Is your mbc ball and spring or bleed style? You should put some type of restrictor coming off your vacuum line from the turbo to your mbc to your wga. Think about it your resitricting air to the mbc before it gets to the wga. That means less air hitting the flapper and more boost to redline. U dont beleive me hook up your vaccum line to the turbo straight to your stock wga with the PT spring and promise you will not see no more than 10 psi. Cause all the air is hitting the flapper and deverting the exhaust away from the compressor wheel. Also use smaller vacuum lines. I say no more than 7/32 same concept restricting air to the mbc after it gets to the flapper. But still I use 7/32 vaccum lines and a restrictor. But holding more than 18 will be really hard to do since the turbine is so small.
tubro->resistor->mbc->wga
I use this as my restrictor and its barly open. I know its ghetto but it hides under the intake anyways so no one can see it.
But if you notice in the ad for stage one it says it holds more boost to redline because the stock solenoid has a different program and is restricting air to the wga and thats why it gets 15 psi in first gear rather than 10 like the stock pcm.
