Increasing fuel pump output?

[JTaylor2005]

Alright guys,

I know a lot of people have problems with the fuel pump running out of flow at certain torque and HP at high revs. Just throwing an idea out really. Would it be possible to put a smaller pulley on the pump. That would make it spin faster so offer more potential fuel?

[Piggy]

No. Lol.

R70 is your first step.

Many mods needer to find limit of that

[JTaylor2005]

I have no plan doing this. Just theoretical. What is the reasons for not being able to do that? The fuel pressure regulator would have to open up more so I suppose.

[toseland]

Because the relationship between flow and pressure is inversely proportional. At the extremes you can have either high pressure or high flow.

For tuning these effectively you need a bigger pump as that is capable physically of moving more fuel per stroke. Meaning you can have a higher flow for higher pressures

[Poodle]

Yes that would probably work to an extent, in theory, however you'd be running the pump outside of it's efficiency range and probably not gain a lot overall. Without trying it out you won't know, as per usual. As Toseland explains you'd be sacrificing pressure for flow, fine if you're putting massive injectors on and don't mind losing efficiency, but then you'll need a bigger pump to make the most of the injectors anyway, so...

[Ruan]

Yeah you could, but there's better, larger pumps you can fit anyhu.

Also heat would be a major factor running the pump faster, have a look at what changes with later generation Commonrail pumps as to what issues are trying to be solved.

[JTaylor2005]

I suppose all that would happen is that you would have more potential flow. The pressure would still be the same as it would still be controlled by the regulator but then I suppose that could also cause an issue as it might not be able to release enough through during low load high RPM's which could cause over pressuring of the fuel.

[Ruan]

Fuel pressure is controlled in a control loop in the steady state, so generally for not massive increases in flow, it'll be corrected for well enough. However yes, you may get more fuel pressure spikes than you would otherwise anticipate under fast transient conditions due to the way the control loop works.