Just wanted to give a quick update on my custom cabin air filter.
Over the summer the airflow has been good from the system. Granted I have a fan spacer with a bigger squiral cage. It's not great but it's decent and I don't think it needs to be any harder.
The air quality has been great though. The car's been staying cleaner and it's definitely been a great addition plus a great little attention grabbing modification.
I was showing my grandfather the air filter and pulled it out to show him how I made it but also thought I'd check how dirty the filter was after 1500~ miles of driving. I can't believe how dirty this filter is!
I've been posting my winter projects on another thread but I thought this project deserved it's own thread incase anybody wants to do this to their car.
I'm installing a brand new AC system into my car this winter. I removed the evaporator case and I saw quiet a lot of dust in the vents. A lot considering I had just cleaned all of the vents last year. It got me thinking about an idea I had a few years ago of making a custom cabin air filter. I decided I had the time... Quite a lot of time in fact, so I took a stab at it.
I decided to install the filter in the engine bay behind the evaporator. I choose that location because it filter's all of the air. You could probably source a smaller filter and put it in the main vent but if you're using the heater it's possible for unfiltered air to pass into the cabin. I also choose that location because if it got wet there is a drain whole for the evaporator so it should dry up and not get moldy.
First I measured to see what my options were as far as filter's. That would determine the size of my filter frame and how much clearencing I would need to do. I decided on a Wix 24270 filter but you should be able to go with a Fram 11666 (carbon infused filter). I then needed to get some 1" aluminum 'C' channel. The walls of the channel are 0.125" thick which leaves me with a channel width of .75" which happens to be the exact depth of my filter. I then needed to bend the channel to make my frame. I wanted a 7" wide channel but I had to factor in that aluminum stretches when you bend it so I calculated 6 5/8" measurement would give me 7" when bent. I had to heat the aluminum up to 400 degrees Fahrenheit to take the temper out of the metal so I could bend it without it tearing. I learned this neat trick where if you rub some soap on the back side of your aluminum, then you heat it with a propane torch and the soap will turn black when it gets hot enough. I then had to let the part cool down before bending it to again avoid tearing the metal. It actually turned out to be 6 15/16" once I make my bends but it was close enough and the aluminum didn't tear or break. Once I made my two 90 degree bends I used a chop saw to cut the frame to be 10" tall. I then clearanced the box to fit the frame. Once everything was fitting nicely I decided to test fit it in the car to make sure there weren't any clearance issues but there was. My header was only 1/8" away from the box. The only solution was to remove a section of the side of the aluminum channel with a Dremel, a carbide bit, and a lot of patience. I also trimmed the fiberglass to act like the wall of my channel then secured the frame in place using some urethane. Last night I finished laying up the fiberglass to close the box back up. I did a test fit today and I have about a 1/4" of clearance to my header and I haven't sanded down the fiberglass. Next I'll be making a cover for the air filter out of 0.5" x 0.75" aluminum flat bar, then sanding and finishing the box.
I haven't quite got the project done but I'm hoping to have it done in the next week or so and I'll try to keep you guys up to date.