Hey Mario. Do you have before and after dynos on the installation of your custom 3inch exhaust? If you don't have those then some before and after 1/4mile slips would be intersting.

 

No I dont. According to research I have done on a Turbo engine the less back pressure is better. I am already running a smooth 12psi engine, quite wild!!. On the naturally aspirated it doesnt work this way, you need your headers and cat to help you pulling remaining gases, so bigger is not better. On turbo applications not the case.