I tested this during tune up today
try to hold 16SPL
start tt 1.25
end tt 1.05
most of the outbound lengths were early to middle 15SPL
most of the inbound lengths were 16SPL on the nose, the last couple were just inside the beep, so I decided it was time to stop.
2 beep push off, 2 beep turn. Rest interval long enough to build a gap in the lane 30-60s