Just purchased one for mine, yet not installed.. Just wanted to see if the proclaimed gains are true and what others have experienced??

 

I just got one too (used). I would also like to know about true gains.

Badzy, can you do me a huge favor and provide me with the measurement of the rear bolts? Mine came without them and I haven't been able to get in contact with IPD, after leaving several messages.

Aslo, I heard about polishing the inside for better and smoother airflow. What do you guys think?

 

A smooth surface is not always optimal for air flow. Go read some fluid dynamics books. In their latest version they have dimpled the inside surface.