Introduction: How to Install a Car Snorkel

By http://darrenlewismechatronics.c

This guide explains in detail how to fit a snorkel to your car to give you super fun times driving through deep water and smugness knowing your car is breathing cleaner less dusty air.

PS: If you do plan to cross deep rivers consider waterproofing your starter motor and extending your diff breathers.

Supplies

To do this you will need:

  • A snorkel kit designed for your car. I couldn't buy a snorkel that was designed for my car so I had to buy one for a similar car and adapt things, the snorkel I bought is linked here and my car is a Mitsubishi Challenger also called a Montero Sport, Pajero Sport or Shogun https://www.ebay.com.au/itm/254402503990
  • 2 different hole saws. I used 86mm and 95mm but you should measure your snorkel to decide what size your holes need to be
  • Drill bits sized for the fender studs and the pop-rivets, I used 5mm for the pop-rivet holes and 10mm for the M8 studs (it's good for the hole to be a bit bigger than the studs to give some clearance and room for error).
  • Some automotive grade silicone sealant. Any old silicone sealant will probably work but automotive sealant will be a bit tougher and rated to withstand higher temperatures.
  • Rubber edge strip to cover sharp metal edges. For example see link: https://www.clarkrubber.com.au/products/15571-weather-strip-u-channel-1-5mm-x-10mm
  • Some body coloured paint in a tester pot.
  • If you are having to modify your car's airbox because your snorkel wasn't designed for your car (like I did) then you will probably need some extra parts. I had to additionally get the following:
  • A short length of 75mm drain pipe which is just the right diameter for the snorkel's flexi hose to fit onto.
  • A plumbing flange-adapter which I used to relocate the air resonator.
  • A plastic disc to cover up a hole in the air box.
  • Some very strong plastic glue example in following link: https://www.supercheapauto.com.au/p/selleys-knead-it---aqua-50g/285051.html
  • Some brake cleaner or other evaporative cleaner and cloth for throughly cleaning surfaces before gluing.

Step 1: Drill the Big Hole

If your template was anything like mine then it will be wrong about the position of most of the holes however the position of the big hole it got pretty close, I learnt later that it would have been better to drill the hole 5mm or so higher. In my opinion marking out the big hole was the hardest bit of the job, so do take your time and use several different methods to mark out this hole and triple check it. I started by marking the template's position of the hole on the car's fender with long vertical and horrizontal lines (like a cross-hair), then I held the snorkel in position with my hand and got it as close as I could to where it would match the contours of the bodywork, then I looked at it from directly from the front and straight above to see how closely the big tube of the snorkel matched up with the cross-hair mark and adjusted it accordingly.

Something I would try if I did it again is to make my own template out of corrigated card. I would do this by replicating the side of the snorkel that contacts the bodywork in card including the shape of the curves of the body work, then I could stick this directly to the bodywork to get a pretty good idea of where the hole should go.

Hole saw sizes:

  • 80mm for the outer fender (I used 86mm but it was a little too big in my opinion. The plastic tube of the snorkel was 75mm)
  • 100mm for the inner fender (I used 95mm but in hindsight some extra space would be nice to prevent vibrations from wearing the flexi-hose). I bigger size will work too, but not smaller as any smaller than 95mm it will be a struggle to push the hole through which means the flex-hose in your kit will rub against the hole and might break through over time stopping your setup from being water tight.

Try not to drill to fast or press too hard as the extra heat will damage the hole saw and warp the cut. Slow and steady and take your time. Use some coolant or cutting fluid if it starts to get very hot.

Step 2: Debur the Hole and Paint Edges

  1. Use files/sand paper to remove all of the bur (sharp edges) until it feels nice and smooth on your fingers with no sharp edges.
  2. Use your paint to touch up the edges to prevent rust to make it look nice. Use several coats. I used body coloured paint but any automotive body paint will work. An extra tip is to apply a rust prevention solution before the paint, should be available from any good automotive parts store.

Step 3: Rivet A-pillar Bracket

  1. Once your paint has dried, hold the snorkel into position with the air-box tube of the snorkel pushed into the big hole that you drilled. Then mark out the position of the angled bracket on the A-pillar next to the windscreen.
  2. If you have a friend then get them to hold the snorkel still in the right position, but if not you can do what I did and tape it in position.
  3. Take a good look at the snorkel from all angles to make sure you have it positioned just right to match the shape of the car body.
  4. Cut a piece of tape the same length as the bracket and carefully stick it on the car to mark out the target position of the bracket.
  5. Remove the bracket from the snorkel and hold the bracket on the car in the correct position along side your tape marking. Mark out the holes in the bracket, centre-punch the marking then drill out the holes. Use a drill bit that is a fraction of a millimeter bigger than your pop-rivets.
  6. Insert the pop rivets into each hole to make sure the holes are in the correct positioned.
  7. Pour a good blob of silicone around each hole to water proof the holes. Don't want any rain getting in there do we.
  8. Then pop the rivets.
  9. Test the positioning of the snorkel by attaching it to the bracket with the provided screws. If it's not quite in the right position then you can file out the bolt holes in the bracket to adjust a bit, I had to do this because the bracket holes didn't match up with the threads in my snorkel.

Step 4: Drill Fender Holes

Ok this next bit is tricky again because you'll need to mark out holes in something that you can't see though... again. But this time it will be easier because the snorkel is already in position.

The template that came in my kit had the fender hole markings in completely the wrong places. I tried adapting the template to correct the hole positions, that didn't go well so I had to get inventive and I found a pretty good method of aligning the holes, see below:

To mark out the fender holes without the template:

  1. Insert the studs all the way into the snorkel.
  2. Place some pieces of tape on the car fender where the holes need to go. Be sure to use a soft compressible tape, I used duct tape.
  3. Push the snorkel into the fender with some force so that the studs make a dent in the tape and hey presto you have marked out the hole positions! Not too hard eh?

