ive always wondered this.. how fast is air really going when its coming into the engine? anyway to figure it out? i obviously know it's different speeds depending on revs and throttle, but im just curious like what the average and range of it are

 

Damn Good question. What IS the actually velocity? (of a laten swallow)

 

http://auto.howstuffworks.com/question517.htm

Here is an explanation on this if anyone is interested. Talks about the pressure waves and importance of a tuned intake. Hence what we do here at AEM with our V2, Cold Air Intakes and Short Ram Intakes.

AN INTAKE IS NOT JUST AN INTAKE

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rtype16 &raquo;</TD></TR><TR><TD CLASS="quote">http://auto.howstuffworks.com/question517.htm

Here is an explanation on this if anyone is interested. Talks about the pressure waves and importance of a tuned intake. Hence what we do here at AEM with our V2, Cold Air Intakes and Short Ram Intakes.

AN INTAKE IS NOT JUST AN INTAKE</TD></TR></TABLE>

Ahh damn so quick to answer without actually reading...

We want to know the ACTUAL velocity inside the intake tube going towards out engine. Can you answer that mister AEM?

 

Air velocity isn't really measured, it's inferred. AFM (air flow meter) is the closest thing to actually measuring it, but in reality, its more like an air temp sensor. Honda uses primarily MAP and not AFM as far as I know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shaundrake &raquo;</TD></TR><TR><TD CLASS="quote">Air velocity isn't really measured, it's inferred. AFM (air flow meter) is the closest thing to actually measuring it, but in reality, its more like an air temp sensor. Honda uses primarily MAP and not AFM as far as I know.</TD></TR></TABLE>

uh, did you even read my original post? i asked what the actual velocity is, like in numbers, how many feet per second or miles per hour, i didn't ask anything about MAP sensors... i know it's not really measured, me and some friends were just really curious about how fast the air is actually moving.... does ANYONE know?

 

Okay okay okay sorry I was just trying to help out the first time without getting really involved and I haven't kept up with this thread so i din't know til i checked today, but now you have pushed my buttons so I will have to think a little. Just a little though. And yes I can answer that.

Okay lets take a 1.8L(109.8427 cubic inches) motor at 8000RPM the maximum flow 100% efficiency is 255CFM (Cubic feet per minute). Now lets take a 3" diameter pipe. Which is usually .065" wall so it is 2.87" now lets take the area of this which is (damn don't have symbols so bare with me) pie(r)2 = 6.469246132 (square inches). Okay now with the formula of velocity(LFM) = Volume(CFM) / area (ft2) we come up with 39.41726668 (LFM) which is 59.032 MPH.

Does that answer your question.

Another little fact for you you may find interesting. Okay lets take the same motor same RPM. At the valves since there are two of them. Which is a 28mm Valve and a 5.45mm Shaft. This computes to 1.102362205" on the valve and .2145669291 on the shaft. Find the areas of these minus the shaft area is 1.836517675. Through the valves the air is travels at 227.209MPH

 

nice work bro..so 50mph through the intake and 200mph at the valve..is that all motor?...sounds pretty fast

 

Yes that is all motor. This is taken at a specific cross section of the pipe.