I'm with you, I understand the association of boost to FP with our systems but that calculation doesn't seem right.
I was under the impression that our fuel regulators being vacuum based, worked as such:
On positive vacuum, no demand, fuel flow is restricted by the regulator to a specific point, therefore 40 psi to the distribution rail at Idle.
On the cusp of pos. vacuum / neg. vacuum (boost) the regulator opens more, therefore 45 psi at even pedal / cruise.
With neg. vacuum (boost) the regulator opens more to meet the demand called upon it, dictated by that amount of neg. vacuum, therefore more neg. vacuum/boost more fuel for the system, and with my boost level of 19.5 or so that gave me 66 psi. at the rail.
The whole reason I attached my gauge to the fuel rail was to read these changes and see the demand of the engine on the system, if I had attached the gauge pre-regulator, I would have only been able to read the fuel pump psi, which is a constant reading somewhere in the 60's.
Fuel injectors are rated on the pressure over the manifold.
So the pressure that the injectors sees is the fuel rail pressure minus the manifold pressure.
if i have 66psi rail pressure and 15psi of boost the net differential that the injectors see is 51psi because i have to overcome the pressure in the manifold to spray the fuel.
My understanding is that the mini fuel system has a max pressure of 64-66psi at wot, as BlwnAway saw, so any boost over 14-16psi will also start to see an effective drop in fuel pressure.
The reference for the fuel pressure is still vacuum based but the actual pressure the injectors see is based on a combination of fuel pressure and manifold pressure.
You can get JCW injectors for $80/apiece online (13-53-7-574-132 link), so why spend time adapting these other injectors and convincing people they work just as good as JCW injectors? Even if you're saving a fair amount of cost, the potential sales volume is small.
