# Fresh air induction **URL:** \ **Category:** Aerovee\ **Created:** [April 1, 2026, 3:06am UTC](https://sonexpilots.org/t/fresh-air-induction/5563 "2026-04-01T03:06:29Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [April 1, 2026, 3:06am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/1 "2026-04-01T03:06:29Z")
The original thread on the old forum was AeroVee Performance (Cold Air Induction) started by our mad scientist friend Wes. Most of my pictures didn’t make make it from the wayback machine import, so I thought I would re-roll the topic. This is the single best mod I’ve done to my motor. I’m going to do an abbreviated writeup but include lots of pictures. Here is the can I wrapped around my filter. You can see it’s nice and leaky - we don’t want to pressurize the aeroinjector because that impedes fuel flow. ![air filter cover 1](https://sonexpilots.org/uploads/default/original/2X/f/f50b7b58ac0847b337abc90c74e78e00e799b57f.jpeg) One of the problems I had was the turbulent air coming up to the carb seemed to divert a lot of the fuel to one side of the Y pipe. I went through a bunch of iterations - are they all required? Not sure but this is what I’ve got. ![air filter shroud with dual inlets](https://sonexpilots.org/uploads/default/original/2X/0/0cb42fba28049c93426f2844f49064c56286dffa.jpeg) Initially I had one inlet, then went to 2 which is sort of a pain. I wonder if the later stuff I added makes this dual inlet unimportant. I’ve got these blockers to keep the high velocity air from jamming right into the filter - bounces off and goes around the can. ![deflector reflector](https://sonexpilots.org/uploads/default/original/2X/4/4df6818f2b024ca3b99b5fc956b6edbd1ca7aa1f.jpeg) This is what the air sees. ![deflector viewed through inlet](https://sonexpilots.org/uploads/default/original/2X/e/eac9aa2eb5ee717180f23aa198b44ec243704482.jpeg) I still had issues, so I made a flow straightener that jams into the air filter. ![straightener 2](https://sonexpilots.org/uploads/default/original/2X/2/2a9966b2167111478011ff01cfb67a9655f35a8f.jpeg) Then I still had issues, and added a tricky one in my elbow. ![elbow flow straightener2](https://sonexpilots.org/uploads/default/original/2X/3/3aeca135b7e8987a4381e64afc6ffe9988e4527d.jpeg) ![upper flow control installed](https://sonexpilots.org/uploads/default/original/2X/8/8f5d1883d6a23a038bfbee41f1f2cdd9e393c89f.jpeg) I messed around with the ends of that to put some swirl into the flow. Totally trial and error, but got the left-right mixture a lot more balanced. ![elbow swirler](https://sonexpilots.org/uploads/default/original/2X/f/f590e9d67acb400ed91084fa1e36d791084befa4.jpeg) ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [April 1, 2026, 3:14am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/2 "2026-04-01T03:14:53Z")
So after I had the can, I needed to get air to it. I glued together some pink foam I had laying around and did a rough saw job. ![inlet sawed](https://sonexpilots.org/uploads/default/original/2X/c/c48ab2ee9510e839cd5649c7aaca016506c8ca1d.jpeg) Off to the Craftsman vertical lathe and drilling machine. ![inlet mounted in drill press](https://sonexpilots.org/uploads/default/original/2X/d/d6bf49ef808a5d50365d92105f4d7278d887d07f.jpeg) In that picture the arbor is the holesaw I used to punch the hole through the stack. Then I sanded it roundish. ![Inlet sanded](https://sonexpilots.org/uploads/default/original/2X/7/710cba1e953165639b8272f57785a6aeb6e82020.jpeg) I did a little hacking to get it to sort of fit on the cowl. You can see I’m going for the Rutan asymmetry look. Besides