How to choose the correct injectors for your vehicle.

1st HP.
Figure out your HP(at the crankshaft),There are two ways to do this.
1.Have the vehicle dyno tested.(most accurate)
2.Get the manufacturer's advetised HP then estimate for mods done.(keep it within reason)

2nd Brake-specific fuel consumption (BSFC).
This is the amount of fuel consumed per unit of power produced.
This can also be done two ways.
1.Have the vehicle dyno tested.(most accurate)
2.Use the following.

engine type BSFC (using gasoline)
Naturally asperated 0.45(no mods)- 0.55(highly modified)
Super/Turbo charged 0.55(no mods)- 0.65(modified)

3.Safe duty cycle
This is the time that the fuel injector is open versus the total time between firing.
The safe duty cycle is 0.80(stock engines)and 0.85 (modified engines).


4.Calculate optimum injector size.
Use the info gathered and these formulas to determine the proper injector size.

___Max hp_x_BSFC____ = injector size in lbs./hr
# of injectors x duty cycle

To convert from lbs./hr to cc./min use this formula.

___lbs./hr x 60__ = cc./min
6.177

6.example
a stock 4cyl with 110hp

(110 x 0.45)divided by(4 x 0.80) = 15.4 lbs./hr

round up to next available injector size.
so this application would need a 16 lb injector.

Then

(16 x 60) divided by 6.177 = 155cc./min