boost won't increase.

[dannys35]

Ok. here is the problem wanted to turn up the boost on my car it tops out at 12 PSI but the boost controller is all the way open am I doing this wrong should I be closing it.On one side it has a plus sign and tells you what way to turn. On the other it has a minus sign and tells you what way to turn. I turned in the direction of the plus sign and am still only hitting 12 PSI the turbo is a t-61 and I know it should be hitting more than 12 PSI any thoughts or suggestions are appreciated is it just that the car needs to be tuned.I know that it has never been tuned and it is running off the factory ECU should I upgrade that as well.Thanks!!