2014 Subaru Forester – Custom Fiberglass Snorkel Build


Weighing the Benefits:

First of all, I live in Arizona, so deep water crossings are few and far between. I don’t go looking for trouble, but I don’t want to suck water on a 24″ crossing, either. The OEM air intake on our Forester is directly behind the grill and the “snorkus” bottle on the air filter box was not intended to handle the large amounts of water likely in a water crossing. Additionally, snorkels shift the air intake to roof level, where much less dirt and debris is likely to be ingested. Since this particular Forester spends up to 50% of its time on desert roads and trails, that is a real concern.

Built vs. Bought:

There are several companies in the aftermarket industry that make rock-solid snorkel kits for a wide array of vehicles…unless you are shopping for a Subaru. At this point, no companies are producing snorkel kits for the SJ Forester -or any other Forester- to my knowledge. Shocking, I know.  Some very creative owners have developed some great methods for adapting snorkel kits to their Subarus, but, unfortunately, the SJ Forester is a unique body style that made adapting an existing kit much more impractical.

So we’re building a snorkel. How hard can it be, right?

Googling “homemade snorkel” yields hundreds of entertaining projects. There are a lot of ingenious wheelers out there with some amazing PVC contraptions. However, I wanted something that fit the car a little better and didn’t make me think of sewage pipes. Eventually, I found a build thread by a guy in Iceland.(His Project)  He made his snorkel from fiberglass using foam pipe insulators and expanding foam for his mold. The end product was a bit more “organic” than I wanted, but the concept was solid. The next step was adapting this process to my Subaru…

After spending some time under my Forester’s hood, I came to 3 conclusions:

1) The OEM air box & integrated snorkus was not compatible with my plan. It is not a sealed unit and sealing it would require re-sealing it each time the filter was changed. The filter would need to be in-line or external.

2) The passenger fender well is packed tightly with support brackets that I was loathe to cut or navigate with snorkel ducting. That meant a system to pass through the hood or route the snorkel all the way to the bumper fascia.

3) The intake manifold is a 3″ pipe beginning at the MAF sensor, so that would be my minimum diameter for my snorkel design. Also- MAF will need to be incorporated. Car throws codes and goes into safe mode without it.

Let’s Get Started:

After a few beers with a buddy and tossing ideas back and forth, I decided a foam pool noodle was the best option for a mold and that I would rather enter through the bumper than devise some crazy mechanism to pass through the hood.

Initial mock-up:

Snorkel Mock-up


Once I was happy with the lines, waxed the area and covered it in blue painters tape to protect the finish. Then I coated the blue tape in clear packing tape, to which fiberglass will not adhere.


Once the car was fairly well protected, I laid 2 coats of fiberglass cloth  in a 2″ strip along the route of the snorkel and soaked with fiberglass resin.  Be sure to push out all the air bubbles and make it a uniform coat

Initial Application

Initial Application2

At this point, I still had no idea, what the filter mechanism would look like, or how I was going to pass through the bumper fascia without creating a total mess…so I just left the ends alone for a bit.

Once the base had completely cured, I scored and wrapped the noodle with clear tape, then attached it to the car using blue tape to hold it in position. With the noodle in place, we began wrapping it in 2″ strips of fiberglass then soaking with resin, and removing the tape as the glass cured, gluing it to the base. We repeated the process until the entire noodle was mummified and one with the base strip.

Pool Noodle1

Pool Noodle2

It was about this point I decided upon a conical air filter. There were several options for mounting it, but all of them have their drawbacks. I decided to face it forward, which created a U-bend in the pipe, but allowed me to best support and protect the filter.

Pool Noodle3

Pool Noodle4

While shopping at O’Reilly’s for the filter, I also discovered they sell DIY cold air intake components in 3″ OD. Perfect! I purchased a 4″ straight pipe and a 90-degree elbow. The 4″ straight pipe was glassed into the top, giving me a perfect mounting surface for the filter and the 90 elbow was glassed into the bottom and passed perfectly through a 3″ hole in the bumper. Eureka!

Once the glass was finished, it was time to split the mold. Using a simple jigsaw, we cut the mold nearly in half, allowing us to pull the noodle out.

Breaking the Mold

Once the noodle was out, we drilled 2 holes through the back of the snorkel and through the fender for mounting studs. We glassed the heads of the bolt into the snorkel body, so I only need to loosen the nuts inside the fender for removal. I also used a bit of aluminum mesh to reinforce the area around those bolts and in the bends of the main tube. This image shows some aluminum mesh I glassed into key points for additional reinforcement.

Mesh Reinforcement

Once the snorkel had fully cured, it was finally time to “break” it off the car. It was a bit hair and a bit violent, but in the end, it popped off better than I could have hoped for. The time spent in prep protected the car brilliantly. Not a single drop on the paint!

It was at this point that a long and difficult project became pure hell. It was time to sand the fiberglass snorkel. Tyvek suits, more gloves, booties, goggles, masks and some 90 Arizona sunshine. Yuck!

I found an angle grinder to be the best option for cutting away the excess base and removing the highest points. My buddy was simultaneously hating life while running a belt sander with 36 grit.

This pic shows us about 2 hours into that process, but also gives you a peak at the fender studs and piping.


More sanding. Pure Misery.

Sanding Hell

Honestly, I should have spent another 4-5 hours finish sanding, color sanding, and possibly even applying a coat of bondo for an automotive finish. But I was in agony. I have 3 herniated discs in my back and they were screaming in unison by the time I tapped out. The final finish suffered greatly for my frustration. Also, because the damn thing managed to fall off the table and into the grass twice while I was painting it with bedliner. I’ve already accepted that my OCD will eventually force me to strip it and refinish it in the near future. I intend to swear mightily the entire time.

Anyhow…With the snorkel painted, it was time to address the filter. It would be quite embarrassing to build a snorkel capable of deepwater crossings only to be drowned out at the first hard rain. I needed a shroud. A plastic flower pot just happened to fit perfectly with a bit of trimming.

Flower Power

The pot has a 1″ larger diameter all the way through, allowing for 1/2″ of airflow all the way around when attached. It is easily removed, should I ever feel the need.


At this point, the snorkel was essentially complete. The last phase of construction was under the hood. A bit of DIY CAI flex pipe mated perfectly (as intended) to the 90 elbow inside the bumper, but then I had to find a solution for the MAF sensor. I took the MAF sensor to O’Reilly’s in search of a solution, but nothing fit correctly…except for that one thing I had at home!

Airbox MAF

30 seconds with a hacksaw and I had my custom MAF sensor housing… in the same 3″ diameter!

Airbox Delete

Et Voila!



I love how it hugs the side profile, which is ridiculously complex, when you stop to really look at it.

Total cost is right at $275.00

Happy Trails!


2014 Subaru Forester

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