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INSTALLATION
The DMR should be mounted on the fuel rail outlet. The DMR inlet adapter fitting must match the fuel rail outlet port. The adapter
by itself can be installed to the fuel rail first, or the complete assembly can be installed at once.
If installing into an ORB (O-ring boss), make sure there is chamfer on the port for properly seating the O-ring. When installing an ORB
adapter, first lubricate the O-ring and then tighten it into port.
With the adapter installed in the fuel rail and the O-ring lubricated on the adapter, push the DMR onto the adapter until fully seated.
Slide the metal retaining bracket into place (reference diagram on previous page). Next, line up the bracket to the 2 mounting holes.
Apply a medium strength thread-locker to the 2 included stainless steel bolts. Secure using a 2.5mm Allen wrench.
NOTE: Once installed, the DMR can be rotated in any direction
including upside down, if required.
PLUMBING
DO NOT plumb the fuel pump feed line into one of the DMR return ports (B or C). The return line back to the fuel tank (or surge
tank) can attach to either port B or C. Plug whichever port is not used. Do not install a pressure gauge into ports B or C.
VACUUM REFERENCE
The 3/16” (5mm) vacuum barb on the regulator is used if a 1:1 vacuum reference is required. This maintains a constant ratio
between fuel pressure and intake manifold pressure for consistent fuel delivery. If the OEM pressure regulator used a vacuum hose,
route this to the barb on the DMR (5/32” ID vacuum hose is recommended). NOTE: the billet cap can be clocked to point the barb
fitting in 5 different directions. See the servicing information below for more details.
INTERCHANGEABLE ORIFICE
The DMR is equipped with an interchangeable orifice inside the regulator. This part can be easily swapped out with a different size.
These orifices have different inside flow diameters. This is required in order to match the pump(s) flow rate, fuel hose restrictions,
and targeted base static fuel pressure. The DMR comes preassembled with the “silver” orifice, which is a good match for most single
and dual pump systems. However, if multiple high flow pumps are used in a low static pressure system, the “gold” orifice can be
easily swapped in using common tools. See the servicing information below for more details.
Orifice Color
Manufacturer Rated Flow @ 43.5 psi
Silver
Factory Installed
Up to 900 LPH total fuel pump flow
Gold
Up to 1500 LPH total fuel pump flow
*These recommendations are only general suggestions to get started. Backpressure
created by return line system, operating voltage and line pressure drop will have an
influence on the final static pressure and orifice selection.
