I have a Chimeara fuel pump, i've been told its rateed at 2.5 liters/minute at 2.5bar

will that be ok for 310bhp but running 3bar injectors.

Well the 5L Chimera made 340Bhp so all things being equal (and assuming they didn't use a different fuel pump for that model).....

yes

There are equations out there for pump requirements for various BHPs but seeing what the donor car makes is a good indicator (unless your engine has unusually bad efficiency)....

NO. It'll stall the pump and kill it. Those pumps need fuel flowing through them for cooling, and if you stall the pump, it'll overheat.

If the pump is rated for 2.5 bar, winding the fuel pressure reg up to 3 bar will stop the pump.

Are you sure its rated that low? I'd be surprised: my 390SE wedge runs at 3 bar quite happily on an SD1 3500 EFI pump.

Ed.

I don't think the pump is rated to 2.5 bar max pressure, it's just that the flow rate is quoted @2.5bar. Most FI pumps go way way higher than that but flow rate reduces as pressure goes up.

if you buy a 7 bar fuel pressure gauge, rig it all up, and drive the pump directly against the gauge, and see what pressure it takes to stall the pump. This will tell you its ultimate pressure.

Dont do this for long though: it'll knacker the pump if you leave it stalled...

Putting the car on the rollers or similar in-car instrumentation will tell you whether the pump is man enough for the engine. If its not, the AFR will go well lean at high RPM and throttle, i.e. in the higher RPM echelons of a rolling road power run.

HTH

Ed.

[Edited on 9/5/07 by ed_crouch]

Thanks Edd, ill have a look into that.

ps do you work at Sindles farm.

Stuart

Nah. Engineer.