kingjas99

alright so i just got my first subi (and love it) but i will be building on it and plan and getting a slightly bigger turbo (so i dont lose to much spool time) and all the supporting mods but my question is if i get sti 740cc injectors will they be to oversized for say something like a td05 or slightly bigger turbo? and if so will it hurt my engine? thanks guys

miata_kid

You can never go to big with injectors im not saying throwing sum 1000cc would be a good idea if you dont need them but its always good to have some room just incase later you want more power you dont wanna be maxing out
Your injectors

PicovAndropov

Bigger injectors and no tune? You are dumb.

Yep4doors

I'm not flaming, I'm clearly stating that you're a dumbass and should research before you ask stupid questions. I'm sure this has been covered on NASIOC a million times now.


Edit:::

Also thanks for the grey box whoever.

Garrett93

It has.

There's even a sticky on Injectors, fuel rails, and pumps.
http://forums.nasioc.com/forums/show....php?t=1218460

kingjas99

even though that does really help answer my question

Mau5head

Google faggle

kingjas99

it had some mixed results

Fabrik8

Here's how to tell if OEM injectors are oversized: Take the power output from the engine that the injectors came from, add a little more, and that's safely the amount of power that they'll be able to handle. OEMs don't drastically oversize the injectors for the stock power output. So if an STi puts out 300ish HP, you can figure the injectors will handle somewhere above 300HP, maybe 350 to be safe and conservative. You can probably find flow numbers to tell you a really close answer. But intuitively, STi injectors should work perfectly fine because they aren't very big either. You're going from injectors on an engine with 225-ish HP to injectors on an engine with 300-ish HP, which is not a big leap. Really the only problem with getting HUGE injectors is that it's usually hard to control them at small duty cycles, so it's hard to control flow at idle and low load, part throttle. You lose resolution if you have a lot of flow and don't actually use it, because you could get a smaller injector and have better control over a wider operating range. I'll leave it up to you to research that topic further.

Because they're higher flow than your stock injectors, you will need to get retuned for the new injectors. Your ECU calibration knows what to do with the stock injector flow rate, not a larger injector with higher flow and different electromechanical characteristics. So if you change the injector flow, you have to change the ECU calibration and mapping to match.