Here is some figures I got from my racepak as far as when a poppet opens during a run in my system . This is a lencodrive leaving at 4k rpms . My loop is set at 40 lbs. and opens .059 into the run , I don't use a typical high speed on the back of my K valve that most would set around 60 lbs but if I did it would open at .144 (6300 rpms) and if it was set at 80 lbs. it would open at .193 (6600 rpms) into the run . Of course the opening times would vary depending on such things as pump size , orrifice area and so on , but it all opens pretty quick .