This measures are good choosen so the box will fit into space left when old filterbox and its bracket is removed.
The Fuelfilter is easily pushed away slightly to give full space.
Frontplate , where 100mm diam. connection for hose is made is 280mm long and 170 mm high.
Total depth of the box including radius at back is 180 mm.

This is about maximum space in all directions. Filter is now shielded from hot surrounding air and feed from a 100mm diam. hose from underneath. My material is Makrolon, but any thin material of 1mm alu etc. can be used.

By using Makrolon it was easy to build the box and also easy to check if when the filter gets dirty !
I saw on the German BBS that there where mentioned K&N and Pipercross - note that BOTH filters can be used
Both use oil to keep dustparticles ! For both there is a kit with cleaner and oil in spraycan availiable.
I also have an extension that samples air and gives some overpressure into the box. When later car is on a real ramp more pictures will follow.
all the best ,

Carl, Sweden

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Added by Dieter,
IMO this box can be applied too to the existing 57i installation. The small 57i filter element requires only a smaller box., special at mpi engines some friends shortened already the connection rubber hose to alter the probably working resonances. A good solution can be too the use of the
K&N X-stream Filter Typt T, RX5022. See my air filter collection Webside for actual known performance filters for our MGF