the cowl splits in the middle. ![inlet trial fit](https://sonexpilots.org/uploads/default/original/2X/c/cac192649684ce1b87e6b5fb22ce25cb7cada5ea.jpeg) Time for fiberglass. ![glassed inlet](https://sonexpilots.org/uploads/default/original/2X/c/c9d1a115a8283c14956737f66e2b2b9b6e2f6f3f.jpeg) I made a tube to go in the inlet - that’s what my scat ducting will slip onto later. ![inlet with tube](https://sonexpilots.org/uploads/default/original/2X/6/692c8195e25f791845ac95cac885ed9654a0000f.jpeg) Then it gets bonded on - just bodywork and paint to go. ![inlet sanding progess](https://sonexpilots.org/uploads/default/original/2X/3/3afcd305fb93a3f4f9fe5f2309a80475bc250e5d.jpeg) ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [April 1, 2026, 3:22am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/3 "2026-04-01T03:22:36Z")
I added a rubber flap to my designed in leak. ![flap closed](https://sonexpilots.org/uploads/default/original/2X/5/5dccd417832c0b0875eb3272129616cba23547f1.jpeg) The idea is it can flap out if there is too much air, or in if there is not enough. ![flap open](https://sonexpilots.org/uploads/default/original/2X/4/4f0e6cf21efab30921b6a1629baf8c39f8807f91.jpeg) Here’s my hose connected to the air filter can. ![y pipe half installed](https://sonexpilots.org/uploads/default/original/2X/e/e29d31a7b49dc98ec3a73f4aff599de05773feb5.jpeg) I put the right side cowl on first, and hook up the hoses. The second short hose in the back goes to my oil cooler exit reverse scoop. ![y pipe installation](https://sonexpilots.org/uploads/default/original/2X/7/78e5d1b033544e39744d1ad83d914eb01ae43152.jpeg) So - was it worth it? OH YEAH! On my first flight with this I picked up something like 150 static and climb RPM. Definitely better climb performance. Originally I had a climb prop and after doing this plus a few other mods, I was under-propped. Would climb awesome - I’d see 3300-3400 in climb. But we were stuck at 100kts cruise. These days I’m seeing a little under 3100 in climb, but we have seen a 500 fpm average to 7500’, and we are getting 120kts in normal cruise. ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [April 1, 2026, 3:25am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/4 "2026-04-01T03:25:14Z")
![Screenshot_20260331-222433](https://sonexpilots.org/uploads/default/original/2X/9/9af141a27c7a312ac337a31337f552cc7b87684d.jpeg) ![Screenshot_20260331-222403](https://sonexpilots.org/uploads/default/original/2X/9/95bb31bd651a43660f589da45650ae8d334230f6.jpeg) I have found one issue with the fresh air induction though. The first time I flew when it was really cold, like 0-10F, it ran really poorly. Still made RPM but was missing badly. What I have figured out, I think, is that a lot of really cold air makes the 100LL vaporize poorly. It’s probably being ingested into the engine as little blue ice cubes. So I tried a few blockoff options for the inlet, from 100% blocked to the two configurations shown above. Still fine tuning, and we are done with 0F for now, but I did get the airplane to run well in cold temperatures. The rubber flaps & built in leaks allow the engine to pull warm air from under the cowl. ---
**Author:** ![ddeford](https://sonexpilots.org/user_avatar/sonexpilots.org/ddeford/32/855_2.png) [@ddeford](https://sonexpilots.org/u/ddeford)\ **Post date:** [April 1, 2026, 11:21am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/5 "2026-04-01T11:21:01Z")
Pretty awesome stuff Bryan. ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [April 1, 2026, 12:20pm UTC](https://sonexpilots.org/t/fresh-air-induction/5563/6 "2026-04-01T12:20:37Z")
