Well I remember reading about this in the past, but cant seem to find the post now, not even on the search, so maybe u guys can help me since i need my ques answered asap as my turbo install is almost complete...

I have the vortech sfmu and plan on running 5-6.5 psi and have my 440 injectors, with tial wastegate set at 6.5. What disk, spring, ring, etc do i need to use on the SFMU at this psi level?

thanx in advance guys.

http://www.2gnt.com/www/corbin/example.html

Youre going to have to figure out your maximum fuel pressure with your relative injectors and the max boost youre planning to run. Then youre going to have to use the rising rate equation to figure out what youre rising rate will be. Then pick the disc thats the closest to that rising rate. The rising rate equation is

(maximum fuel pressure - static fuel pressure) / max boost

that is a bit of an overkill for 5-7psi on 440 cc injectors. I don't even think your idle will work out. However I imagine the disk ratio will be somethign liek 3:1

i have a very similar setup. i have the HRC 415 cc/min injectors right now i'm using the 2.72" disk (the second largest one) and the right that "fits" it. buy a bleed valve and take out a turn or two (or three, whatever works best for those injectors, don't really know) and you'll be all set. the 2.72" ring will not perfecly fit, the disk will be able to slide around a little but i've heard from numerious sources that this isn't a problem. i tried to use the "harder" spring that came with the S-FMU but so far i've had better luck with the standard silver spring that comes with it. some say that you need to order a seperate spring from vortech to get the best results.

my idle pressure is about 16 psi of fuel, and my static pressure is around 28 psi of fuel. i'm guessing that you'd be aiming for similar trims with those injectors, say maybe 15 psi at idle (yeah, i know, pretty low, but whatever) and maybe 25 psi at static. for boosted fuel trims, i found it better to just test and tune yourself and not worry about equations. i was never able to get good numbers out of corbin's equations mainly because i suck at them.