I was always on the understanding that to get a rough injector size when changing pressure, you used the following formula...
SQ ROOT (new pressure / old pressure) * old pressure = new flow rating
i.e. SQ ROOT (4/3) * 259 = 299 cc
In saying that though, the only way to know for sure is to actually take measurements.
When trying to push more than 400 WHP, we maxed both 555cc injectors and the Walbro 255HP pump.
Base fuel pressure was set at 4 BAR, and while trying to push 1.5 BAR (22 psi) boost pressure (therefore 5.5 BAR fuel pressure), the injectors were at 90% and the fuel pump itself couldn't provide enough fuel.
I had to upgrade to modified 740's and a Walbro 255 HP / Bosch -044 combo!
SQ ROOT (new pressure / old pressure) * old pressure = new flow rating
i.e. SQ ROOT (4/3) * 259 = 299 cc
In saying that though, the only way to know for sure is to actually take measurements.
When trying to push more than 400 WHP, we maxed both 555cc injectors and the Walbro 255HP pump.
Base fuel pressure was set at 4 BAR, and while trying to push 1.5 BAR (22 psi) boost pressure (therefore 5.5 BAR fuel pressure), the injectors were at 90% and the fuel pump itself couldn't provide enough fuel.
I had to upgrade to modified 740's and a Walbro 255 HP / Bosch -044 combo!
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