what are the best bolt ons for horsepower?
 

I have an 07 fit with a short ram intake and a homemade exhaust. I cut the factory pipe off behind the cat. Welded a 2 1\2 inch pipe together all the way out to the back. Put a performance mazda-speed muffler on the end. Got it from a wrecked rx-8. Sounds great. Thinkin about headers and new intake manifold. Lookin at some cheap headers on e-bay.
Any more suggestions? Any coments on the e-bay headers?

for ebay headers... you get what you pay for.

buy a turbo kit or KW s/c kit if you want more HP..

the smaller the motor, the less effect bolt ons will have.
the best (as in the most result) bolt on's are forced induction, or nitrous.
even if you get an intake, headers, cat delete, exhaust you might only gain 10hp at 5000rpm,
it'd be more satisfying to spend that money on aesthetic changes.

when the pipe is that big, the exhaust is moving so slowly, that it doesnt help to pull air out of the cylinders (scavenge). once the airflow is moving at a certain speed, it creates a low pressure zone behind every exhaust pulse that helps pull the exhaust out of the cylinders. its not the back pressure, but the speed of the air moving through the exhaust. the smaller the pipe, the faster the air is moving at a certain RPM. that is of course until the pipe is small enough to choke it. this is all grossly paraphrased, theres a great thread in the exhaust forum about it.

yah, only way to gain real power on this car is forced induction as posted above.

In all seriousness what are you trying to achieve? The Fit is not a speed machine and won't be without some serous cash dropped into it. If you want power get a car with a V8, the 10 HP that you might gain from bolt-ons will only end up wasting your money when a V6 Buick ends up destroying the Fit. Its sad but true. Just enjoy the fit for what it is which is a fun little car to drive that gets good gas mileage.

I just wanted to see how much hp i could sqeeze out of it without affecting the gas milage. kinda figured it wouldn't be a big increase either way. Might spend the money to make it more show instead of go.

Think "bolt off" mods for horsepower. Rule of thumb is that 8 pounds = 1 hp. Do the math.

x2...I love modifying my cars but when I bought the Fit it was for fuel mileage. I have lowered mine and that will be all that I will do to it. I enjoy driving it like it sits.