The device you are installing is simply a modified version of a pressure relief valve that is available at Graingers. It does not allow your wastegate to see any pressure up until the relief valve opens; thus it limits ‘wastegate creep’ and allows the boost to increase a bit more rapidly.

If you use this relief valve in conjunction with a pressure regulator, when plumbed properly, it can make a real difference by not only limiting wastegate creep, but also allowing you to control the boost pressure without having to mess with the wastegate spring.

Now for the downside… I just got through changing all the fluids & checking everything over before I embark on my long haul kamikaze run. I checked my boost pressure, and found that I was peaking at almost 18 PSI, and spiking to 20 when it upshifts!!! (I thought she was running a little too good for a diesel.) I am changing the pressure regulator tomorrow. It either failed, or became plugged. Lesson learned: If you have anything other than a simple open line running between your manifold & the wastegate, keep your eyes on it. If the line becomes plugged, you’re going to see some serious pressure!

Glenn