Originally Posted by shu873
Add it now. Not only will it not hurt anything, it's better fuel delivery then the stock HFCM. Even stock injectors can cause you to drop fuel pressure with a hot tune.
Either my TSD SPD must not be that hot of a tune or my stock HFCM is on steroids or my RR kit actually supplies more fuel to the heads because I have my fuel pressure set at ~60psi and it drops maybe 2psi on a WOT run.
An AD2 is probably good for removing air in the fuel and having the ability to deliver a larger amount of fuel than the stock HFCM, but IMO the stock delivery system is where your hugest restriction is and a RR kit is needed regardless of what type of fuel pump you run. While I dont have one yet, I also believe a sump is a very much needed item as well to remove A LOT of strain on the fuel pump from being required to suck/draw fuel up from the tank and to the pump. With a sump installed, hydrostatic pressure from the column of fuel in a full tank forces the fuel to the pump so it doesnt have to pull it itself. It is only when the tank getst near empty (i.e. the level in the tank gets below where the fuel pump is) that the fuel pump has to start pulling fuel again. So for probably 3/4 of the time, the fuel pump will see an easier lifestyle and in theory should last longer. JMOs.