Fuel pump - trying to clear up my confusion

[streetbikestunta420]

What's up peopleSo I wanna raise the boost on my car so oviously imma need injectors and fuel pump,ect. I was looking at the walbro 255 ltr/Hr pump and was wondering up to what power would t b good for? Would it b capleable of handleing about 400-450 hp to the wheels at about 15 lbs boost or should I get one wit more flow? Also I waS searhing but all I found were people wit problems and that didn't really answer my question but what's this about the pumps not getting full voltage w/o a relay or something? I read but diffrent post confused me, what would b the best way to wire it? Please don't flame if ur not gonna help at least post a link to lead me to the right path .

[supreamS14]

I think a walbro will flow 550whp. I would think wiring in a external relay would help reach that peak without problems. I know for 600+whp you need more than a walbro 255lph.