PeachParts Mercedes-Benz Forum - View Single Post - Modification for D-Jet M116 and M117

Greg in Oz · #12 04-22-2005, 03:54 AM

Ysmael,

I'm pleased you gave this a try and also noticed some improvement. Mount Kiera is certainly a good test!

I would expect even better results if like me you eliminate the narrow end of the intake pipe to increas the cross-sectional area to match that of the 80mm flex pipe. I would also expect that the mesh you fitted at the intake would also cause some restriction.

I probably would not be too concerned about fitting mesh since the filter element is designed to stop everything from bugs down to dust. I would be a little concerned with having the intake down as low as the towing point though. You never know when you may encounter a deep puddle or a flooded road and an intake this low is risking serious water ingestion. I would also expect more dust would be encountered this low down.

I have not studied a 108 with a view to fitting a cold air intake, but is there either sufficient space next to the radiator behind the grill or alternatively is there a gap under the leading edge of the bonnet where it closes down onto the panel between the grill and headlight? Maybe an intake could be fabricated with a narrow oval shape. Just so long as the cross-sectional area is no less than an 80mm pipe.

As to any benefit from a ram effect at speed, I am not sure. The issues Tomguy raised may well come into play here. It really depends upon whether the fuel mixture remains correct when the manifold pressure is slightly higher as a result of any slight ram effect combined with the enlarged cross-sectional area of the intake. Hopefully it will still be within the range of the MAP sensor and the injection system can provide any additional fuel required. I feel that only exhaust gas analysis under true driving conditions would confirm this. The tendency for D-Jet to run somewhat rich at least provides some safety margin.

Greg