3D Printing an Oil Cooler Duct With BD Engineering

Here is how the duct fits up against the cooler while still allowing the air from the lower vent to access the cooler as well.  We have probably increased the airflow to the cooler 10 fold!  The Greddy oil cooler kit has a sheet metal baffle plate that helps direct the air from the lower scoop to the cooler and now it also has direct airflow from our scoop too.


Our car does not have oil temperature logging but we instead logged water temp using our Access port.  In our experience, oil temp is usually slightly higher than water temp and reducing oil temps also reduces water temps. In our testing so far, for street driving the scoop made very little difference which is what we expected.  When driving on the highway we found that water temps are reduced 5-10 degrees from 70-80mph!  In fact when driving with an ambient temp of 71-74 degrees at 70-80 mph our coolant temps ranged from 168 to 174 degrees!  This is really cool and we will probably have to run the stock cover for winter driving to avoid overcooling the oil! We love the way the duct came out and can’t wait to see what the impact is on our oil and coolant temps during the next track day!  We think the scoop will give us about 10 degrees more thermal headspace on the track.


Greddy @ MotoIQ

BD Engineering

Bells Autosport


  1. The trouble with the Aesub spray is it is pretty pricey at $40 a can. Back when I last did a scanning project a couple years ago it was closer to $60. I ended up using Magnaflux SDK-S2 developer which was a little better at a little under $30 a can, but still expensive. It doesn’t evaporate on its own, but leaves behind a chalky residue that is easy to clean up.

    That said, it seems the real budget option is to go for talc, corn starch or baby powder mixed with rubbing alcohol. I haven’t had a chance to try this myself, but plan to use it at the next opportunity.

    1. The disappearing feature is pretty good for me and worth the price to me especially when doing stuff like suspension, brakes and inside of the the core support, the cleanup would take a long time.

  2. That’s really cool, what a great use of 3D scanning and printing. I’m really glad you guys showed how much work goes into finishing a printed part to an OEM level finish. The finished part turned out great!

  3. > This is really cool and we will probably have to run the stock cover for winter driving to avoid overcooling the oil!

    Is there reason not to run an oil thermostat sandwich to the cooler to avoid overcooling?

    Great article!

    1. I don’t like them as they can restrict flow, however, the Greddy cooler uses one. I am not sure what temperature it opens at.

    2. On Project S2000, I had to cover up some of the front bumper airflow opening in winter taking the highway to the track to reduce airflow to the oil cooler. Even though I had a Mocal thermostatic sandwich plate, it still always flows some oil. If the oil in the oil cooler were completely cut off, then it would be very cold when the thermostat opened up and could thermally shock hot components it comes in touch with.

  4. What polymer was the component printed from? Fantastic work on getting the fitment and then surface finish so good.

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