Fuelab 51502 User Manual

Model Number 51502

Fuel Pressure Regulator

Operating and Installation Instructions

CCAAUUTTIIOONN!!

This product is to be installed only by persons knowledgeable in the repair and modification of vehicle fuel systems

and general vehicle systems modification. Only a qualified technician or mechanic who is aware of applicable

safety procedures should perform the installation of this product.

GASOLINE AND OTHER FUELS ARE FLAMMABLE AND CAN BE EXPLOSIVE!

Perform the installation in a well ventil ate d loc ation onl y to minim i ze the build up of fuel vapors . NO open flames,

smoking or other sources of ignition are to be present during installation, to prevent fire or explosion that can cause

serious injury or death. Grinding, cutting, and drilling must be performed with care to prevent ignition. Draining and

removal of all fuel and ventilation of vapors in vehicle and fuel system is recommended when performing such

procedures. Proper eye and personal protection is required at all times during installation.

WWAARRNNIINNGG!!

The Vehicle’s fuel system may be under pressure! Do not loosen any fuel connections until relieving all fuel system

pressure. Consult an applicable service manual for instructions to relieve fuel system pressure safely.

This product is intended for racing, off-road, or marine use only. This fuel system component is capable of altering

engine tuning and therefore not legal for sale or use on emission controlled motor vehicles.

Product Contents:

Check the diagram and list of components

Check the diagram and list of components (right) to ensure that no components are

(right) to ensure that no components are missing from box. Contact your Fuelab

missing from box. Contact your Fuelab distributor immediately for replacem ent.

distributor immediately for replacem ent.

51502 Features and Performance Ratings:

Inlet Port Sizes -6AN Military Port

Seat Size Standard

Regulation Slope 3 PSI/GPM

Maximum Flow

Capacity

Capacity Pressure

Pressure

Adjustment Range

WARNING! Exceeding maximum flow capacity may result in an over-pressure operating condition.

Before Installation, Plan Entire Fuel System:

These instructions are limited to general topics of regulator component installation and may not include specific

These instructions are limited to general topics of regulator component installation and may not include specific information pertaining to your application. These instructions are written assuming the use of an electric fuel pump

information pertaining to your application. These instructions are written assuming the use of an electric fuel pump capable of at least 100 PSIG outlet pressure and limited to the specified

capable of at least 100 PSIG outlet pressure and limited to the specified regulator has an internal spring that can be changed for other pressure ranges, including “T” range, for 10-25 PSID

regulator has an internal spring that can be changed for other pressure ranges, including “T” range, for 10-25 PSID if required by the specific application. Lower, carbureted pressure ranges are recommended for a different model of

if required by the specific application. Lower, carbureted pressure ranges are recommended for a different model of regulator only. Visit our company website for specific details pertaining to example fuel systems and other solution

regulator only. Visit our company website for specific details pertaining to example fuel systems and other solution ideas. Additional information including advanced troubleshooting, any special alerts and FAQ’s pertaining to this

ideas. Additional information including advanced troubleshooting, any special alerts and FAQ’s pertaining to this and other products is also available.

and other products is also available.

2.5 GPM at 25 PSID

(570 LPH at 1.75 Bar)

Pressure Range “E”

25-90 PSID

(1.75-6.2 Bar)

(3X) -906 O-r ing

Adjustment Screw

Plug

Jam Nut

Flat Washer

(3X) Bracket Lock Washers

Regulator

Barbed Fitting

(3X) Bracket Screws

Maximum Flow Capacity

Bracket

(above). This

General Regulator Performance Notes:

The notation “PSIG” means pressure in Pounds per Square Inch (PSI) relative to the prevailing atmospheric

The notation “PSIG” means pressure in Pounds per Square Inch (PSI) relative to the prevailing atmospheric condition or outside air. This is referred to as Gauge Pressure. The notation “PSID” means pressure in PSI relative

condition or outside air. This is referred to as Gauge Pressure. The notation “PSID” means pressure in PSI relative to another pressure source or called the Differential Pressure. The intake manifold pressure, when plumbed to the

to another pressure source or called the Differential Pressure. The intake manifold pressure, when plumbed to the regulator, changes the fuel pressure in a 1:1 ratio. When the engine idles (for example 12 Inches of Mercury or 6

regulator, changes the fuel pressure in a 1:1 ratio. When the engine idles (for example 12 Inches of Mercury or 6 PSIG of vacuum) fuel rail pressure will lower 6 PSI, when compared to the setting with the engine off. For boosted

PSIG of vacuum) fuel rail pressure will lower 6 PSI, when compared to the setting with the engine off. For boosted applications, including turbo or superchargers, fuel rail pressure increases at a 1:1 ratio. An engine at 10 PSIG of

applications, including turbo or superchargers, fuel rail pressure increases at a 1:1 ratio. An engine at 10 PSIG of boost as measured in the intake manifold, will increase the fuel pressure by 10 PSIG. The actual readings of

boost as measured in the intake manifold, will increase the fuel pressure by 10 PSIG. The actual readings of pressure in a real world application would show a lower pressure, as the engine is using fuel that would normally be

pressure in a real world application would show a lower pressure, as the engine is using fuel that would normally be returning back through the return line when the engine is off. The amount of pressure difference to expect is a

returning back through the return line when the engine is off. The amount of pressure difference to expect is a

Regulation Slop e

function of how much flow the engine is using (reference

Regulation Slop e

, above).

