Fuel/Boost Question...

Hey guys, I’ve searched and searched and still haven’t found the answer I need. Here’s the deal…
I’m building my own kit, I’m starting with a K26 (audi Turbo, very similar to a T3). I already just about about everything i need, except for the the some Fuel elements, (Injectors, FMU,…) I already a 255lph fuel pump(in Line). I’m planning on just putting the turbo on my stock motor, it has good miles and everything…only to run 6 or so PSIs
in the mean time I’ll be building the other motor i got, same as my stock one. My question is: How do go for figuring out the type of Fuel system I need?, I mean, I’m not too sure how to calculate the amount of Fuel pressure per Pound of boost, injector size and FMU ratio. The more I read, the more confused I’ve been getting!

I’m guessing if I used DSM 450s for injectors my FMU wouldn’t need to be such a high ratio, right? Is that correct?
Would it be easier then to get some smaller injectors and use a higher ratio FMU? considering they’re easier and more convenient to find and work with…
I already have an SAFC II, it just came in the other day, I’m planning on using to help me with tunning purposes, of course.
Thanks a lot for any help! I understand this is not one of the most “smartest” questions here… :slight_smile:

either way, with the safc, you will need to tune it on the dyno, besides that, your pretty much just going to be guessing.

with the fmu setup on stock injectors, you shoudld be good for 7/8psi on stock motor. oh, fuel pump too. if you wanna make sure your rich just to be safe, use some 310cc injectors or 290cc prelude injectors. i dont think a safc is neccesary for these injectors.