I have found than any gains from lifting the floor of the exhaust port is negated by the sharp turn of the pipes as they exit the port. This sharp turn is due to the limited clearance in clevo powered falcons.
XR6T manual ute 14.3@100mph 1/4(wsid)
351xd manual 9.2@76mph 1/8(cid)
MKI 2door Cortina.
Too much power is not quite enough