many unique ways to mount this regulator. For example, wall mounting can be accomplished by using the M6 holes that pass through the regulator body or the included mounting bracket (shown below) can be used for floor mounting. M6x1mm hardware is provided.

---

PLUMBING
This regulator can be plumbed many different ways to suit various installations, such as traditional flow-through or dead-head systems. Because of this flexibility, it eliminates the need for an extra “Y” fitting. The lower 2 opposing return ports are unique in that they flow parallel with the pressure ports eliminating the need for elbow fittings. Either lower port can be used for the return line. Plug(s) are provided for unused ports. 

---

FUEL PRESSURE ADJUSTMENT
RA-series regulators feature the first tool-less pressure adjustment. A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased. 

To aid in adjusting pressure, there are incremental detents that provide haptic feedback to the user. Every detent permits 1psi (+/-0.5psi) of adjustment depending on current fuel pressure.

---

FUEL PRESSURE STABILITY
With years of track and bench testing data, the RA-series regulators have been refined to optimize pressure management. A newly designed single stainless steel return orifice generates laminar flow that enhances stability control.

Minimum Pressure: 18.5psi (1.3bar)
Maximum Pressure: *N/A
*This is rhetorical. The maximum pressure is dependent on the relief valve inside the pump or the maximum current the fuel pump controller allows. 

---

1:1 RISING RATE VACUUM REFERENCE
RA-series regulators feature a 360 degree swiveling vacuum reference port that is double O-ring sealed. This is the first in the industry. It permits the installer to quickly point the vacuum fitting in any direction with no tools required.

There are 4 interchangeable 10-32 threaded vacuum port fittings provided to cover all scenarios. 

1. Barbed Fitting: A black zinc-plated 3/16″ (5mm) barb machined from high strength steel that is compatible with the following vacuum hoses: 5/32″ (4mm), 3/16″ (5mm), and 7/32″ (6mm).
2. 3AN Male Fitting: A black zinc-plated adapter machined from high strength steel that is compatible with 3AN hose ends.
3. Push-To-Connect: A nickel-plated brass fitting with Buna-N O-rings that is compatible with hard plastic 1/4″ OD tubing.
4. Vacuum Plug: A black oxide stainless steel screw that is used to maintain a constant (non dynamic) fuel pressure. Beginning in the mid 1990s, vehicle manufacturers started transitioning to returnless fuel systems to lower EVAP emissions. To keep temperatures lower, these regulators are mounted inside the tank and do NOT have the ability to be vacuum referenced. This plug would be required in this scenario.

NOTE: When installing the vacuum fitting, it is recommended to use a wicking medium-strength threadlocker.

---

FUEL COMPATIBILITY
All RA-series regulators are suitable with all gasoline types including unleaded, leaded, oxygenated, and pre-mixes. Furthermore, they are compatible with alcohol blends of fuel including methanol, ethanol, and E85. 

---

INCLUDED
-Main Rotating Assembly
-Mounting Bracket with Hardware
-5mm Barbed Vacuum Fitting
-Vacuum Plug Fitting (Returnless)
-1/4″ Push-To-Connect Vacuum Fitting
-3AN Male Vacuum Fitting
-6AN ORB plug (x2)
-8AN ORB plug (x1)
-6AN ORB to 6AN male adapter (x3)
-8AN ORB to 8AN male adapter (x1)