Walbro 190, is it enough? Options

[natedogg]

A 190 matched to 550's with a 2G MAS, hmm. It would probably work. But a 255 with an AFPR and 550's controlled by a MAFT or SAFC/2g MAS combo would work better, but that gets a litte more expensive. I've never had any personal experience with a 190 beyond the tuning that I have done with Marcus in his car. I've heard that it is supposed to flow more fuel at near stock pressures though. The 255 on the other hand flows even more while raising the fuel pressure beyond stock which is why an afpr is recommended to bring the fuel pressure back down to stock levels and tune the injectors through some kind of fuel control. I guess its a case of doing things the less expensive and easier way, or the more expensive and 'right' way. Bold statement DSM forum, I know.

ncgalant- Your 255 will flow more than a 190 even if its not rewired. It also raises your fuel pressure beyond stock especially when it is rewired. The easiest way to tune with it, especially with your big 720cc injectors, is to bring the fuel pressure back down to stock levels with your afpr (get a fuel pressure guage! ) and let your safc do the tuning with injector duty cycle. One can raise or lower the fuel pressure to get a bit more or less fuel per pulse, but when it starts getting to high or too low the spray pattern can change into something undesirable and less fuel atomization is achieved. This can cause bad gas mileage, stuttering, misfires, bad idle, plug fouling, and worst of all knock.