next week im getting my exhaust done(3" single w/headers,no cat,hooker aerochamber muffler) and Im putting in 2 9" k&N open elements in place of my cold air cover with filters.
The engine is otherwise stock with no more air pipes. How much of a gain do you think I might be in for?

 

Not sure of an exact HP number, however I guarantee you'll notice a big difference. The exhaust on these cars is very restictive. When I had mine done it didn't even feel like the same car!

 

isnt the full exhaust without the cat worth like 2 or 3 tenths of the 1/4?And headers like another 2 or 3 tenths?