AEM 30-6905 Universal Programmable EMS-4 User Manual
Page 20
Page 20 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
((Power x BSFC) x (1 + Safety Margin))/Number of Injectors = pounds/hour
An example of this equation is:
6 CYL. engine rated at 500 hp on gasoline using moderate boost with a 15% safety margin on
the injector
500 x .625 = 313 lbs/6 = 52 lbs/hr/ injector. 52 x 1.15=60lbs/hr/ injector
If we take the flow of the injector (60 lbs/hr) and multiply it by the number of cylinders (6), we
arrive at a total of 360 lbs/hr of flow. As you can see, the fuel pump described in the fuel pump
sizing section referenced above has enough capacity to feed the engine with a little room to
spare.
It is a good idea to know the maximum operating pressure of the fuel injectors. In some cases
the fuel injector will not open if the fuel pressure exceeds the design limit of the injector. Also, at
the higher pressures the injector fuel flow may become non-linear and cause inconsistent fuel
delivery, usually creating a lean condition. Most injectors can withstand up to 70 psi. Many of
the pintle style injectors can withstand higher pressure.
In the fuel injector sizing, always use a safety margin between 15-20%.
Harness Connections
Injector Harness Connections
Name
Wire
Wire
Color
Stamping
Injector #1
22
Orange
INJ 1
Injector #2
22
Orange
INJ 2
Injector #3
22
Orange
INJ 3
Injector #4
22
Orange
INJ 4
Fused Injector Power
14
Red
INJ POWER
INJ1
– Connect to 1
st
injector to fire.
INJ2
– Connect to 2
nd
injector to fire.
INJ3
– Connect to 3
rd
injector to fire.
INJ4
– Connect to 4
th
injector to fire.
INJ POWER
– Fused injector power. Splice required number of power leads and distribute to
each injector.