Centre-punch the hole positions then drill out the holes. My studs were M8 and I used an M10 drill. I started with a 3mm drill then used progressively larger drill bits until I got to 10mm, this will help you keep an accurate hole position and help to prevent the drill from drifting.

Step 5: Debur Holes and Paint Edges

  1. Remove all the sharp edges using files and bits of sand paper as you did before until the edges are completely smooth.
  2. Paint over the edges.

Step 6: Attach Snorkel

  1. Splurge a generious amount of silicone around all holes.
  2. Hold the snorkel in position.
  3. Tighten all screws, studs and nuts.
  4. Look for any unsealed parts of the holes and squirt in silicone until all gaps are filled. The aim here is to prevent rain water from entering the fender through the holes that you drilled.

If your snorkel is designed to fit your exact car then skip to step 10you lucky son-of-a-gun, if not then go to step 7.

Step 7: Mark New Hole in Air Box

Well well, if it isn't Mr/Ms ambitious wanting to fit a snorkel that's not designed for your car! It's very acheivable providing you don't mind cutting up your air box.

  1. Decide how you want to do this... Ok so that might sound obvious but there will almost certianly be multiple ways that you can arrange new piping and reconfigure things. I've seen a few other people's posts about attaching a snorkel to a mitsubishi challenger like mine, and some people did some not ideal things that I wanted to avoid including:
  2. Using a longer than necessary tube with multiple bends. Longer tubes and additional bends will introduce a pressure loss meaning that energy will be lost and this will reduce your car's power, maybe not by lots but I would rather maintain as much Bhp as I can.
  3. Deleting the resonator box. Not everyone may understand what this seeminly simple plastic box is doing there, some people remove it because they like the extra induction noise made by the gapping hole in the air box, in actual fact Mitsubishi (in this case) put it there for a reason, it works like a Helm-Holtz resonator to dissipate unwanted pressure waves that are created by the piston action of your engine and helps your engine run smoother, more responsively and increases power. This articles explain it in more detail: https://getjerry.com/car-repair/air-intake-resonator#how-to-save-money-on-your-car-insurancehttps://www.quora.com/What-is-the-purpose-of-air-intake-resonator I drove my car both with and without the resonator after installing the snorkel and I did notice the engine drove much better with the resonator on particularly when moving off from stopped.
  4. I decided to plumb the tube in a direct straight line from the snorkel to minimise pressure loss from wiggly tubes. In order to do this I had to relocate my resonator to the hole where the origonal air box intake was.
  5. Find a piece of tube to use for connecting the flexi hose to the air box.
  6. Mark where you will cut a hole in the air box. I marked all around where I wanted the hole to be with some bits of tape.

Step 8: Cut New Hole in Air Box

  1. Buy/find some tube that is the right size to fit snugly into the flexi hose. I bought a length of 75mm plumbing PVC tube from my local hardware store.
  2. Cut the hole in the air box in stages, regularly offer up the tube to the hole to work out how to adjust the cut. I used a jigsaw to cut the hole (drilling a hole to get it started) and I used a dremel to open up the hole to the right shape and size.
  3. I had to raise up the airbox with some extra long bolts to avoid the tube getting too close to the air filter. If you're doing this of course make sure the bonnet can close without touching the airbox.

Step 9: Glue New Tube Into Air Box

  1. Rough up all surfaces will some corse sand paper 40 or 60 grit.
  2. Remove all dust and throughly clean all gluing faces using an evaporative cleaner e.g. brake cleaner.
  3. I used a kneadable plastic bond glue which gives a really strong bond and sets like a hard plastic. I've used it before, it's really good stuff. It does start to cure in just a few minutes so I added the glue in little bits to prevent waste, pressing it right into the edge.
  4. I bought a plumbing flange piece that pushed onto the resonator really nicely. I used this to fix the resonator onto the hole where the intake used to enter the air box.
  5. I cut some scrap plastic into a disc and glued it over the hole of the resonator's origonal position.

Step 10: Sealing the Air Box

  1. Squeeze out a bead of silicone around the outside edge of your glue lines.
  2. Remove the rubber soft-mount gromits, clean them up, add silicone, then put them back.

These steps will make double sure that no water can enter the airbox.

Step 11: Final Assembly

The big theme in the final assembly is add silicone everywhere to make sure rain/river water can't get in anywhere, not even a drop.

  1. Apply silicone around each fender stud and the big fender hole (to prevent rain water from flowing through your drilled holes), then tighten up all studs/nuts. You'll likely need to remove the plastic wheel arch liner to get your hand in the fender in order to tighten up the nuts, often this is held in with little plastic clips that will pop off with careful prying of a flat head screw driver.
  2. Cut a length of the rubber U-channel edging trim and insert it onto the edge of the big hole. This is really useful to prevent road vibrations from causing the metal edge to cut through the flexi tube as you don't want water to get in through any holes!
  3. Attach the flexi tube to the snorkel tube, add silicone to make it water tight, tighten up the jubilee clip.
  4. Fix your air box back in place (mine had to be raised a little bit). Seal the flexi tube onto your air box tube with silicone and tighten the jubilee clip. Add some silicone to seal the airbox mounting bolts.
  5. Add silicone to any other joins in the air intake tubing for example the connection to the throttle body, air resonator connections. If you are confident in some joint's ability to seal without silicone then that's ok.

All done! Time to go off road to have fun crossing rivers and be smug knowing your car is breathing in cleaner less dusty air.

PS: If you do plan to cross deep rivers consider waterproofing your starter motor and extending your diff breathers.