I disconnected the return hose (hose that connects the regulator and the metal line) at the metal line, put an extension hose to reach to a container (used 1 gal oil bottle works great). I jumped the + end of the coil to get the fuel pump running, then time it for 1 minute then shut down the pump. I got about 3.4 qt in the container.
Using (3.4 x 60) / 4, I get the flow number for gallon per hour. Then using this awesome website, I get my liter per hour. http://www.convert-me.com/en/convert...llon_hour.html
My Walbro 255 HP fuel pump, with a 3 bar regulator, a big BOSCH fuel filter, and at 12.5V, flowed 193 lph. I'd imagine when the car is running at 13.5V, the fuel pump will flow a little more. Now, I know what HP my fuel system can support.
Do watch the container carefully, if it pass 2 qt while at the 30second mark, stop there, other wise, it'll over flow. Use this equation (QT x 120) / 4 instead if you use 30second instead of 1 minute.
Do be careful with the flammable gasoline, get it on the hot exhaust manifold and your car will burn down.