Supercharged Vt Boosting Problem?

[SuperVt'00]

Hey all I'm new here.
I've got a Supercharged Vt, and I've got a little bit of a problem. The standard boost is 6psi, my boost gauge read 4-5 psi which is normal. I bought a 12psi pulley kit from Mace Engineering a while ago and decided to put it on since I've got time. All went together nicely, but the end result is what really confuses me!
I took it for a drive, put my foot down a bit for it to change back, boost gauge reads 7psi, put it down a bit more just comes on 8psi. There's something wrong here, because I can't feel any difference in power. I should be getting an extra 15-20kw with extractors, cold air intake, high flow cats, exhaust, etc.
I took a video of what it was with stock boost and compared the two, absolutely no change except for a very slight bit. I just don't understand why, I've done the same thing to a vy and no problem reads 10-11psi. If you's could help me with this I'd be muchly appreciated!

 

[Tree cutter]

Bypass valve actuator would be the first thing to check.

 

[Immortality]

Yep, I too would suggest checking the bypass valve is operating correctly.

12psi pulley on a standard tune probably won't be to happy either.

 

[Decicrate]

You will not always get the PSI that the pulley is rated to. I would do a boost bypass solenoid deletion and then see what figure that you end up with.

You really should not be running more that a "10PSI" pulley as the ECU will start to pull timing and you will actually go slower.

To delete to boost bypass solenoid is a quick 5 minute job.

If you look on the back of the passenger side head you will see a little black box with 2 vacuum lines and a electrical connector.
Don't touch the electrical connector.

You need to follow the two vac lines.
One will go to the vacuum/boost tree on the side of the blower, the other will go to the boost bypass actuator.
Both these lines need to be disconnected.
The port on the vacuum/boost tree needs to be blocked off.
The port on the boost bypass actuator needs to be left open.

Doing this simple modification will stop the ECU from bleeding away any boost.
The Boost bypass actuator will still work as it should.

Once done go for a drive and see if there is a difference.