by dpuckett » Wed Oct 17, 2007 3:15 pm
"At the injector's limit" means that while you can turn up the pump, there is little to no more dependable power to be attained with (stock) VE internals- pressures build up too high for long term reliability. Basically, you have reached the proverbial wall, and need either internal pump mods, or bigger sticks to get more power. I think reliability is a bigger concern for us, as the pump is lubed exclusively by fuel, and many of us dont have the cash to pay for trial and error, or have the pressure to feed huge injectors.
Pop pressure determines line/ pump pressure to a point. When you only have 6 holes at .009" (stock), the pressure will spike higher; because there is so little fuel coming out (relatively); compared to, say, a 6x.012 (77% more than stock, by area of holes- it could be a higher percentage, as I have only had beginning physics). There is nowhere for the built up pressure to go, except back into the pump. Lower pop pressures will relieve stress on the pump, but so will larger/ more holes. Simplified, more area for the fuel to go. Both methods can increase fuel getting into the cylinders.
So, yes, begle, bigger injectors can make for less pump pressure. But, you also have to mind that you dont open things up too much and have fuel dribbling in. The VE is much more limited in pressure and volume than the P7100, but there are ways being worked around that as we type.
Daniel
His- 93 W250 club cab LE, auto to Getrag conversion, piston lift pump, 3.54 LSD. 400k+
Hers- 04 QC 4x4. Built auto, Triple Dog, Air Dog. Funny Round truck that aint so quiet.