Sorry I have not been on here much during our move
Adam, there would be NO benefit or need for larger injectors unless you are running a larger turbo and more boost. With more CFM's being pushed through your motor, more fuel is needed.
We have a customer running 16psi on a VF39 using these 440's, Wideband shows a nice 11-11.5:1 AFR. He also passes emmissions catless well within range.
These are certainly NOT large enough injectors if you want to run even larger turbo or even more boost than this. You would be approaching "ragged edge". What makes these attractive, IMO, is that they are close enough in size to the stock SS injectors, your ECU will compensate with factory ranges to make your car run like OEM. You have to realize that with a FCD in place, when the MAF signal maxes out, and the signal is clamped, the ECU essentually forces the injectors to go wide open. Finding the right boost level is up to you depending on size of turbo, your comfortable AFR and factor of safety. Intercooler, etc etc.
To be honest guys, we spend more time modifying cars, and learn through experience. I don't have vast amounts of technical detail floating around in my head like many other much more vocal members of this site and others. I try very hard to just reiterate what our experience is. I also encourage everyone to research your own project and mod to a point you are comfortable with. Also, don't believe everything you read on the internet. Budget, reliability, and fun. Find your own balance.
Also, these are SOLD!!!
Maybe I'll decide to sell my loaners when Def09 returns them, but for now, they will go back into our parts stash.