[hardparker]

I ran into some issues with boost control on my PS2 X3, in part which I was pretty sure was mechanical. I discovered significant differences between the actuators and flapper arm pivot on the turbofold where the actuator shaft attaches.

Basically, the X3 actuator that I transferred over from my original turbo to the Pure turbo had two problems once installed on the new turbo: 1 - The action wasn't smooth and had some bind to it. 2 - The actuator ended up threaded all the way down the shaft, but still wouldn't calibrate to 5.9 in hg for full closure. It ended up at around 9 in hg to fully close. In theory, it should underboost like that. In actuality it would spike some at WOT and heavily loaded under single gear WOT it would peg the MAP sensor at over 21 psi.

I went to check actuator action on my old core turbo off the car and immediately noticed that the shaft pivot on the wastegate flapper arm was on the INSIDE of the arm. Every other one I've ever seen, including my spare core, has it on the outside. That solved part one of the binding problem. The other part of that issue is the attendant angle of the actuator bracket that mounts it to the compressor. There's more angle on the X3 bracket to hit the INSIDE mounting of the pivot on the arm. The space between inside and out is about and inch, and while the actuator shaft has some wiggle room to accommodate the angle, it wasn't smooth set up as such.

X3 flapper arm pivot - inside mount



Non-X flapper arm pivot - outside mount



As far as the calibration of that actuator not properly calibrating to the requisite 5.9 in hg, I found that the shaft length of the X3 actuator was significantly longer. Which is why it ended up being threaded all the way down the shaft and still needing 9 in mg to seat the flapper. You'll notice the X3 actuator shaft has a jog or chicane in the shaft. For clearance, you'd think, but it doesn't actually come close to touching anything in the area of that jog.

Fortunately, I had purchased a spare core for advance return to Pure. That core had a standard PWG actuator with a shorter, straight shaft that I removed and kept. It transferred over easily and I was able to accurately calibrate it to 5.9 in mg.

So, if you go PS2 on an PWG X3, you'll either need to send your core and specify that you don't want another in exchange. That or source another X3 core with the flapper pivot on the inside to send in. Optionally, pick up a standard short straight shaft PWG actuator to accommodate the outside mount actuator mount core you'll likely get.

X3 actuator on top, non-X on bottom



X3 left, non-X right