I can answer this one since it was my car being tested..
When my car was dyno'd previously to having the box installed it already had the BMC filter which was good for a few extra horses, so taking that out and adding this intake made up the extra difference.
I hope that clears things up for you.
Originally Posted by Eugene-TAIWAN
Its a very nice looking product.
But I don't understand for the people who have a HFC you will only get 5BHP from this system!
Then thats just like putting in a drop in filter. Right?