How to build a cold-air intake for your engine

HOW TO BUILD A COLD-AIR INTAKE FOR YOUR ENGINE

By Gavin Deriu

Background:

I’ve always loved cars... Everything about them really – cornering them, accelerating them, modifying them, looking at them, hearing them, comparing them, and understanding the physics of it all.

Cars don’t need to be fast to be fun, and one way to enjoy any car (even a slow one!) is to improve the sound it makes. And a cheap way to do this is to install a cold-air intake. It changes the way the air resonates when entering into the combustion engine, and it sounds mad.

STEP 1:

You’ll need to source some parts first. I did this operation to my car, a Mazda Mx-5, and the first things I needed were a K&N Typhoon tube and pod filter.

Here’s a link to similar products on the K&N company website: http://www.knfilters.com/kits.htm

NSW car defect laws require the end section to be enclosed in a box, which we’re going to make ourselves. So also buy some 2mm sheet metal from Bunning’s to be bent into shape. Grab some standard tools like screwdrivers, wrenches and pliers, and we’re ready!

STEP 2:

Take out your old air intake tubes and air filter box. Obviously this operation differs with each car, but it’ll usually be a case of removing screws and clamps. There’s also an air sensor that you have to unplug.

STEP 3:

Install the Typhoon tube and pod filter. You’ll have to loosen the clamps and then fasten them back onto the new tubes. This is what it should look like when installed, without the box having been built yet. Don’t forget to plug the air sensor back in!

STEP 4:

It’s time to start making a box to enclose this baby.

The science behind cold-air intakes is basically this: your engine gets hot, so underneath the bonnet is a lot of hot air. This is bad because hot air has less oxygen in it, and therefore doesn’t combust as well when it goes into your engine. So we enclose the air intake into a box which collects (cold) air from the front grille of the car and not (hot) air from under the bonnet. Cold air = more combustion = better sound!

STEP 5:

Use bits of cardboard to make mock-up walls of your box, and when you get the right size and bends, make the “real thing” by cutting up the sheet metal. It’s easy to cut. I actually used a pair of sharp scissors and it did the job just fine.

By this stage, your work area should be a complete mess of tools, cardboard, metal and swear words, just like it was for me!

STEP 6:

Use strips of strong rubber to surround the metal edges of your intake box. This will prevent rattling, and will help it to be as air-tight as possible once it’s in.

STEP 7:

Once the box is complete and you’ve fixed it into your car’s engine bay, slap on a K&N sticker (worth 1000 street-cred points).

STEP 8:

Time to clean up all the mess you’ve made. Another thing to do is to check you haven’t left any random tools sitting on top of your engine. This could really throw a spanner in the works (literally) when you turn your car on and start driving.

STEP 9:

Job well done! You deserve a cold drink and maybe a banana for energy. Wash all the oil and black stuff off your hands and go raid the kitchen.

STEP 10:

I hope you didn’t eat too much because there’s a small chance you’ll soil yourself in this final step. That’s right... It’s time to take your car for a drive and listen to the beautiful sound it now makes.