Our Air Bridge acts like a Venturi speeding up the air causing the pressure to Drop and the air to cool.

I have hunted high and low looking for my November issue of Vette Fever. They had a really good article on the subject called "Victory Through Air Power part one."

Just before take-off we perform some last minute engine checks. On a warm humid dad ice can form inside our carburator. On the ramp at engine run-up, when we see the RPM drop we know the carburator heat is working.

Our Air Bridge is a venturi, a bit of GM engineering genious..

"Hello: There are ample resources on the Internet concerning fluid
mechanics related to the Bernoulli theorem and the “Venturi” effect so
here is a quick engineering answer: No matter what energy is applied to cause an increase in velocity of a fluid, the net effect is that the pressure relative to the static state drops and the temperature decreases. In practical applications such as a internal combustion engine carburetor, fuel is drawn because of the pressure differential and mixed with air creating an explosive mixture used to propel the pistons."

In the November article, VF said, air entered the engine at 27 degrees. In the case of the Air Bridge, I am not so sure bigger is better.



Dan

 

In the PCM, there is an adaptive strategy built into the firmware to handle the airflow and compensate for the ripples in the adapter. Changing the airbridge and coupler usually will have adverse effects on idle, decel and surging without some PCM tuning. If you look at the 500 HP 2006 Z06 you will see they still have the accordian style coupler. Untill you go to FI, N20 or 500+rwhp, you will not see any advantage to changing them.

 

The coupler also lets the engine torque freely, The air cleaner is a fix object the engine is not. When to slam the gas the engine moves, the accodrian style allows the engine to move with breaking the air cleaner.

 

If you really want to know if this thing is having a "venturi" effect, then you need to measure temp at the front and back of the airbridge. I would guess there is very little difference. I will do some testing on this.

I am a commercial pilot and a Certified Flight instructor and have been flying different aircraft for twenty years and all carbuerated piston powered aircraft use the venturi effect to draw fuel out of the carb. Some use an aux pump to maintain fuel pressure, but they all use venturi effect. We often have a problem with ice in the carb if the temp is below 70 and the humidity is above 80. That means there can be a 38 degree difference in the before/after temp in the venturi.

Most of these engines have a 3" inlet and a 2" venturi in the carb. The venturi is very radical to help promote the low pressure differential to draw the fuel. A byproduct is lower air temp.

I seriously doubt there much is any difference in temp change in the airbridge on a vette. The venturi effect is just too subtle. There is a bigger venturi effect at the throttle body, that is where you need to focus your attention. You are looking to reduce your air restriction in the intake more than you are trying to lower your air charge temp. If you want a low air charge temp just put on a 60mm throttle body, and lose 50hp, but at least the air going into your engine will be cold.

I am going to do some testing just to prove/disprove your theory, since I am considering a filter and airbridge change on my Z06.

 

was there engine carb or EFI?

 

was there engine carb or EFI?

I gave my November issue of Vette Fever to someone so I no longer have it for reference. Does anyone have a copy?

Dan