Kitfox Aircraft Stick and Rudder Stein Air Grove Aircraft TCW Technologies Dynon Avionics AeroLED MGL Avionics Leading Edge Airfoils Desser EarthX Batteries Garmin G3X Touch
Page 1 of 3 123 LastLast
Results 1 to 10 of 25

Thread: 912is Sport Cold Air Intake

  1. #1
    rocketman2tm's Avatar
    Join Date
    Feb 2010
    Location
    Kenosha,WI
    Posts
    86

    Default 912is Sport Cold Air Intake

    Here is some data that this group might be interested in.

    I have always figured that the location of the air intake on the 912is is not in an ideal location in a cowled airplane. Putting the intake behind two air cooled cylinders definitely heats the air up some, but I wanted to get some data to know how much. My dad and I installed two thermocouples on the plane; one on the outside of the plane at the wing root and the other right in front of the air filter. I figured if the temperatures were 30 degrees above ambient, it might be worth putting in a cold air intake. They were over 70.

    Temperature.jpg

    Granted, this was only during climb out but that is when full power is needed. Cruise resulted in much lower temperatures. Doing a density altitude calculation my engine is performing as though it is almost a mile higher than the rest of the airplane. At this point it seemed like it was worth pursuing a cold air intake.

    I installed the naca side duct that Kitfox sells. I originally installed this with skeet tubing and immediately knew this is not the long term solution.

    PXL_20220402_170257909.jpg

    So I decided to make my own ducting. I 3D printed some parts out of PVA and tacked them together with super glue. Instead of doing fancy measurements, it was much easier to just trim the parts to length and then figure out the angle while holding the part up to the airplane.

    PXL_20220409_153711413.jpg

    Once the PVA part was complete, I fiberglassed over it. Once the fiberglass was cured I threw the part in a bucket of water for a couple days. PVA is water soluble so after a few days I was left with just the fiberglass part. Below is a picture of the finished installation. Not Mike Patey worthy, but I'm happy how it turned out.

    PXL_20220415_175349754.jpg

    So the moment of truth - What are the results? Without touching the prop and flying on days that are similar temperature and density altitude I am finding that my RPM is about 250 to 300 RPM more than what it was without the cold air intake. My climb out RPM is back in the yellow.
    John Grueter
    N188LR
    Kenosha, WI
    Series 7 Super Sport - flying!

  2. #2
    Senior Member
    Join Date
    Apr 2009
    Location
    Chisholm Mn
    Posts
    1,562

    Default Re: 912is Sport Cold Air Intake

    I wonder how much this will make you likely to have carb icing issues. Not saying it will, just wondering. It does look nice though for sure. JImChuk

  3. #3
    Senior Member jiott's Avatar
    Join Date
    Jun 2010
    Location
    Portland, OR
    Posts
    2,960

    Default Re: 912is Sport Cold Air Intake

    Isn't the 912is fuel injected? No carbs.
    Jim Ott
    Portland, OR
    Kitfox SS7 flying
    Rotax 912ULS

  4. #4
    Senior Member Eric Page's Avatar
    Join Date
    Jun 2020
    Location
    Toledo, WA
    Posts
    863

    Default Re: 912is Sport Cold Air Intake

    Very good intel, John. I'm putting a 912iS in my plane, so this will be something to look at when I'm working on the cowling. Thanks for that post!
    Eric Page
    Building: Kitfox 5 Safari | Rotax 912iS | Dynon HDX
    Member: EAA Lifetime, AOPA, ALPA
    ATP: AMEL | Comm: ASEL, Glider | ATCS: CTO
    Map of Landings

  5. #5
    Senior Member
    Join Date
    Apr 2009
    Location
    Chisholm Mn
    Posts
    1,562

    Default Re: 912is Sport Cold Air Intake

    Quote Originally Posted by jiott View Post
    Isn't the 912is fuel injected? No carbs.

    Opps, I should have read the title better. How do I delete my post??? :-()

  6. #6
    Senior Member efwd's Avatar
    Join Date
    Jun 2015
    Location
    Yorba Linda, CA
    Posts
    2,817

    Default Re: 912is Sport Cold Air Intake

    Greatly appreciated John. I have been considering doing this. I find that I just like to fly the thing these days and although I have things I would like to do, it means grounding it for mods. Where is your Air Filter now?
    Eddie Forward
    Flying
    SS7, 912iS, Garmin G3X

  7. #7
    rocketman2tm's Avatar
    Join Date
    Feb 2010
    Location
    Kenosha,WI
    Posts
    86

    Default Re: 912is Sport Cold Air Intake

    I know the feeling Eddie. The air filter is inside the side NACA duct. I also mounted the MAAP sensor (don't remember the exact abbreviation off the top of my head) in there with it. That way the ECU knows the engine is breathing cooler air as well.
    John Grueter
    N188LR
    Kenosha, WI
    Series 7 Super Sport - flying!

  8. #8

    Join Date
    Feb 2022
    Location
    Godfrey, Illinois
    Posts
    1

    Default Re: 912is Sport Cold Air Intake

    Do you have an air filter?

  9. #9
    rocketman2tm's Avatar
    Join Date
    Feb 2010
    Location
    Kenosha,WI
    Posts
    86

    Default Re: 912is Sport Cold Air Intake

    Yes, the stock rotax 912is sport air filter is located in the side NACA intake. I believe the 915 has the filter located in the side NACA as well.
    John Grueter
    N188LR
    Kenosha, WI
    Series 7 Super Sport - flying!

  10. #10

    Join Date
    Jul 2022
    Location
    Galt, CA NorCal
    Posts
    19

    Default Re: 912is Sport Cold Air Intake

    What kind of climb performance are you seeing with your 912iS? about to pull the trigger on this engine but I read recently that if you are close to gross weight climb performance is about 300pfm...if that.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •