Originally Posted by intenseblu
its a dead head system ... no return lines. Kleeman claims the pump is good to double the stock standard Xf's rating (400 ft/lb) so the srt pump is not straining ...
i suggest against a rising rate fuel pressure regulator as volume goes down with increased pressure ... so you are fixing the problem of the injectors running out of pulsewidth and introducing a new one of lower the volume the fuel pump can dish out...
i also suggest against larger injectors cause you will be taking drivability away from the car as factory cold start settings and the like will not be supply the same flow of fuel at a particular pulsewidth as it thinks it is ... remapping the ECU for the new injectors is a wasteful pursuit at best due to the money involved...
my suggestion ? auxillary injector ... a extra 90 lb injector and holder can be placed at after the supercharger and before the throttle body ... auxillary injector driver (your choice, emanage, megasquirt, whatever) can be programmed to spray at MAP values beyond the stock systems capabilities ... the schrader valve on the fuel rails can be utilized as a nice neat 4AN fuel port for the injector. its clean, its reliable, its cheap ...
Awesome info about the pump, that saves me a lot of headache.
The problem is, I've already had the ECU mapped once for the 25% overdrive pulley, and it's still not enough fuel. AND on my Apexi I turned the correction all the way up and the fuel is just not there. That's why I'm going for larger injectors. I'm giving the ECU one more chance, and I'm waiting on it's return from powerchipgroup right now. This will be the third attempt. I sent AFR printouts so they can tune around it, but if they CAN'T then larger injectors would be the way to go, and I won't increase them enough to take away driveability. And I have a plan around remapping the ECU around the injectors. I plan on changing to a 2 bar MAP sensor then using my Apexi to set what ratio the injectors are to the MAP voltage. If I keep the ratio linear to the factory settings then the ECU will not need to be remapped, and any small corrections that may not be accounted for I can correct with the Apexi.
I have thought about the secondary injector idea, and even where I'd put it. If I went that route I'd tap into each of the intake manifolds, one on each side. And then I'd simply use the same kind of progressive controller my methanol injection uses. I can set a min and max MAP pressure that it kicks on at and ramps up to until it hits max duty cycle.
But since I can get larger injectors for right around $500, I think I'd rather do that than try to band-aid fix it.