dieselcarpenter

So, what is a Valet switch and what is its purpose? ?

rbrettctd

Check the sticky. Its a solenoid that cuts down the boost that the pump sees, thus not pushing the pin so far and cutting the amount of fuel the engine sees, while still getting the same air. Great for daily driving and cutting egts.

wannadiesel

A valet switch controls a solenoid valve in the line from the intake manifold to the AFC housing on the pump. In "valet mode", the valve is closed which prevents boost pressure from reaching the AFC housing. This limits the fueling severely, reducing power and EGT. Some guys use the valet switch as a towing mode, it lets them tow without having to babysit the pyrometer on every hill. It lets you have a fire breathing monster when just cruising around, but with a flip of a switch you have a docile plow horse. My truck makes about 260 RWHP in valet mode. In valet mode max EGT is 1100 degrees, with full fuel it will peg the pyro in 4th.