We use TFT's on 1.75" w 100 psi settings. We send 200 p.s.i. to them. This should, in theory, give you 200 gpm provided you don't have kinks and the TFT is in proper working order. Realistically because of friction loss, kinks, (ever seen a line with no kinks at all?) but 175 to 180 is probably more like it. Our TFT's are well maintained, but those kinks are, well, kinks. We kick 'em out as best we can. We use a smooth bore and 2" on hi rise jobs.