I agree with everyone don't boost more than 22psi on stock ecu and it will taper not matter what

 

^^^Umm okay??? The ecu has no control on how much the boost will taper with a mbc. The reason it tapers is because the turbos runs out of efficiency at higher boost and cannot hold it past 6000 rpm. The only way the stock ecu controls boost is through the stock bcs and it still will taper....stock turbo will only flow so much plain and simple.