I was having serious problems with my AVC-R boost controller recently, and it got to the point that I was going to go back to the Power FC's built-in boost controller, especially after I heard another user blew his motor using the AVC-R/PFC combo. Well, I did manage to re-install the PFC/stock system but unfortunately, I managed to fry a stock solenoid as I would get wastegate boost on the first, full boost on the second. Inadvertently, I'd left the two stock solenoids connected to the factory electrical connectors and one must have burned out. For reference, these are the two solenoids that sit right behind the vacuum chamber.

So, frustrated, I reinstalled the AVC-R. This time, however, I made a few changes. The most important item I changed was to mount the AVC-R solenoid MUCH closer than I had previously...I made the hoses as short as I possibly could while keeping the solenoid out of the extremely hot areas of the engine bay (as if there were any cool ones!). Previously, it had been mounted by the ABS unit at the rear of the engine compartment. I moved it up to the front fender well location, and managed to shorten the vacuum hoses by over a foot.

Initial impressions is that it's MUCH better than before. I'm still getting some boost spiking, not as bad as before however. I did notice that this boost spike, if you were to just sit there and watch the boost build up, isn't visible at all on the gauge, ie. you can't see it as boost builds and registers on the main display. It does, however, register on the peak hold, leaving me to believe that the solenoid reacts so quickly, the gauge doesn't have time to register it. It's now just a matter of dialing in the duty cycles for which I'll be using a video camera to monitor boost/engine revs. It's the safest way as you can go back and play it over and over without taking your eye off the road when making tuning runs. I've been using the self-learn feature as well. For those with the main cat in place, and/or fewer mods, it shouldn't be much of a problem to tune it. As is, my turbos/wastegate is stock, hence the additionally difficult tuning.