Hi im lookin to upgrade my injectors on my my95 wrx atm it has the normal 380cc's but looked around and seen that most go to the sti yellows 440cc's my question is it worth goin to the 440s or maybe 550s as will the 440s be on there limit with the mods i have as i have been readin that thay might be my concern is that will the 550's be to powerfull or will thay be ok if not used to there cheers for any help

mods are

S/S headers
full decat
Apexi I/Kit
Apexi fc and commender not mapped yet tho
apexi boost contral
bigger intercooler
uprated fuel pump

 

I have a similar setup to you and I was running 90% IDC's on 550's according to the PFC commander.

440's will probably do for a td05-16g turbo but I'd suggest you also add an adjustable fuel pressure regulator to your list of mods, then if you start maxxing your injectors you can up the pressure to compensate. Also an uprated pump can overpower the OE reg, which although it can be mapped around - it isn't ideal.

If you think you will up the power in the future with a turbo upgrade, then definately go for the 550's (or more depending on your goals).

 

cheers for the info im still not sure what 2 do as i dont wanna spend out on teh wrong injectors only 2 find out i should of gone for the other ones

how easy are adjustable fuel pressure regulators 2 fit ? if so i might get one first then and fit it i dont think im gong 2 do much else 2 the car 4 now power wise

 

my car runs bigger turbo (kind of unknown spec)
apexi, uprated fuel pump, induction kit, 440cc jectors.....jectors get up to about 75% duty at 1.1bar

(and nce Ive been back to Motoscope 'll let you know what bhp it produces too!)

 

It depends on what hp you are looking for and what turbo you will be running. 440's will get you to 340hp dependant on what turbo 550's will get you to about 380ish but no injectors will do you much good without upgrading your turbo and also then getting it re-mapped

 

How are you guys getting away with that power and 440's? I have a v2 sti with the td05 and see 90%+ at 1.0 bar with the standard fuel pressure regulator? I am only putting down about 250 whp on the dyno. What am I missing?

 

They are talking about flywheel figures

 

so are the 440s not worth fittin then? i got a set and was thinkin of fittin but as im not thinkin of changein anything else yet will the 550s be 2 much or still run fine with mods i have

 

250whp is over 300bhp (closer to 320 depending on transision losses) at the flywheel that these guys are talking about. Also you've got the stock frp, which doesn't allow you to raise the base fuel pressure to give you injectors a bit more capacity...

 

If you aren't going for more power than the td05-16g then either 440's or 550's will do. Since you already have the 440's I'd fit them, the money saved by not getting the 550's could be put towards the FPR, which is easy to fit and setup.

 

ok thnaks for that adivce mate ill think thats what ill do for now then and once its mappped if mapper says there at max or anything then ill think about bigger injectors and maybe a turbo tho not sure what is next step up from the td05 16g im guessin the 18g or a diff make turbo