Right you clever guys.
Need to increase size of my injectors and need some feedback from someone who knows.
its a turbo V8 with low impedance injectors.
Dont want them unnecessary big, just enough for the power i am after.
So 400HP say 85% duty cycle, .65 BSFC and the kicker is the fuel pressure is 58 psi
Most injectors are flow rated at 43psi and i have seen that at 58 psi an injector should flow an extra 17%
Anyone know their way around specking an injector ??

 

you don't say what physical size you want or why you need to run 58psi but its only 50hp per cylinder. can you not get some cossie ones ?

 

So are you saying you only need injectors for 400hp ? Or are you asking something different ? And why stuck with low impedance injectors ? They're pretty uncommon these days unless you're into huge stuff, maybe 15-1600hp upwards

https://www.rcfuelinjection.com/Technical

And there's no kicker, fuel pressure will be whatever you set it at. No need to complicate a simple process.

 

you don't say what physical size you want or why you need to run 58psi but its only 50hp per cylinder. can you not get some cossie ones ?

I want to establish what flow rate first.
the regulator on the fuel rail is set at 58 and isnt adjustable other than its rising rate with the boost.


yellow Cosworth and grey Rochester, same length between rubber seals but different injector nozzle, would fit though

 

Aussie Holden V8 touring cars used Siemens 83lb 890cc low impedence injectors very succesfully for years.

 

Hi Stevie. yes only need injectors for 400-450 max as gearbox would let go with any more than that
My current injectors are low impedance and are driven by an Emerald ECU so didnt want the aggravation of changing the drivers.
Found plenty of low Impedance injectors that will physically fit (like Cossies) but its the flow rate i am looking for second opinion on.
Fuel pressure regulator is 58psi and i cant swap for an adjustable one.
Currently thinking for 400hp
8 cylinders, 85% duty cycle, .65 bsfc needs 38Lbs or 401cc (at 43psi fuel pressure.)
As i have 58psi that means the injector will flow 17% more, so reduce size by 17% 38/1.17=32.5 Lbs (341cc)
Make sense??
Also any pro's or cons with the different injector nozzles?
Ta
alan
PS. just seen your link to rcfuelinjection, .. Off to check it out

 

Thanks cossynut but i am looking to tailor the injectors to my application not just stick big ones in as they would tend to be inefficient at low revs

 

I would urge you to make sure of things. Because low impedance injectors are very uncommon these days, and fewer ecu's offer control for them also. There is no question whatsoever that Emerald would more often use high impedance injectors, which are fitted to almost everything these days and most are far superior to low impedance.
I would be surprised if Emerald would allow low impedance injectors directly.

So really...you just want some 400cc or thereabouts, but in reality as the little Siemens 600cc injectors are common as muck, very affordable and in general all round excellent, they'd be fine.

 

Thanks Stevie, will double check what i have.
Cheers
alan