The Aeroflow Performance diesel specific manual boost controller is a dedicated unitfor diesel turbocharged engines running variable vane turbocharges. It provides accurate boost control from the turn of a knob. This manual boost controller allowsthe user to adjust the boost control and spool rate, therefore for increasing engine power, reducing turbo lag and create a linear boost curve. This is great for all types of driving conditions from adjusting boost for towing or changing it if the EGT gets too high and to bringon boost earlier or hold it longer. When the factory boostcurve is erratic this can leadto engine or turbocharger premature failure.