Project E39 M5, Installing the Dinan Cold Air Intake

The BMW E39 M5 is one of the funnest most rewarding cars to drive.  It is also a car without much aftermarket parts support.  Previously we had gotten more power from the S62 engine via K&N drop-in filters and HPS intake hoses.  The K&N filters have less inlet restriction and the HPS hoses get rid of the restrictive corrugated plastic hoses.  This combination got us 7.1 more whp and 2.4 lb/ft of torque.   However, we found out that BMW Tuners Dinan had a cold air intake that should easily improve on our prior results and addresses a problem the M5 has; power fade with temperature. So we had to try one out for our project car.

The Dinan intake has beautiful carbon fiber intake tubes.  They are also very lightweight.  The carbon complements the rest of the engine bay nicely.

High-flowing serviceable air cleaners will sit at the end of the carbon tubes.   There is A LOT more to the intake, but these parts are best shown during the installation. So let’s get to it!

The first step is removing the engine compartment under trays and the front bumper assembly.  You do not have to remove the headlights.  We just had them out to repair the automatic headlight aiming devices that had quit working. Another well know E39 issue. Though having them off the car was helpful, but again it is not necessary.

At this point we discovered a power steering system leak which we will be fixing while we are in there.  You can see the power steering fluid being trapped by the under trays.

6 comments

  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?

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