pilchardthecat's MAF screen mod

[pilchardthecat]

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.

[AlienZed]

Will have to try that .where do u get the tube honeycombe section from.
Moz

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[Bumpy]

Will have to try that .where do u get the tube honeycombe section from.
Moz

Sent from my GT-I9300 using Tapatalk 2

+1
Bumpy

[pilchardthecat]

I got mine here www.saxonpc.com/100mm-cells-for-100.html
You need the 4:1 ratio, and will need to trim to the correct diameter

[AlienZed]

Cheers for the info.now to get some
M

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[Z4M-2006]

What gains are obtained by doing this,apart from increased flow?

[pilchardthecat]

It works well with a couple of other mods I will share later (i made a carbon fibre intake ram/scoop for example). Throttle response is improved.

I also did some smoke/dye airflow tests, and the airflow over the maf is considerably smoother, which in theory will improve the accuracy of the output signal.

Surprisingly it sounds slightly better too.

I havent dyno tested it. I would be interested in any dyno/datalogging if anyone else decides to have a go. It costs about £12 and takes all of 10 minutes to do.

[Z4M-2006]

Superb....

Between you and Exdos these "cheap" mods will soon relinquish 350bhp...

[pilchardthecat]

I think the combination of the maf screen + exdos "eureka" mod + ram scoop + free flowing exhaust will add 15 horses yes

Its a much better approach than a hot air cone filter (i have some inexpensive induction some noise mods that I will share too)

[Z4M-2006]

How much do you think the exhaust hinders if you do all the intake mods..?

I quite like the exhaust sound as it is..

[pilchardthecat]

Exdos has done some datalogging on that subject, he is better placed to answer than me, but i have only recently fettled with the exhaust and certainly noticed improved pick up and throttle response from the ram scoop and the MAF screen

[AlienZed]

[quote="pilchardthecat"]It works well with a couple of other mods I will share later (i made a carbon fibre intake ram/scoop for example). Throttle response is improved.

Any pics please
Moz

[pilchardthecat]

This is my cheapo induction noise mod.

Basically it involves making a super-thin carbon fibre skin for the outside of the top part of the air box, then cutting away parts of the thick plastic of the airbox and sealing back up with the carbon. My original plan was to fabricate a complete OEM airbox in carbon fibre, but i was so pleased with the results of this i still havent bothered to take the next step, as it would be very fiddly

The process is basically
- make a glass fibre mold of the airbox
- cut this down and use it as a template for the carbon
- Cut some nice big holes
- Stick the thin carbon "skin" on with resin

Result = lots more induction noise whilst completely retaining the efficiencies of the OEM intake system.

[exdos]

pilchardthecat,

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?

[pilchardthecat]

I am very interested in any datalogging results you get