First... unless you're stock, or the other car had identical mods... it means nothing at all.
Second... you are the ONLY person, that I'm aware of, that says it works. I also have the complete schematics of the vacuum lines that run the supercharger, along with a few other odds and ends. If you look at the same info that I have, and you're smart, you'll come to the same conclusion.
The mod that Clownhair has posted IS the mod that you're talking about. Not the 'pull the vacuum line and stick a golf tee in it' mod. You've played with the car, there's not ONE OUNCE OF BOOST that makes it past that line to the actual blower. Give it a shot, hook up your boost gauge to the line past the solenoid. You'll see that it's an open and close solenoid. You will read 0 on the gauge untill you let off the gas, then it will plunge into vacuum. Thats to give you part throttle driveability.
The actual limiter works differently than this particular mod will allow to be effective...
Go ahead and explain to me how that solenoid controls the boost. You'll quickly find that there's NO way for it to. All that thing does is allow the vacuum from the manifold suck open the bypass when you're crusing. If it allowed boost through, the vaccuum canister would pop....