Fuel Pump Capacity info

[Scott.T]

Something I stumbled across that may be of use....relating to Newage STi Fuel Pump Capacity

The Sti runs 550cc injectors (some call them 500's others 550's) but they are mapped at 552.
That means they flow approx 552cc per minute
Therefore 552 x 60 = 33120cc = 33.1 litres per hours.
then mulitply this by 4 for 4 cylinders = 132 ltres per hour.
The standard pump has a flow rate of 145lph so you can see it is within spec of the fuel pump.

This is based on the injectors running at full capacity i.e 100% IDC open all of the time.
They are likely to be running about 75-80% IDC (1.4bar, VF35) at the current boost to maintain the correct AFR, therefore only flowing around 105lph

A 20% safety margin (that is, the pump can supply 20% more fuel than is actually required) is often cited to avoid overheating the pump or a momentary lean mixture so the standard pump is still within spec.

Anyone know the Fuel Pump Capcities for all the other models ??

Here's what I have found so far :

2002-2005 WRX fuel pump 130 lph
2006-2007 WRX fuel pump 145 lph
2008-2009 WRX fuel pump 155 lph
2004-2007 STI fuel pump 145 lph
2008-2009 STI fuel pump 175 lph

I'm currently running 100% IDC on 440cc.
This equates to 105lph

[Mortster]

So in theory, the standard pump on a WRX will run 'pinks' and a VF safely?

[Scott.T]

Originally Posted by Mortster

So in theory, the standard pump on a WRX will run 'pinks' and a VF safely?

Depends what boost and turbo you run. This will determine the IDC (Injector Duty cycle) and also what overhead % you want on the pump.

255lph pumps are used alot, a little bit overkill in alot of cases. But it is the most readily available upgraded pump on the market.

[Mortster]

But then again, the pump is the cheapest part of the upgrade, so I suppose it makes sense to change it.

[Jolly Green Monster]

the problem is theory doesn't always match the actual in practice..

take an 03 wrx for example.. that standard pump is now 7years old... worth trusting it for the sake of £75 and 45minutes to change it?

Simon

[Scooby Wez]

My car is 10yrs old and 150k running the standard pump.It has been mapped on the this pump and been running for a year now fine.Found the above good reading.