Yup...BUT.
My box in an external, aero ported, box. I have 2 ports that I swap back and forth. A 6 inch, and an 8 inch.
It takes 2200 - 2300 watts to do a 147.8 with the 6 inch port....but 147.8 is all it will do with the 6 inch port. I can throw 3k to it, and all it does is a 47.9 with that port.
With the 8 inch port, it takes right at 2700 watts to do 147.8. However it keeps climbing with more power, with the 8 inch.
8 inch port is used for the outlaw class I run in, 6 inch for the clamped power sealed class I run in.