For what kind of vehicle, your bike? I know on a Mustang you can add 8-11 HP (depending on the model). Im sure you could probably find the DYNO results somewhere.
ive read before that headers don't always add horses, and in some cases adds an average of 0-6 horses. I am just wondering if anyone has some results somewhere or know off the top of their heads.
I know for Mustang enthusiasts Hooker Headers are a popular choice, especially on older models. I know Ive seen Mustang mags where they were Dyno'd and added a solid 10 Horses. Like I said, it really depends on the model.
Here in Toronto Canada, we add spoilers on our rice rockets to add horsepower. You should check that out. Go the manufacturer websites. They usually have dynos done showing performance. Pick out the top brands that you are considering, and check them out. If not, google the make and model of the header and your vehicle type. There are so many project cars out there, you will more than likely find a similar set up to yours.
