Fuelab 52502 Fuel Pressure Regulator - Manual (Page 2)

Fuel Gauge Shown in
Gauge Port, Liquid Filled
Gauge may have Error Due
to Temperature Variations.
52502 Regulator
To Induction Tube (for Blow-
Through Applications Only!
Otherwise Do Not Plumb or Plug)
Inlet Port on Left Side
Return Port on Right Side
Use Y-Block, Fuel Log
or T-Fitting to Split
Flow to Carburetor
Vented Fuel Cell or Fuel Tank.
Tank must be Plumbed According
to Maximum Pump Flow Rate.
Consult Pump Manufacturer's
Specifications and Recommendations.
Follow Fuel Cell Manufacturer's
Recommendations for Proper
Cell Vent Plumbing
Fuel Straining Filter Required, Typical
Micron Rating: 75-150, Fuelab
75 Micron Filter Recommended. Straining
Filter may be Installed in Fuel Pump,
Consult Pump Manufacturer's Specifications.
105020203-1, No Rev Page 2 of 4
Fuel Pump
Fuelab Prodigy Series
Fuel Pump Recommended.
Fuel Filter with 60 Micron or
Lower Particle Rating is Required.
Fuelab Filter with 6, 10 or 40
Micron Rating is Recommended.
Plumbing Planning Notes:
Minimize plumbing restrictions between carburetor(s) and regulator for peak performance. Use –6AN (3/8”) to
–10AN (5/8”) line as required per flow rate requirements of the vehicle’s engine and fuel pump. See company web-
site for nitrous oxide use and alternate plumbing schematics. Plumb the return line back to the fuel tank. Use of a
–8AN (1/2”) return line is typically recommended for this model of regulator. See diagram on next page as well as
diagram below, to identify the ports used on the regulator. Pressure is relieved from the regulator out to the rest of
the fuel system, by returning unused fuel back to the fuel cell. Use a “T” or “Y” Block fitting to allow fuel to be feed
into carburetor prior to plumbing to fuel pressure regulator (see diagram below). Plumb the Pressure Reference
Port using the barbed fitting for “blow-through” carbureted applications only, “blow-through” means that a turbo or
supercharger is used to pressurize the carburetor(s). When this occurs, fuel pressure must be compensated by the
change in float bowl pressure. If motor is naturally aspirated (Normal carbureted application, with float bowl vented
to atmosphere) allow this port to vent to atmosphere, do not plug or plumb to any pressure source. The fuel line
used must handle high pressure. The use of fuel line such as stainless steel braided line and “AN” style fitting
connections is recommended. The fuel ports (one –6AN Inlet Port and one –6AN Return Port) use “AN” or “military”
style fittings. This plumbing standard is commonly used with racing and high performance applications. See step 6
on next page for additional information on this port standard. A fuel filter with a 40 micron or lower particle rating is
required to be used upstream of regulator and downstream from fuel pump to protect it and the carburetor from
foreign object damage. Reference the Schematic Diagram below for filter locations. Use of a liquid filled gauge
exposed to engine compartment heat is not recommended as the liquid inside the gauge may exert measurement
errors. DO NOT plumb gauge port to any gauge mounted inside the vehicle or in passenger compartment. A line
burst can spill fuel inside passenger compartment and on occupants, possibly causing serious injury or death. An
electric gauge or pressure transducer system is recommended for readings in a passenger compartment.
Typical Carbureted Fuel System Schematic Diagram:
Installation Steps:
1. Disconnect the ground terminal from battery and allow the vehicle’s engine and exhaust system to cool.
Relieve fuel system per applicable service manual. Follow all Warnings and Cautions written on previous page
of these instructions.
2. Modify, remove or replace other fuel system components as required per established build plan (reference
notes on previous page and above).