I've heard that hedmen headers, or even hedders in generaly don't give you any HP, but i've heard otherwise. I jsut installed hedmen Hedders with Y-pipe. Am i expected to gain a bit of HP? even if it's 1 or 2 ?!?!?!?!?!?

(it's on a 5.0L - 305)-- if it matters.

So basicly do hedders give you more HP?!!?!?

Headers generally give you better exhaust flow by giving each exhaust port a dedicated tube away from the engine, whereas exhaust manifolds generally converge the middle cylinders exhaust gasses into one port and effectively "log-jamming" the exhaust. Any time you can help the engine "breathe" either on the intake end or the exhaust end, you will create horsepower. You are essentially helping the engine be more efficient and help it do its job easier.

You will generally see anywhere from 15-40 hp from headers (depending on how restrictive your exhaust system is) and similar increases in torque (low rpm or higher rpm depending on long tube or shorty headers).

Steve

thanks man

I got 20hp from adding my Edelbrock headers and a high flow cat.

Look at any stock exhaust manifold, and then look at a header... The difference is striking. To claim no power increase from a set of headers means either the current headers/exhaust manifolds on the car flowed more than enough.....or whoever said it has a serious problem with their butt-dyno. Fox-body Mustang 5.0's came with "headers" stock. That is, they didnt have the log style manifolds, but each cylinder DID have its own dedicated tube. However aftermarket headers STILL improved exhaust flow and added power through larger tubes, smoother bends, and equal-length tubes versus the factory un-equal.

There are a few cars that would not fully benefit from headers. Those are cars that need backpressure to help pull the exhaust out of the cylinders. You would still get more hp and tq than stock, though. Basically, though, if a company makes headers for your car, and you can afford them, get them because you will get more power.

cool. thanks

you are confusing scavenging and velocity with backpressure. Think about what backpressure is. There is no way it can do good.

Smaller diameter, longer tubes = more torque

Large diameter, shorter tubes = More HP

Thats a pretty general description, but is more-or-less true.

On our cars, headers are the first thing that should be installed IMO. Our exhaust systems need all the help they can get.