What did you take if you don't mind me asking?
I may very well be wrong but the bell mouth that is there causes the flow to be transitioned smoothly just like a ventury tube only the bell mouth does not expand again thus isn't it still part of the ventury effect?

 

not all of our cars have AFMs, i might add...

 

Mechanical engineering. Now I work in commercial HVAC.

A venturi is basically a smoothly contoured restriction. It's not to increase flow. Air entering a straight-cut piece of pipe naturally flows as if a venturi was actually there at the entry, which acts as a restriction.

It's hard to describe clearly without a picture.

 

I'd like to applaud NZ and Jreynish for not blowing up. I totally saw a cockfight coming then I saw something I've never seen on this forum. Jreynish asked a question to see where the difference of opinion was!!! Holy ****!!! You guys should be presidents of nuclear weapon wielding countries!!

NZ I dub thee ruler of China!

Jreynish I dub thee defeater of G. Dubya.

Good Job guys!!!

 

Yeah, It's great to see a discussion that doesn't end up with "You don't know **** dumba$$." and "You're gay." I applaud your intelligence guys.

 

This is the ventury tube (most common) now, the airflow is accelerated when the opening of the tube get smaller for the same amount of air can flow through the narrower part of the pipe. This is just one of the many effects contributed to ventury's theory's! the bell mouth is similar to wind whistleing accross the side of a square building! Am I right?

 

Yep, that's pretty much right. Air entering a straight piece of pipe flows like you've draw. Adding a bellmouth to the entry stops it from contracting like that, and it follows the shape of the bellmouth instead.

Here's an example to show you how effective a bellmouth is. Using 100L/s of air entering a 75mm pipe, the pressure drop at the entry is equivalent to a 3m length of straight pipe. If you add a bellmouth with a radius equal to 0.1 of the pipe diameter that pressure drop becomes the equivalent of a 0.5m length of straight pipe. Even just adding a cone to the entry (much easier to make than a bellmouth) makes a considerable difference.

 

Does the purple color help the flow

sorry .. had to break up the boredom of the topic.

 

yes yes it does

 

In a turbo it helps flow somewhat, but in a NA it can be a big deal.
The S5's VDI is an example of how pulse wave tuning can increase power.

In a NA, you have a pulsed wave intake, and length the tubes can have a significant charging effect.

Check out the variable "trombone" intake on Mazda's LeMans car.

 

Wrong topic.

You're right, but it's not really the length of the tube that's the issue here, it's the shape of the inlet. In this case it doesn't matter if it's turbo or not.