Fuel pressure ????

[Meatball]

Couple of questions,
Whats would normal or average fuel pressure be running standard ecu and injectors on a 450/500?
and Whats the max fuel pressure the standard injectors will take?

Just curious

[Meatball]

[clive f]

pressure in the rail, or injector rate?

[Meatball]

clive f said:

pressure in the rail, or injector rate?

Both
Clive did you buy one of those AFM`s
Ben

[griffter]

pretty sure it's 36 psi. this is determined by the fuel pressure regulator - the pump works overtime and any excess fuel returns to the tank.

[Meatball]

griffter said:

pretty sure it's 36 psi. this is determined by the fuel pressure regulator - the pump works overtime and any excess fuel returns to the tank.

Anyone know the max psi the standard injectors will take.
42 - 43 psi at a push????

[clive f]

fuel regulator set to 40 psi, not sure on injectors though.
didn`t get one of the afm`s, have a cunning plan

[rev-erend]

Don't know the max pressure for the injectors but the older the injector the worse the leakage is likely to be.

So if your injectors are new then I'd say 50psi would be OK if they are near the max flow for their size !

But another strange thing .. as you increase the fuel pressure the pump flow rate drops slightly - so if your engine needs nearly all the fuel the pump can supply then there is a very real change and danger of running lean when under full load (speed)..

[blitzracing]

Only if the ECU has been remapped to make use of the extra pressure, and the injector timing reduced. Otherwise the pressure would simply drop to its nominal 37 psi, and this assuming the standard pump and fuel lines are at 100% capicity at this point, which of course they shouldnt be. I think the TVR setup is good for 300 BHP before fuel supply becomes an issue???

[GreenV8S]

The normal pressure is either 2.5 bar or 2.6 bar depending who you ask, I'm in the 2.5 bar camp. If you have the original disc style injectors then I understand that raising the fuel pressure beyond a fairly low limit becomes counter-productive because of the effect on the opening times. I don't remember what the maximum useful pressure is, I suspect it's above the standard pressure but I can't say how far above. There are uprated injectors available which have a higher flow rate and also a better spray pattern, if you're considering upgrades to this side of things. They aren't cheap though, and you will need a remap afterwards.

[Meatball]

Thanks chaps