105020121-1, Rev A Sheet 1 of 4

Plumbing Planning Notes:

Minimize plumbing restrictions between fuel rail(s) and regulator for peak performance, use –6AN (3/8”) to –10AN

Minimize plumbing restrictions between fuel rail(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. Typical performance EFI

(5/8”) line as required per flow rate requirements of the vehicle’s engine and fuel pump. Typical performance EFI applications use a “Y” block or “T” fitting to split the output of the fuel pump into one end of each fuel rail (for dual

applications use a “Y” block or “T” fitting to split the output of the fuel pump into one end of each fuel rail (for dual fuel rail application). The opposite end of each fuel rail is plumbed to the

fuel rail application). The opposite end of each fuel rail is plumbed to the return line back to the fuel tank. Use of a –6AN (3/8”) return line is typically recommended for this model of

return line back to the fuel tank. Use of a –6AN (3/8”) 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. If only

regulator. See diagram on next page as well as diagram below, to identify the ports used on the regulator. If only one fuel rail is used for the application, use a

one fuel rail is used for the application, use a

Inlet Port

of fuel line such as stainless steel braided line and “AN” style fitting connections is recommended. The fuel ports

of fuel line such as stainless steel braided line and “AN” style fitting connections is recommended. The fuel ports (two

(two commonly used with racing and high performance applications. See step 6 on next page for additional information

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 60 micron or lower particle rating is required to be used upstream of

on this port standard. A fuel filter with a 60 micron or lower particle rating is required to be used upstream of regulator and downstream from fuel pump to protect it and the fuel injectors from foreign object damage. Referenc

regulator and downstream from fuel pump to protect it and the fuel injectors from foreign object damage. Referenc the Schematic Diagram below for filter locations. Use of a liquid filled gauge exposed to engine compartment heat

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.

is not recommended as the liquid inside the gauge may exert measurement errors. any gauge mounted inside the vehicle or in passenger compartment. A line burst can spill fuel inside passenger

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

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.

system is recommended for readings in a passenger compartment.

Typical EFI V-8 Fuel System Schematic Diagram:

Gauge may have Error Due

to Temperature Variations.

Installation Steps:

(“Y” block or “T” fitting not required in this case). The fuel line used must handle high pressure. The use

–6AN Inlet Ports

Fuel Gauge Shown in

Gauge Port, Liquid Filled

Y-Block or "T" Fitting, to Split Flow into Two

Fuel Rail System

and one

–6AN Return Port

(2X) Fuel Rails

with Injectors

Inlet Ports

–6AN plug

) use “AN” or “military” style fittings. This plumbing standard is

51502 Regulator

(not supplied) and supplied

To Engine Intake Manifold

Vented Fuel Cell or Fuel Tank.

Tank must be Plumbed According

to Maximum Pump Flow Rate.

Specifications and Recommendations .

Fuel Filter with 60 Micron or Lower Particle Rating is Required. Fuelab Filter with 6, 10 or 40 Micron Rating is Recommended.

Consult Pump Manufacturer's

Fuel Straining Filter Required, Typical

75 Micron Filter Recommended. Straining

Consult Pump Manufacturer's Specifications.

Check Valve Required f or R educed

Engine Starting. Valve may be Installed

in Fuel Pump,T ypical OEM Pumps

do have this Valve Installed. Consult

Pump Manufacturer's Specifications

Micron Rating: 75-150, Fuelab

Filter may be Installed in Fuel Pump,

Vehicle Emissions and Improved

of the regulator. Plumb the

–906 O-ring

DO NOT

Follow Fuel Cell Manufacturer's

Recommendations for Proper

Cell Vent Plumbing

High Pressure

Electric Fuel Pump

to plug the unused

plumb gauge port to

1. Disconnect the ground terminal from battery and allow the vehicle’s engine and exhaust system to cool.

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

Relieve fuel system per applicable service manual. Follow all Warnings and Cautions written on previous page of these instructions.

of these instructions.

2. Modify, remove or replace other fuel system components as required per established build plan (reference

2. Modify, remove or replace other fuel system components as required per established build plan (reference notes on previous page and above).

notes on previous page and above).

3. Use the supplied bracket as a drilling template to mark holes for mounting bracket. Choose a location that

3. Use the supplied bracket as a drilling template to mark holes for mounting bracket. Choose a location that minimizes exposure to excessive heat, near fuel rails. Mounting bracket can be modified as required. Use

minimizes exposure to excessive heat, near fuel rails. Mounting bracket can be modified as required. Use clear or colored enamel paint to protect bracket surface after any modification.

clear or colored enamel paint to protect bracket surface after any modification.

105020121-1, Rev A Sheet 2 of 4

+ 2 hidden pages

Fuelab 51502 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual