Just considering fitting new injectors. At the moment I have 550cc,think they were from Zen Performance.

Running 1.55 bar they are showing between 89-95% duty,I thought they were capable of running more than this ?

What injectors would be ideal for me to upgrade to ? I don't want to run a great deal more boost,just have a bit more but with a lower duty cycle.

 

Anyone ?

 

What about 740cc Red Top Injectors Subaru Impreza 99-00 Flat4online.co.uk Subaru Impreza Mitsubishi Evolution EVO Walbro Fuel Pumps Injectors Intercoolers Have been looking into replacement injectors for when I do an upgrade of the Turbo, these are flow tested above 400bhp.

 

I am running 550 injectors and 423 bhp and 396 lbft so they should be fine for you although the duty cycle was 99.6 at 1.6 bar

 

Yeh,it was the duty cycle that was worrying me about mine.

Looks like the 740cc's would be more than capable for what I need.

 

I have 850s for future proof modding ....running 49% duty cycle at the mom ,460bhp

 

If you have an adjustable Fuel Pressure Reg, just increase the fuel pressure. I have 440's running @ 3.5 bar, set up by the most well known and respected mapper on here. Obviously an increase in fuel pressure will require a remap, but as would different injectors. Too many people oversize their injectors when theres simply no need.

 

I need a remap in the near future,that's why i'm looking into this issue at the moment.

I can't remember what fuel pressure i'm running,think it's 3 bar !

JGM mapped mine,tried to run 1.6 bar boost but the injectors were maxxing out so could only run 1.5 bar.

 

I wouldn't go too big then, i much prefer the injectors set at a higher fuel pressure, the throttle response is far superior. The other problem with big injectors is that they are a nightmare to get them to idle correctly, due to the low amount of fuel the engine needs on idle and the high flow capacity of the big injectors. Maybe 650's then.

 

Yeh,i'll have to check what fuel pressure i'm running and maybe raise that up abit.

Cheers

 

I got the Nismo 740cc injectors and am running around 350/360 now but as said there wanted to future proof in case i mod further some day Got them for £350 delivered!!

 

Just checked my fuel pressure and it's running at about 3 1/4 bar at idle.

Is that about right or should I raise it before getting it mapped again ?

 

i had 550cc that were in the 99%+ running 1.5bar @3.5bar pressure.

now got some zen 740cc @3.5bar and at 70%