lunar tick

iTrader: (2)

As per the title really. I'm about to bolt on an MD321H or Owen Developments turbo, either of which will produce (so I have been reassured) a genuine 400bhp

My question is will the standard injectors on an 03 UK STI be up to the job of dispensing enough fuel if I add a fuel pressure regulator, or will I need to switch to something like 650cc injectors? I've asked a few folk but have yet to get a definitive answer. Cheers in anticipation. Andrew

MartynJ

Yes Andy , they will flow enough with an adjustable reg , my personal advice though would be to uprate to 650's as this will give you extra headroom...Better to run the 650's at 80%idc than the standards flat out...

lunar tick

iTrader: (2)

Thanks Martyn - very helpful How did that mapping session go? Any dyno plots to look at??

scoobboy

iTrader: (3)

You can run 400bhp safely on 2003 sti injectors but obviously you need the adjustable reg.

I am going to be running this shortly by raising the fuel pressure from 3 bar static to 3.7 bar on my fuelab reg.

Have been told by various sources that they can run up to 440bhp, but would not risk maxing them out.

I bought a set of 650cc injectors intending to fit them, but was informed that you dont need them for 400bhp.

You could fit along with the regulator if you want and maybe inend to run more bhp, i am happy with 400bhp on my sti7 though

GazTheHat

Mine were running at 93% for 371bhp if that helps. Over 400 seems a little too close to maxed out for my liking.

lunar tick

iTrader: (2)

Thanks for help guys. Seems like 400bhp is running them pretty close to the max. Might be best to invest in some 650s to be safe. Anyone know what sort of costs are involved and how much labour is required to swap injectors??

scoobboy

iTrader: (3)

wouldnt be if the fuel pressure was raised to 3.7 bar or above though???

GazTheHat

Tell me more...

scoobboy

iTrader: (3)

ffs

Here is a quote from lateral performance when i posted requesting info on running 400bhp while on sti pinks

"STi Pink injectors are circa 505cc at standard 3bar fuel pressure, and circa 550cc at 3.5bar fuel pressure.

Depending on mod's, fuel pressure, and mapping they will give up to circa 430bhp.


Mark."

I have also spoke to Andy F and also Zen and say that you can reach 400bhp either with regulator, 650's or both running around 3.7 bar.

I decided to run the regulator just.

Obviously you need to run a hell of a lot more to acheive this and i am running the following engine mod wise:

APS SR 40 Turbo
Uprated Actuator
Walbro 255 Lt Pump
3 inch Milltek System inc 3inch up and downpipe
Wrapped Equal Length Headers
Perrin Silicone Inlet Hose
Hyperflow TMIC
APS Cast Intake with K and N in wing
AVCR Boost Controller
Tek 3 Remap by Andy F running 1.5-1.6 bar

And prob a few more mods....

But maybe you know better mate

GazTheHat

Nice! I only asked for more info on what you'd said earlier. fud.

ZEN Performance

go with 650s.

just done an STI8 with 650s, cold air induction and MD321h.

389hp on standard TMIC and standard headers, 1.4 bar at peak power, plain v-power fuel, 1 bar at 3000rpm on the road.

Paul

scoobboy

iTrader: (3)

Thats a good figure Paul, wonder what i would get mate running my setup if i was to fit a set of 650's then instead of standard pinks?

scoobboy

iTrader: (3)

thought you were being disbelieving mate, sorry

GazTheHat

Would ported standard headers be holding the setup back around 400?

ZEN Performance

400hp on Sti pinks is a push even with raised fuel pressure. I prefer to have some headroom, plus the turbo is good for a little more yet. A set of 650s costs not much more than a decent FPR fitted, but gives more power potential. They are a nice compromsie for those that don't want to run 800cc injectors, plus you can also raise the pressure on the 650s in the future if you want to go for a solid 450hp.

Upgrading pinks to 650s might not get you anything, it depends mainly whether the turbo has any more puff left in it.

Paul