Injectors + Tune>?

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Hey, so my injectors are leaking pretty bad, car always reeks of fresh gas...

I can't decide (cost purposes) what is more beneficial.

Should I upgrade them to a bigger size and get and ecu and tune?
I'm not looking to run crazy power, i do have fully forged internals and upgraded HKS turbos,

*Main question: If i up my injectors and get a tune, how much should I expect to pay and will it burn massive amounts more fuel than i currently do>?

[h4X6]

If a tune is done right you won't use anymore fuel then now if you go with bigger injectors. But it all depends on how big. You can only cut the timing down so much. So get bigger but don't go 1000cc bigger unless you plan on using it down the road.

Sent from my Z30 using Tapatalk

[Skym]

If turn boost levels up, engine would need and use more fuel when on boost. If boost level doesn't excede equivalent to what factory injectors are capable of producing cc wise, probably won't use as much fuel as what engine would with factory injectors. It's up to the tuner how rich they run the engine.

Fuel injector calculator -

http://www.deatschwerks.com/resources/fuel-calculators/fuel-injector-calculator

Fuel pump calculator -

http://www.deatschwerks.com/resources/fuel-calculators/fuel-pump-calculator

[Fred-R]

I got a Denso 305LPH@60psi (14V) with 1000cc inj. According to DW fuel pump calculator, I'd need a 360LPH pump... Can it cause any issues?

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Awesome, @h4X6 that helps me lots actually!

@Skym your answers have always been amazing, never knew those calculators helped so much!

What would be my best choice as far as ECU goes, to be cost worthy if im not racing or trying to get crazy HP?
just to tune the injectors?

[Dragon Humper]

I got a Denso 305LPH@60psi (14V) with 1000cc inj. According to DW fuel pump calculator, I'd need a 360LPH pump... Can it cause any issues?

Only if you are fully using the injectors...and by that I mean 100% DC. Those charts always over estemate to keep you save. So unless you are pushing 800fwhp you are fine with the single pump.

Also depends on how much boost. The more boost it takes to hit a HP target the more work it is for the fuel pump. Hitting 700hp on only 18psi is much easier on the fuel system than needing 30psi to hit the same mark.



Jon.

[Skym]

@Skym your answers have always been amazing, never knew those calculators helped so much!

Thank you for your kind words.

It's a rough guide at best and should always consult a tuner who has used that combo and can comment further on what they have found from their experience.

There's things like intercooler heat soak, intake temp (hot day, cold day, etc) that might change amount of fuel that's needed. Aftermarket ECU's with MAP sensor have multiple maps for hot, cold (IAT / Intake Air Temp sensor), etc.

With injectors you shouldn't excede 80% duty for reliability of injectors when engine is thrashed (from what I understand, prevents the injector from locking open / overheating). Better to be safe than sorry. With road use there's only short burst's, and don't have the potential to lock or overheat, so injectors can be opened more than 90% duty. Most tuners I have known use 80% duty as the safe area.

I got a Denso 305LPH@60psi (14V) with 1000cc inj. According to DW fuel pump calculator, I'd need a 360LPH pump... Can it cause any issues?

Like DragonHumper has already said, only when using injectors at higher to 100% duty cycle.

Could result in not enough fuel through injectors due to low fuel pressure (fuel pump should supply 10-20% more fuel than injectors need to be safe, talk to a tuner who can explain it better than I could).

Fuel pressure needs to be equal with boost pressure (1:1). That's why most FPR's are 1:1 and when vacuum is gradually removed from FPR (when engine is under boost) the fuel pressure rises up to +7.1psi (stock FPR vs stock boost level of 7-8psi) over the 35.5psi it had at idle (off boost).

The fuel pressure is dropped at idle because the vacuum of engine sucks fuel out of injectors, thus the lower fuel pressure helps to prevent engine from flooding with fuel. Higher fuel pressure is needed on boost as the boost pressure in take manifold can stop / make it harder for the fuel to exit injectors (engine runs lean and fails with lower fuel pressure when engine is on boost). That's why you never lower the fuel pressure and use ECU tune (close the injectors more) to take the fuel out.

[h4X6]

ECU tune, for best money and not going for craziness, nistune