While not exactly TPI related, this seems to be the proper forum. I am in the process of gathering parts for a custom MPFI setup on a single plane intake. My question is in regards to the fuel rail/VAFPR setup. Is there any difference or which is better and why? Using a single port return style regulator with the output port connected to one rail and the return line and the fuel feed line connected to the other rail with a crossover in between or using a tripple port return style regulator connected to the feed and return lines and one port connected to each rail with a crossover in between. In looking at other popular conversion setups, it seems pretty evenly split as to which setup they use. I am interested in the technical details so please don't just give an opinion without an explanation. TIA

 

It's a simply hydraulic system. Just provide regulated pressure to both rails, and allow a return to the tank from the regulator. However you accomplish that and with whatever hardware you choose is mostly irrelevant. The second fuel rail needs only a single line to provide regulated pressure. A second "crossover" is unnecessary, but also will do no harm.

 

So neither setup has advantages over the other. Is that what you are saying?