Edelbrock 3670 User Manual - page 209

Features Available with Pro option only

209

require a table be manually calibrated for fuel pressure compensation - the Pro-Tuner

system can perform this automatically for any base pressure that you set.

In some cases, tuners decide to change overall fuel delivery by adjusting the pressure

regulator. This is not the recommended procedure, but for tuners wishing to do this or

other fuel pressure manipulation to affect global air/fuel ratio - the automatic Fuel

Correction can be disabled while still using the pressure sensor for monitoring purposes.

Fuel regulation Method: The Fuel Pressure regulator operates by referencing the

desired pressure to a base pressure. Most regulators give the user the option of

referencing to atmospheric pressure (open air), or manifold vacuum. Manifold vacuum

referencing is the recommended method; but the user may choose either method here as

well as in the setup wizard.

Low Fuel Pressure Warning Set point: When a pressure sensor is present, the Pro-

Tuner system can alert the tuner or vehicle operator of a low fuel pressure situation by

turning on the warning light. In a critical situation such as low oil pressure, Fuel

pressure, or severe fault within the system - the warning lamp will blink very rapidly. The

user can then take desired action to protect the engine or troubleshoot the fuel system.

It is recommended that your preferred setup be set during the initial programming when

the setup wizard programs your default choice into the ECU. That way, if you use the

feature to "Reset to Original User Setup", your choice will be retained. If you only set it

through the tuning screen - you will have to verify your regulation setup if you revert to

different "original" settings.

Tuning Tips:

Fuel pressure should be determined by evaluating the required flow, horsepower, and

RPM of the engine. The more pressure, the more fuel flow. The change in flow can be

calculated by the following:

Pressure vs Flow Conversion: NEW INJECTOR FLOW = SQUARE ROOT(new pressure/old

pressure) x injector rated flow

Although flow calculations and injector selection are not specifically covered in this

manual, there are many sources of that information available to the tuner. To avoid

running problems and injector/injector driver failures - the injector duty cycle should be

watched closely. As a general rule, adjust pressure to obtain a maximum of 80-85% duty

cycle of the injector with your desired air/fuel ratio. This calculation is directly displayed

on the details page for easy reference.

Run the minimum pressure required to achieve 80-85% maximum duty cycle.

This will generally be between 250 - 500 kPa (36-72 psi). Make sure you do not exceed

the recommended pressure of your fuel pump, and that the pump has adequate flow

capacity at the desired pressure. Consult your Edelbrock representative for fuel pump,

pressure, and injector recommendations.