Todd, do you still have the link to this actuator?
 
Thanks,

Dave Leonard

Hi Dave;
        I'm not sure which link you are looking for? If you are referring to the e-boost controller that I just ordered, then it can be found at www.turbosmart.com.au , however it is not an actuator, but rather a controlled bleed solenoid that is installed in the sensing line to the actuator (you probably already know this),

        If you are referring to the simple absolute pressure actuator that I desired then it is a mythical creature that I've never found, but it is so simple that I'm surprised I can't find one. I've thought about building one, but without a vacuum chamber to assemble and weld it, it would be very difficult. My idea would be to use an actuator with the top of the diaphragm containing a perfect (or close to) vacuum and a 16 pound spring. The bottom of the diaphragm would be connected to the MAP sensing line. Then the actuator would always try to balance the MAP against the spring pressure only regardless of atmospheric pressure. This will cause the actuator to always try to maintain 32.5" MAP (during wide open throttle), regardless of altitude... very simple and effective. Unfortunately I can't find one. Auto applications don't desire this feature and aircraft turbos are so ridiculously priced that it's not even worth looking at. Building one would seem simple enough, however as I only have a vacuum pump I would need to install a valve on the vacuum side of the diaphragm to apply the vacuum, then close the valve, disconnect the pump and install a plug in the valve. Eventually the valve stem packing would leak, so full vacuum would have to be reapplied periodically. The ability to assemble this inside a vacuum chamber would eliminate this issue. The MAP side of the diaphragm  would also require a packing box on the shaft seal. These issues could easily be overcome at a production scale, but for a one off it would be a challenge indeed.

        So unless I can find a source for an off-the-shelf actuator, I pinning my hopes on the E-Boost.

(Probably much more than you wanted to know :-)

S. Todd Bartrim (still waiting for the kid)
Turbo 13B
RX-9endurance
C-FSTB
http://www3.telus.net/haywire/RV-9/C-FSTB.htm

        "Imagination is more important than knowledge"
                                        -Albert Einstein