ok let me get this straight. a throttle body is what regulates the amount of air going into the engine right? when you press the gas pedal you are letting more air in thereby causing the computer to put more fuel in. also what is a plenum?

 

The throttlebody is basically a round cylinder that has a blade in it which opens or closes to allow more air into it.

The plenum is where the air from the TB goes into before going into the intake manifold.

E.

 

You guys are both right.

The plenum is basically a 90 degree elbow that connects the throttle body to the intake manifold. The air passes the throttle body horizontally, the plenum turns it 90 degrees to blow vertically (down) into the intake manifold. The computer does the math to mix the correct amount of fuel with the air you are supplying. You could almost replace the plenum with a nice large piece of PVC pipe, but there's a little bit to be said about the cosmetics of such a modification.

You gain a little bit of extra horsepower by installing larger and smoother TB&Ps because you can get more air into the engine through a larger and smoother path than the stock parts. The new TB might operate a little smoother and therefore give you quicker throttle response.

These changes will not make a huge difference but for a few bucks you get a few extra horses and maybe a nicer look. Make SURE you have switched from the paper air filter to a K&N type so you can get the air to the TB&P.

 

thx for the info