does this restrict any power as i can only run about 12 psi before the car feels as if its struggling with anything over that or is this pretty much all you can run got big exhaust standard intercooler uprated braided hoses air filter not sure what elae but also got apexi fc commander

 

What model year car?
Best to find out what else you have on the car.
If you have the commander then you have a Power FC instead of your standard ecu so that may need looking at by a mapper.