The Aeroflow Performance diesel specific manual boost controller is a dedicated unit for diesel turbocharged engines running variable vane turbocharges. It provides accurate boost control from the turn of a knob. This manual boost controller allows the 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 bring on boost earlier or hold it longer. When the factory boost curve is erratic this can lead to engine or turbocharger premature failure.