injector sizing

[92tsi123]

yes, and pulse width, ummm. thats how long they are on for, which is programed into the ecu, by the manufacture.

Also, Duty Cycle isn't controlled by anything, it's just a percentage figured out by Pulse Width...

 

[92tsi123]

yeah, i looked at those, they are nice maps, i think ill play around with it tomarrow at school. ill see if it works good with a stronger pump.

Fuel pump rewire:
http://www.plymouthlaser.com/rewire.htm
http://www.vfaq.com/mods/pump-relay.html

Now, how are you able to know that you can run 12.9 if you refuse to go to the track?

 

[sweet97]

Why is it that my 550cc injectors were at 100% duty cycle and when I switched to 720's the DC dropped dramatically? i can understand that the ECU controls DC but wouldn't the ECU do that by info it was receiving?

 

[92redman]

Why is it that my 550cc injectors were at 100% duty cycle and when I switched to 720's the DC dropped dramatically? i can understand that the ECU controls DC but wouldn't the ECU do that by info it was receiving?

As I stated above, duty cycle is % on time for the injector.

Duty cycle is not directly controlled, but rather a result of injector pulse width which is controlled by a preprogrammed map based upon several inputs. Obviously using larger injectors means you will have to lower the pulse width(therefore duty cycle) to inject the same volume of fuel.