Project E39 M5, Installing the Dinan Cold Air Intake

First, the factory air boxes have to be removed.  We started by removing the lower coupler to the air ducts.

There are air ducts that pick up cold air from the front of the car and guide it to the air box.  We are actually pretty impressed with the stock air intake system, it is pretty much designed for good flow from the factory. It will be interesting to see if Dinan can significantly improve on the factory parts.  We remove the first hold-down bolt near the front of the duct.

Next we remove the second duct hold down bolt.

Now the duct can be removed.

Next, the lid of the air box is snapped off, this is a service item for the air filters so it removes very easily.


  1. Schrick cams and a lightweight flywheel, please. VAC Motorsports has both. They really transform the car.

    1. My experience with rwd & light flywheel, it’s most nticeable in only 1st gear, when revs build up quickly .. it’s less rotary inertia at engine speed accelleration. I found I would spin the tires more easily at take off. It may improve heal-toe shifting, depends on several other things like throttle response. Good cam up grades are winners, have done a few.

  2. Great install write up.

    It looks to be very well made, but based on the Dinan site, not sure it’s worth the trouble and expense.

    “More Power: + 5 HP @ 7000 RPM, + 4 LB-FT @ 7000 RPM (coupled w/ engine software).”

    A BMW M5 is likely to have a good intake already.

    1. We noted that the stock intake was a pretty good design. The biggest part of the equation could be relocating the intake air temp sensor as power drop due to the sensor getting hot is a pretty big deal on these cars.

      1. Out of curiosity, I would measure the air temp entering the manifold , vs at the MAF sensor, after heat soak. If the same, the hot retarded timing may be justifed for engine health?

  3. Did we ever compare these to the stock intakes
    On the dyno? I have the same set up with headers debating adding these.

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