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Fuel Pressure Regulator Or 740cc Injectors

Turbz RB-25
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Turbz RB-25 Experienced

Turbz RB-25

Posted
Posted

Hi Fellas,

At the moment, I have nismo 555cc injectors. I currently have 311 rwkw but will be putting more boost in the car soon to get around 370 rwkw and I will need a slight fuel upgrade.

My tuner suggest putting a fuel pressure regulator on the car rather than get 740cc injectors, what do you guys thinks?

WHat are the advantages and disadvantages of both?

First difference is price I guess, injectors are $900 where as FPR is $160.

Is there disadvantages associated with running a FPR?

THanks fellas

2LV8ETR Mentor

2LV8ETR

Posted
Posted
My tuner suggest putting a fuel pressure regulator on the car rather than get 740cc injectors, what do you guys thinks?

Is there disadvantages associated with running a FPR?

The NisMo 555cc should be good for between 260-330kw. My belief is that you are running them close to their full potential. Go the 700cc if your budget will allow you to eat.

The only disadvantage with an FPR is that sometimes heat will cause them to crap out. This of course depends on the brand. The Malpassi rising rate FRP's are known for this. Keep it away from your exhaust manifold (The fuel lines are in the intake side) and you should be good.

blind_elk Grand Master

blind_elk

Posted
Posted

You can, generally, fairly safely increase the fuel pressure to the injectors with an adjustable FPR. But keep it sensible.

By increasing the fuel pressure, you get a much better spray pattern, and therefore better atomisation of the fuel in the mixture.

2LV8ETR Mentor

2LV8ETR

Posted
Posted
So are youu saying that with a FPR i wont be able to reach 370 rwkw?

Not with the 555cc's.

But for high power applications FPR's are a must.

While the pump provides fuel flow, the FPR will hold a given amount of pressure at the fuel rail. This is of course limited to the fuel pump used. The fuel pump must be able to supply the amount of fuel required by all the injectors in wide open throttle (WOT) conditions at the maximum boost level anticipated. A 20% safety margin (that is, the pump can supply 20% more fuel than is actually required) is often needed to avoid overheating the pump or a momentary lean mixture (and possible damage to pistons, valves, or rings). If the fuel pump is not up to the task, then the pressure will not be present at the rail, thus limiting the injector efficiency.

As the fuel pressure can impact on the amount of fuel discharged throughout the injector cycle it is vital that this pressure is kept constant and with this aim excess fuel is sent back to the fuel tank through the fuel return circuit located within the regulator.

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