Injector Size For 400+ Hp??

CRE

7M-GE + MAFT Pro + T = :D
Oct 24, 2005
3,485
0
0
Denver, CO
440's should be sufficient, but if you're thinking of using injectors that are almost 20 years and expecting them to still flow near their original rated peak you better get them tested. I'd probably go with the 550's just so I had more headroom for later.
 

simpsons7s

Its pronounced Nu-clear..
Oct 9, 2005
253
1
0
Riverside, Ca.
A good rule of thumb is 1cc to 1hp. So if you have a 550cc injector you theoreticaly could produce 550hp at 100% duty cycle. BUT, you don't want to run your injectors past about 90% and even less of a precentage of duty cycle is better, about 85% is efficent and you will not run into any problems with injector overheating and flow restriction. So, with 440cc injectors at 85% you can safely make 374hp estimated. With 550cc you can make 467.5hp at 85%. Two things to note, first this is a "rule of thumb" there is a actual calculation behind it that you can look up to get more accuracy then this. My personal sugestion is that you get bigger injectors before hitting your threshold. Second, I know that many people have hit higher numbers than posted on these sized injectors, that depends on setup, fuel pressure, and type of injector and ecu driver, ect..