ok heres the story... this past spring my friend and i performed a swap from a S4 to a S5, but not just the block the whole shibang so currently im running on the S5 ECU, we've fix all the minor problems and what not but there is still one issue that we have yet to deal with... THE BOOST!~ at first the car wasnt boosting because the waste gate was stuck open, we fixed that... it now boost's but not as hard as my previous S4, which leads me to disapointment, with my S4 i could build boost up to 10 psi, and my BOV was extreamly loud like a bus even loader! now im only boosting 5psi and my BOV sounds like a silent but deadly fart and most embarrassing of all i lost to a friends GSR . my friend who did the swap for me is a very busy bee, and doesnt have time to find the problem. this is a plea for help...

 

S5 tII has stock electronic boost controller to reach the stock 7.5psi, if u remove it u get the stock s4 boost of 5.5psi (cos the turbos have the same turbines)