pilchardthecat
Active member
By far the most restrictive part of the OEM intake system is the MAF screen. The pressure drop is several times greater than that either side of the filter itself.
You can't simple remove it though, as it is comprised of two parts, each with a specific purpose
- A thin metal mesh, which is designed to remove the turbulent flow inside the airbox and create a laminar flow in the tube that houses the MAF (this is required for MAF accuracy)
- A thick plastic mesh, which is an "air straightener" that forces the air to run straight down the tube past the MAF (it won't otherwise, partly due to turbulence, and partly due to the velocity stack inside the airbox (the trumpet shaped thing)
If you simply remove them, you will cause turbulent flow past the MAF and seriously degrade it's accuracy
The plastic mesh is the most restrictive part, and is effectively blocks more than 30% of the cross sectional area of the tube
My modification involves
- removing the wire mesh
- cutting away the plastic mesh
- replacing both with a thin metal honeycomb air straightener which acts to both straighten the air and induce laminar flow. This metal honeycomb only takes up about 4 or 5% of the cross sectional area of the tube
The pictures are bit crappy but you get the idea....
Enjoy.
You can't simple remove it though, as it is comprised of two parts, each with a specific purpose
- A thin metal mesh, which is designed to remove the turbulent flow inside the airbox and create a laminar flow in the tube that houses the MAF (this is required for MAF accuracy)
- A thick plastic mesh, which is an "air straightener" that forces the air to run straight down the tube past the MAF (it won't otherwise, partly due to turbulence, and partly due to the velocity stack inside the airbox (the trumpet shaped thing)
If you simply remove them, you will cause turbulent flow past the MAF and seriously degrade it's accuracy
The plastic mesh is the most restrictive part, and is effectively blocks more than 30% of the cross sectional area of the tube
My modification involves
- removing the wire mesh
- cutting away the plastic mesh
- replacing both with a thin metal honeycomb air straightener which acts to both straighten the air and induce laminar flow. This metal honeycomb only takes up about 4 or 5% of the cross sectional area of the tube
The pictures are bit crappy but you get the idea....
Enjoy.
I shall definitely try this mod. I've got a a couple of spare air-filter boxes/MAFs so I'll measure the aperture for the honeycomb screen (from memory its around 87mm diameter) to see what thickness of honeycomb is available. It might be possible to get the seller to produce something bespoke for a group buy?
NO! NO! and thrice No! 
