Just because we haven't had this round of arguement lately. I was thinking, most of the informed guys agree that with map a large or cold air intake is non beneficial on the basis that the sensor will not measure the air coming in. The map sensor measures manifold pressure to monitor the incoming air. The more air the lower manifold vacuum. I assume that this reads down to zero. If this is true you would actually need positive pressure to defeat the sensor. The amount of air coming in is restricted by the throttle body. You can run at wide open throttle and still have vacuum .To create positive pressure usually requires a turbo or supercharger. So if you have no air filter or tube you should still be within limits. Even a small forced air from a cold air kit shouldn't be able to make positive manifold pressure. If this is correct there should be some gains at cruising speed from a well designed cold air system. That doesn't include cutting up your filter box to let hit engine air in by the way. Any thoughts?

 

Much like a freer flowing exhaust lets the air out faster, a freer flowing intake lets the air in faster. You throw off the fuel curve.

 

Not Sure I can consider myself well informed but I happen to have a Cai on my map equipped 5.0 I notice better throttle response improved mileage and I reach cruising speeds with less pedal now.

 

You have a point. I think what we need is to find a physics formula. Can velocity and mass increase without effecting pressure/vacuum? I think ill chat up my physics professor at school.

 

according to bernoulli's equation and basic fluid dynamics, velocity is inversely proportional to pressure.. therefore, an increase in velocity will cause a decrease in pressure.. and vice versa of course.

 

Wait that is backwards. In exhaust a larger diameter pipe makes for a slower flow rate.

 

It leaves at a faster rate because of less restriction. Take a deep breath and blow it out through a straw and see how long it takes to empty your lungs. Then do it like you normally would and see how much of a difference there is.

 

You are confusing flow rate with velocity. Velocity is the speed of the air stream. Flow is how much comes out all at once. Blow on a pinwheel with your mouth open it won't move. With a small orifice like a nozzle it will spin.

 

But do you want it to come out with a higher velocity, or more at once?

 

Either way, the flow and velocity have increased with a less restrictive intake.