DIY : How to increase airflow to your stock throttle body

[Championship White]

So what you're saying is that when the air passes through the reduced diameter and speeds up it also decreases in pressure and this then causes the higher pressure air behind it to move down the gradient and effectivley 'pull' it in?

Can I have my degree now?

 

[JDMdude]

So what you're saying is that when the air passes through the reduced diameter and speeds up it also decreases in pressure and this then causes the higher pressure air behind it to move down the gradient and effectivley 'pull' it in?

Can I have my degree now?

Bingo bango.... your Degree is in the post

Yea that's pretty much it, the diameter has been reduce but the pressure on the filter side stays constant so therefore the air flow is forced to speed up, once through the bottle neck the air maintains its new faster speed but because the diameter has been increased again (but the air is now flowing faster) this causes the pressure to drop aka a vacuum is created, effectively sucking the air through the smaller diameter but as I said above a minimum air pressure between the filter and the reduced diameter has to be maintained (from a sealed/ram air type intake) other wise the air will not to speed up and the system will actually just become a restriction.

Sorry tried to keep it as untechnical as possible, basically if your standing too close to the road and a lorry goes hurtling past you feel it suck you out towards the road after it goes past, same basic concept.