The benefits that a traditional cold air intake has on power with K series engines have been verified over and over, yet many circuit-raced dc5's choose airboxes instead. Why?


Using a traditional cold air intake gains lots of power, but mid range can show less gains and increased lag in throttle response. This is because the filter is mounted so far from the throttle. When the throttle opens, negative pressure momentarily occurs between the filter and the throttle until air begins to flow through the filter and pressure equalizes.


Locating the filter as close as possible to the throttle would minimize this effect. To have the filter close to the throttle but still have control over air temp, an airbox design is the only option. Given that the design would be based on an airbox, the following traits would be prioritized:


-minimal throttle-filter distance
-minimal heat absorption to the box
-cold-air feed/snorkel




Spoon covers the factory airbox in insulation and runs a short section of dryer duct through an opening under the hood.













Here is a way to achieve a similar intake for $20:
You need to relocate the battery for this to work


Parts needed:


$6 -x2 3" 90* PVC elbows
$5-17" 3" PVC tube
$10-2x Rolls of foam/foil insulation tape
-zipties
-dremel/sanding tool






Step One:


Do the hondata airbox mod
http://www.hondata.com/techkseriesairboxmod.html


The tidier you make it, the less turbulent the air, and the more the air slows down when it enters the box. Less turbulent=more power. Removing the chamber that feeds the breather would also add to this effect, and could be done by using a separate filter on the breather tube and plugging the existing hole on the airbox.










Step Two:
Cover the airbox in insulating tape. Using glue to in some places might be wise. Look for scratches on the box that were made during installation and removal. You might avoid putting tape on those spots.













Step Three:
Cut the stock rubber snorkel at the last rib on the flexible section. Stretch it around the end of a 90* PVC elbow. The fit is very tight so using a sanding bit on a dremel to make a ridge around the edge of the PVC elbow will probably be necessary. Secure it with a ziptie, but first make sure it's aimed in the right direction: towards the fender~ same spot as a CAI. Attach the 3" tubing and wrap it all in insulation.








Step Four:
Cut an opening in the fender as if you were installing a traditional CAI. Attach the second 90* PVC elbow so that it sticks into the same spot as a CAI would.







No dyno numbers but the butt tells me it's faster for sure.