Originally Posted by Franc Rauscher
If you put a 3.0" elbow pipe out the window and pipe in about 2 feet of 3.0" PVC tubing you get air to flow thru the pipe. Agreed?
If you cap off the end with a smaller hole in the cap, you will get air to flow thru the hole. Right?
The only reason air would pass thru that hole is because it has a higher pressure than the air in the cabin. The assumpton can be made that the air in the tubing is under pressure. Otherwise the air in the tubing has no reason to pass thru the hole.
It can also be assumed the continuios the ram effect will maintain that increased pressure.
So long as the volume of air collected is greater than the volume of air consumed, the intake should have positive pressure. This is a function of the size of the collector orfice.
So now you have more air coming into the TB with increased pressure. Is that not how mechanical compression systems work?
roadster with a stick
I'm almost positive that a boost gauge on a naturally aspirated car's intake tube would read 0 psi (maybe a fractional increase, but nothing worth looking at) no matter how it is positioned. As you mentioned, there is a vacuum inside the engine, which as you said is a giant air pump... that's the only real pressure difference. If you held a pipe with a ballon duct taped to one end out the window, it would not fill up the balloon.. The air would occupy the balloon until the point that it needs to be compressed, then "new air" would flow around the contraption.. The pipe might fly out of your hand because the air is at a higher velocity relative to the pipe. Having a large pipe with a small hole on the end is a nozzle.. that's a different story than ram air. Air will not compress itself.