6 of my 8 injectors are leaking so I'm going to get new accel ones. what lbs/hr should I get? i'm building a 450hp engine plust maybe adding a supercharger also. so what would be good for that kind of engine? thanks

 

ttt

 

Inquiring minds want to know. :hail:

 

To handle 450 HP you'll need AT LEAST 30# and you'll need to bump the fuel pressure to boot.

The formula for how much HP a fuel injector can handle is:

HP = Flow# x 2 x No_Cyl x 80% Duty Cycle

The 80% is to give a "safety" as you generally should not have your fuel injectors operate much above 80% Duty Cycle. Some guys push it to 85 and even 90%, but that is not a good idea IMO. If you tried to run 30# injectors to support 450 HP, you are going to be over 95% Duty Cycle...not good.

If you go through the calcs using 30#, you will see that you actually can't support 450HP with an 80% Duty Cycle. You would need to bump up the fuel pressure quite high to get close to supporting 450 HP with 80% DC. Unfortunately, you can only go so far with fuel pressure before you start burning fuel pumps.

As I recall, the Accels are rated the same as GM - not like the SVOs which are rated lower than GM. The SVOs actually flow a little more than the GM at the standard fuel pressure.

If you are SERIOUS about supporting 450HP SAFELY (no more than 80% Duty Cycle), you really need 36#s.

And now for the BAD NEWS. Getting large high impedence injectors like those used on our cars is not that difficult. The problem is getting these large injectors to idle properly. High Impedence Injectors can only have the pulse width shorten so much before they don't work properly.

To get the pulse width short enough to handle idle with large injectors, you need to use "Peak & Hold" type injectors. Unfortunately, these injectors don't work with the factory ECM. So you have to start looking at "aftermarket DFI systems". I hope you have deep pockets.