Thanks Dan! Also if anyone wants to post their solution in this thread, feel free. There were a few good ones on the old forum. That’s where I got my ideas from. ---
**Author:** ![q2rd2100](https://sonexpilots.org/user_avatar/sonexpilots.org/q2rd2100/32/1761_2.png) [@q2rd2100](https://sonexpilots.org/u/q2rd2100)\ **Post date:** [April 1, 2026, 4:48pm UTC](https://sonexpilots.org/t/fresh-air-induction/5563/7 "2026-04-01T16:48:00Z")
I second Dan. Terrific info. Thanks for posting Bryan! ---
**Author:** ![Karmarepair](https://sonexpilots.org/letter_avatar_proxy/v4/letter/k/2acd7d/32.png) [@Karmarepair](https://sonexpilots.org/u/Karmarepair)\ **Post date:** [April 2, 2026, 2:23am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/8 "2026-04-02T02:23:51Z")
Is your elbow 3-D printed? If not, where did you source it? ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [April 2, 2026, 4:23am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/9 "2026-04-02T04:23:37Z")
Nope! Silicon elbow: > **[Amazon.com: X AUTOHAUX 57mm 2.25" ID 90 Degree Elbow Silicone Reducer Hose...](https://www.amazon.com/AUTOHAUX-Silicone-Reducer-Coupler-Intercooler/dp/B09DGMYXLH)** > > Buy X AUTOHAUX 57mm 2.25" ID 90 Degree Elbow Silicone Reducer Hose Silicone Hose Coupler Intercooler Tube Black for Car Intercooler Intake Piping: Hoses & Hose Clamps - Amazon.com ✓ FREE DELIVERY possible on eligible purchases ---
**Author:** ![WesRagle](https://sonexpilots.org/user_avatar/sonexpilots.org/wesragle/32/1450_2.png) [@WesRagle](https://sonexpilots.org/u/WesRagle)\ **Post date:** [May 20, 2026, 4:48am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/10 "2026-05-20T04:48:26Z")
Hey Bryan, What air filter did you use? Did the above elbow fit the AeroInjector and the filter well? Thanks, Wes ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [May 20, 2026, 11:23am UTC](https://sonexpilots.org/t/fresh-air-induction/5563/11 "2026-05-20T11:23:30Z")
Wes, I used a K&N RD-0720. [https://www.amazon.com/gp/aw/d/B00029WZCK](https://www.amazon.com/gp/aw/d/B00029WZCK) The elbow fits nicely on the OD of the AeroInjector. I trimmed it so it doesn’t go too low. I jammed the other side into the ID of the filter, put 4 little brass screws through the filter and elbow, then put a hose clamp around it. I screwed a tab on the back of the filter and have a loop of safety wire going from the hose clamp over the frame to the tab to support the overhung weight. I’ll have to look for those pictures. ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [May 20, 2026, 12:26pm UTC](https://sonexpilots.org/t/fresh-air-induction/5563/12 "2026-05-20T12:26:26Z")
![induction screws](https://sonexpilots.org/uploads/default/original/2X/8/8f8ee25e4bdb4154ca438c83e05306295dde814c.jpeg) ![filter internal safety wire thing](https://sonexpilots.org/uploads/default/original/2X/f/f0812f37b4e20644afcef57738b5c8c9ed360fab.jpeg) ![captive induction screws](https://sonexpilots.org/uploads/default/original/2X/7/75ecce7919cd6fbaba033d49d095098385d3facc.jpeg) ![filter external safety wire thing](https://sonexpilots.org/uploads/default/original/2X/c/c0052d4330f7597db51efb544c81ccb95f6f1077.jpeg) ![air filter safety](https://sonexpilots.org/uploads/default/original/2X/3/3d08db922c5e95c528c386c8c8a9d2fc3d637bd3.jpeg) ---
**Author:** ![WesRagle](https://sonexpilots.org/user_avatar/sonexpilots.org/wesragle/32/1450_2.png) [@WesRagle](https://sonexpilots.org/u/WesRagle)\ **Post date:** [May 20, 2026, 1:06pm UTC](https://sonexpilots.org/t/fresh-air-induction/5563/13 "2026-05-20T13:06:45Z")
Thank you very much! Wes