Fitting a Cold Air Intake (DIY Kit & Pre-packaged)

Fitting a Cold Air Intake

Installing a cold air intake on your import or domestic vehicle should be one of the first steps you take for increasing your cars performance.  Along with a good high flow cat-back exhaust and intake will help bring cooler air into your engine thus increasing horsepower. The great thing about intakes is that they are not extremely expensive.  If you do not have hundreds of dollars to by a name brand aftermarket intake then you can also build you own by obtaining the needed parts from home-hardware suppiers (pipes, clamps, hoses) and a cone filter from your local auto parts dealer.

In general a home made cold air intake and aftermarket cold air intake will both complete the same job as effective as each other.  The main difference being the aftermarket intake might add a nicer look to your engine bay and possibly some value to your car as well.  The choice is yours!  

Our install is into a CRX DelSol, but the methods are the same reguardless of who built the vehicle or the model ! So are you still in ? Lets get into it.

 Assembled and ready

What you'll need:

1)  Socket wrench and metric socket set with extension bars
2)  Phillips head screwdrivers
3)  Electric drill and bit set
4)  Clean, damp cloth
5)  Aftermarket Cold Air Intake System

If you're building a custom intake as well:

1)  Duct Tape
2)  Phillips head screwdrivers
3)  Electric drill and bit set
4)  K&N or equivalent cone air filter
5)  3 1/2" Diameter Dryer Ducting Hose
6)  Assorted PVC Elbows for Joints
7)  Dryer Hose Clamps and PVC Glue
8)  Air Scoop for mount under front bumper

Step 1 - Open hood and remove front bumper

Open the hood and remove the negative battery terminal from the battery, but if you have a stock stereo, remember to note the radio code!  Over the top edge of the bumper (covered by the hood) you will see several black, flat Phillips type screws with rubber gaskets.  Remove those.  There will be a black metal retainer that comes off after all are removed.

Open the hood and remove the front bumper

With that done you will need to get under the car.  There will be 10mm bolts (2) that need to be removed with the socket wrench.

Under guard protector

Here is the interesting part.  There are hidden Philips head screws (2) connecting the sides of the bumper to the front quarter panels (one on each side).  Remove the front part of the plastic wheel arch cover (3 screws).  Reach inside the quarter panel to where the screw is, and using a small Philips head screwdriver, remove the screw.  Be careful at this point and ensure that the bumper is supported so it does not hit the ground and get damaged.

Everything removed

This should take you around 20-30 minutes to complete. On to step 2 !

Step 2 - Removal of stock intake system

The stock intake is basically composed of four parts.  The first is the intake head, which is from where the system draws air.  The second is the resonator box, then the filter housing, and finally the intake duct.

Factory intake system

Here the components of the stock intake are shown in the car.

Lets remove all this stuff

The first step is to take out the intake head.  The filter housing and intake duct are then ready for removal.  The intake duct is attached to the throttle body by a single clamp.  Loosen the clamp with a small Philips head screw driver.  The filter housing is held in place with (3) 10mm bolts, located as shown in the photo.

Air box

After removing the bolts, the filter housing and intake duct are removed from the car.

Airbox out

The final step in removing the stock system is to remove the resonator box from the wheelwell area.  There are (3) 10mm bolts that hold the box in place, and which may not be obvious at first.  One is located under the car.  Due to the shape of the box, it is also difficult to remove from the wheelwell.  Pull down on the drivers side of the box first, as shown in the photo.

Remove the bottom section

This should take 10-15 minutes. Onwards to Step 3 !

Step 3 - Install Aftermarket Intake

The aftermarket system requires a little preparation before installation in the car.  First, a 0.5" hole is drilled in the blank protrusion on the upper intake duct.  The brass fitting is then carefully screwed in place, by hand as far as possible to make sure that it enters straight.  A 13mm wrench is used to tighten it, but avoid overtightening.  The purpose of the brass fitting is to allow the valve cover breather hose to route into the intake cleanly.

The smaller blue connector sleeve is then placed on the small end of the upper intake duct, and clamped securely using a hose clamp.  The mounting hardware assembly is attached to the threaded bushing on the underside of the upper duct, but not tightened to allow adjustment. 

Attach the upper intake duct to the throttle body using the connector sleeve.  Secure, but do not overtighten the second hose clamp.  Attach the other end of the mounting hardware to the car body, using the closest existing bolt hole from the stock filter housing.

Install the black trim piece around the resonator box inlet hole.  This prevents scraping of the lower intake duct during installation, and makes for better looks.

Slide the larger blue connecting sleeve onto the end of the upper intake duct.  Securely clamp the sleeve to the upper duct.  From inside the bumper area, pass the smaller end of the lower duct through the resonator box inlet hole in the bodywork.  Attach the lower duct to the upper duct, and tighten the clamp.


Attach the K&N cone filter to the end of the lower duct, and firmly secure with clamp.

Cone installed

Make sure all the components are aligned properly, and tighten the remaining clamps and mounting hardware bolts. 

Re-connect the negative battery terminal.  Turn power on to the car, and crank it up!! Ta-dah!!  The intake should make a distinct sucking sound at idle.
Again, 10-15 minutes for this stage. On to step 4 !

Step 4 - Install breather and coolant hoses

Attach the breather hose to the brass bushing, and clamp in place.  Use additional lengths of hose to replace the coolant hose, since the stock metal tubing and lines will not be re-installed.
Completed in 5 minutes. Next Step !

Step 5 - Re-assemble bumper

Re-assemble the bumper, in the reverse order that it was disassembled. Time will be about 30 minutes.

Step 6 - Advertising

Attach a K&N decal, otherwise no one will know you have a cool aftermarket intake !

Depending on the vehicle, this modification will provide approximately 5-10 hp at the flywheel on a stock NA engine, more on a turbo

Stock IntakeAftermarket Intake

FACTORY            versus      Aftermarket