BIG injectors?

[crazy1eye]

Is anyone using injectors larger than 52lb? If so, what size? What fuel rail psi? Brand?

I know the 52lb injectors can probably handle 350hp, but at what duty cycle, 100%??? With my new setup, I'm hoping to make more than 350hp & would rather be safe than sorry when it comes to the injector size, so, I'm considering 65lb or even 72lb Delphi injectors(rated @ 43.5psi). Now, there's 2 ways of doing this, 1, use the 65lb injectors at our stock 55psi, in turn making them 73lb injectors, perfect. 2, using the 72lb injectors & have the custom cal set for 43.5 fuel rail psi. But now, those 72lb injectors won't easily support 400hp because I've lowered the base fuel psi. But, I do like the fact of running a lower base fuel psi, that way, when you run 25+ boost, your fuel psi won't be 80+psi, therefor putting less strain on your fuel system.

Injector tech

I know, I know... blah, blah, blah, fuel psi... blah, blah, blah, injectors

What do you think?

Thanks

PS: Our injectors are low impudence, right?

[glhsken]

Pat,

James is looking at 72's...

With a custom cal, you could still have 55 psi base pressure. The calibration takes injector size into account and varies duty cycle. So the idle would be fine. There is 1 car I know of with that exact set-up.. of course this car likes 35 psi of boost.

yes, low

[crazy1eye]

Just remember, most injectors are sold with a flow rating @ 43.5 base fuel rail psi. So, a set of 72lb injectors would now be 81lb injectors @ 55psi... Which is OK

[glhsken]

Good point... so when the time comes to "step-up". More than likely worth a few extra $$$ to have them flowed at the pressure you intend to use.

[crazy1eye]

There's no reason to have them flowed, it's a simple calculation.

square root of new psi(55) / old psi(43.5) x old injector rate(72) = new injector rate(81).

55 / 43.5 = 1.264
sqrt of 1.264 = 1.124
1.124 x 72 = 80.96