So Ive got my Vortec headed 355 that is around 320-330fwhp, but that's carbureted. Im putting a stealth ram on it right now.

From my maths, 24lb injectors are perfect for what i have now. If I do heads and cam, Im going to be in the 350-400hp range. The highest I am going to realistically go with this car is 450ish hp.

The white Bosch III injectors appear to be 33-34 lb injectors despite being often sold as a 36 lb injectors. They'll support anything I ever want to do with this car. But Im worried about idle quality with a batchfire EFI setup. Is a 33lb injector too big to work with what I have now? Am I better off getting the Bosch III 27lb "ls1" injectors (Which actually appear to be 24lb injectors? Maybe?) and just paying for new injectors again in a year or so when I need the bigger ones?

It appears Bosch makes or used to make some red 30lb injectors, but I am not seeing them for sale for reasonable prices anywhere.

 

I’d vote for the 36#hr
http://www.megamanual.com/v22manual/minj.htm

 

Once you get the injectors properly accounted for in the bin, the ECM will adjust the pulse width to what you need.

I'm currently running the Bosch 30 lb red injectors on my 350 at approx 400 hp. Idle's great and had fantastic all around performance. I don't think that would change if I was using 36 lb injectors and tuned for them.

 

Whichever injectors you get make sure that there is compensation data available for them.

RBob.

 

They will idle fine. I've run 80's on a 400" motor on stock ecm lol. 42's on my 383. 36's on my stock 305. Its all good once tuned

 

Agreed. I chose my Bosch 30lb's over other posible choices precisely because of the availability of voltage compensation data for that exact p/n.

 

Rbob, the white Bosch 36lb injectors are injectors I've seen you personally post data on, which is one of the big draws I have to them. I don't feel like playing games with that nonsense while learning how to tune.

the 27s are, I believe, factory ls1 injectors, so I believe the voltage offsets for those are available as well.

 

You are probably better off with the white 34#/hr injectors, as we know what the compensation data is for those. The LS1 injectors, the issue I have is that, is the compensation data truly for those injectors.

From the data sheet, here are some flow rates at different fuel pressures (skinny white injectors: 280-155-868):

Fuel Pressure: 42
Flow rate: 34.6 #/hr

Fuel Pressure: 44
Flow rate: 35.5 #/hr

Fuel Pressure: 46
Flow rate: 36.4 #/hr

RBob.