leecavturbo

right i'm having a blonde moment surely if the fuel feed pipe from the pump to the rail is the same size , the only way to get more fuel out the end of the pipe in a set amount of time is to increase the pressure ? so in order to have more flow at the same pressure is to have a bigger pump and feed pipe!
me thinks ? what do you ?

GARETH T

yes you are right but if you dont need the increase in flow (higher injector duration) you just wasted alot of time/money!

do you think you have reached the flow limit of your fuel pipework size?

gearboxman

What you must remember is that pumps create flow.
It is the restriction to that flow that creates pressure.
If you allow more fuel out of your injectors than your pump can supply (allowing for the extra margin needed to maintain pressure), then yes you will need a means of flowing more.
That would typically mean a pump with a higher capacity, and quite possibly bigger pipework.

leecavturbo

my theory is , i have a fuel pressure gauge coneected to my fuel rail that i can see/read in the car whilst driving, if i cannot satisfy demand at a given pressure say 3.5bar at full load/high rpm then that pressure reading should go down? if i'm not keeping up with demand then surely just fitting a higher flowing pump won't resolve it cus of pipe work restrictions? to get more flow out the end of the pipe without increasing pressure is surely to increase pipe diameter along with a pump that can flow what isneeded at the pressure needed!

leecavturbo

anyone

Turbo lag

up

stevieturbo

It depends what is causing the restriction. It could be a pipe with too many bends, or too small diameter. A better pump wil help this situation, but only to a point.

But how much power do you need to fuel ? And how bad are the fuel lines you are using ?

I know a few Subaru guys are pushing 500bhp on the factory 8mmOD steel line and a single Walbro pump. Maybe not ideal, and perhaps there are restrictions, but it is still working.