Filter or no filter
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From: Temecula
Filter or no filter
I just put my turbo back in my car and I have a short pipe with a k&n filter on it. When I had that on my car seemed to spool up at around 4k. I took that off and put just some aluminum screening on there but now it seems to spool at almost 5k. The screening has kind of fine holes like a screen door material. I thought having no filter or piping would get me better response but it seems opposite. Any ideas as to why?
Joined: Apr 2006
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From: Clifton, NJ
This came up once before. There was a thorough analysis and write up done, and the result was running an intake cone was better than running nothing.
Edit:
I found it, courtesy of user "Artisan7471"
Edit:
I found it, courtesy of user "Artisan7471"
When you add a screen you effectively reduce flowable area, because the screen mesh takes up space in the intake track. So by the continuity of mass principle the air entering the turbo will now have to flow at a higher air velocity to maintain a similar airflow. And because the coefficient of drag varies as the square root of air velocity, the marginally higher air velocity now has a much higher loss coefficient when flowing through the screen. For example if you take a turbo inlet and add a screen that reduces the flowable area by half, the new air velocity now has to be 2 times as fast to maintain similar airflow, however the new applicable coefficient of drag is 4 times as much eek3.gif .
Now the air filter on the other hand, does the exact opposite of a screen. Most good air filters have a large surface area of filter membrane. The reason for this is that, the larger the flowable surface area, the slower the air can pass through and still maintain a good flowrate. This is good because, then your losses due to drag are much smaller, and also dirty air is much easier to filter at lower speeds.
So Yes, a screen can reduce your airflow.
Now the air filter on the other hand, does the exact opposite of a screen. Most good air filters have a large surface area of filter membrane. The reason for this is that, the larger the flowable surface area, the slower the air can pass through and still maintain a good flowrate. This is good because, then your losses due to drag are much smaller, and also dirty air is much easier to filter at lower speeds.
So Yes, a screen can reduce your airflow.
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