Quote:
Originally Posted by Skip_1074
When I read the OP, the combination of the Edge and CAI caught my eye while I was still on the first sentence, and I was actually surprised that nobody else mentioned it.
I understand fluid dynamics, but not to the point that I can confidently speak on it. You are definitely right about air being a fluid and it being tricky. I have searched a little today and I can't seem to find an article that I read on Banks Power, specifically addressing air being a fluid, but here a chunk borrowed from one of their articles:
Hampsterzone, you discussed backpressure in one of your earlier posts. As you notice, backpressure actually creates heat excess heat in the engine acting as a "parasitic loss" in power.
As for the time wasting that I did this morning, I was trying to do some calculations in regards to engine CFM airflow requirements in comparison to the ability of air systems to move them, but unfortunately I was unable to find the capability of the stock air system. But just for  and  , the max CFM flow of the 5.4L 3V engine at 5500 RPM is 628 based on the calculator that I have.
I would have gone fishing, except for a few things...its was only about 3:30am when I started the post, around 5:00am when I finished it and I'm pretty sure you can't get your line wet until first light. It was about 25 degrees outside and the closest place to go fishing is a GOOD hour plus away. The only reason that I was still up was my daughter had late start at school and I had to take her so my wife could go to work.
This discussion has been great and I only hope that we can keep the information flowing. If I find the article of air as fluid, I will definitely pass it on. |
In scientific terms, a gas IS a fluid just as a liquid IS a fluid. The confustions arise when things are translated to common speak because words are not the same.
If your wanting flow bench results, we have some in an ancient article...
http://forum.gopowerhungry.com/2004-...t-results.html
At the current state of technology, our engines are pathetic on mechanical efficiency.
Back pressure also reduces engine efficiency because not all of the exhaust gasses are expelled. For gasses, pressure is equivalent to mass. Here we work backwards. Instead of trying to increase pressure at the cylinder, here we are trying to reduce it. If there is pressure out side of the cylinder then more of the molecules that make up the exhaust gas will stay in the cylinder. Things also start getting real tricky because the exhaust gasses start acting a little different because now we are pushing them with pressure rather than pulling them. You encounter simple logic problems such as exhaust pipe diameters and configurations that reduce performance rather than increase it, along with true impact of obstructions and such. If you go on the larger forums you can see people (like me haha) get chewed on for running baffled mufflers like the flowmasters. The baffles present an obstruction and logically would stop or hinder the flow to cause a decrease in exhaust flow, increase heat, etc. All of that sounds true and to an extent is true, I did see a loss in performance because I tested it at a local drag strip. I lost .07 seconds on a quarter mile run. Exhaust requires more advanced understanding of fluids under pressure because it is very easy to overeastimate and undereastimate the effects of a modification without having a solid understanding of the numbers that cause it. I try to not discuss anything unless I'm able to test it because without facts everything is a WAS guess, epecially for this.
