I just got what is supposed to be a S5 JSPEC turbo engine from an attempted TII conversion. Someone did the emission/rats nest delete so I got no solenoids with it. From what I gather most of the solenoids are the same part# as the n/a ones, except the Boost Control Solenoid. I read that if running more than 8psi it was useless. So my question is since I plan to run 10psi of boost do I even need the stock boost control solenoid? There's one on Ebay and I needed to know if I need it? Also I plan to run a standalone if that makes a difference on whether I need it or not. Thanks.

 

Not needed as long as you use a boost controller.
Back in 2002 on our '89TII when I installed the G-Force ecu it actually destroyed the boost solenoid as it was working constantly trying to keep the boost up, so I disconnected it and installed a Hallman remote to keep it @ 13lbs.

 

Thanks.

 

Should run the stock boost solenoid unless you have a aftermarket boost controller if planning on stock boost with stock ecu. Otherwise grab an electronic boost controller and control t with your standalone.