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Originally Posted by sperry
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Originally Posted by murphy
you could try it..but stock ecu's can't compensate for higher flow injectors and you will run richer than you wish to. or you cold just try the pump and see how it goes. The pump will help a little. its also in what goals you have. you could also do the fuel delivery mod. that they use on the 2.5 rs to the #3 cyl. gets enough fuel.
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I thought the stock O2 sensor took care of that. Basically the larger injectors add more fule at a certain duty cycle, so the car runs rich, the O2 sensor sees this and tells the ECU to reduce fueling, so the duty cycle goes down.
Perhaps that's only something that's done with a remap of the ECU. All I know is, I wouldn't bother with a piggy-back AFC when you can reprogram the ECU to do it. The ECUs in Subarus are powerful computers! Use them to your advantage! |
I have a hard time believing that Subaru allowed duty cycles to creep over 90% on a stock turbo, but I'll concede that for the monent. If it is the case, then adding a stronger fuel pump will cause all the injectors to flow more at any given Gamma time. Injector flow is
always based on the fuel pressure at WOT/full boost since turbo cars almost always have rising rate regulators. Hence, raising the fuel pressure essentially increases the size of your injectors. Also, if you were to only add slightly larger injectors, say 650s to replace the stocks, the stock ECU can correct for them. Very large injectors of course require reprogramming. And I would never make a mod of any kind to fueling with reflashing the ECU. Piggybacks like EBCs and SAFCS are no longer the best solution for working with modded engines. There's absolutely nothing you can do with any combination of piggybacks that you can't do with a reflash, and there's a hell of a lot you can't do with piggybacks that you can with a reflash. We're past the days of rejetting carberateurs here- these are highly sophisticated machines, and shortcut methods are not the best approach.