Yeah on the zlets hot water is pumped thru the turbo,but on the leh its cooler water pumped thru,so vx did a pipe kit to convert it to the same as the leh...
Taken off aoc.
Cooling Modification = Redirects the flow of the coolant system so cooler water from the radiator goes to the turbo, rather than hot water from the other end of the radiator. This modification is standard on VXR's, and is listed by Vauxhall as a 'field remedy' for LET's.