Autoblog Project Garage: Cold-air intake, Part II
With some minor disassembly performed in Part I in anticipation of a new cold air intake, we also performed a few modifications that will be explained further in some later posts. Now that the car and components are ready for installation, let's dive under the hood to finish up this project.
Since the scoop will poke through the air dam, we decided to remove the latter to simplify the task of opening a hole. A few spins of a nutrunner are all it takes to remove the handful of sheet metal screws holding the air dam in place.
A template is provided to establish a properly-sized opening.
With the outline of the hole drawn in paint marker, a sharp knife can be used to slice the soft plastic material. Watch your fingers, or else those precious digits will end up resembling those of the Autoblog Project Garage staff.
A few test-fits on the bench and a bit of trimming leave the opening just large enough for the mouth of the scoop to pass.
A pair of pilot holes are drilled for the sheet metal screws that will be used to attach the scoop to the filter canister, but the screws are not yet installed.
The canister is then lowered in from topside, snaked between the sway bar and the lower radiator core support, and hung from the bar with the supplied hardware.
Due to our non-stock front sway bar (it's actually the 32mm unit from a early '80s WS6 Trans Am), this part took the better part of an hour. Taking ten minutes to pull the fans probably would have brought the whole task down to fifteen minutes or so, but that's not really the way we work.
A clamp is then placed on the canister in anticipation of installing a filter.
The included S&B filter is pre-oiled, so all we have to do is pull off the wrapper.
The filter is clamped directly to the mass airflow sensor, then receives a rubber coupler.
The coupler affixes the filter/MAF assembly to the elbow, which is then attached to the throttle body via a flexible boot.
The filter assembly is dropped into the canister (those that live in particularly dirty areas may want to consider pulling some pantyhose over the filter before installation).
The boot and elbow are then secured to the throttle body.
As a final step, we have to secure the wiring and vacuum hoses. We start with the vent tube for the distributor...
... continue on to the intake air temperature sensor...
... and finally we plug in the MAF extension harness.
The last step is to re-install the air dam, and attach the scoop to the filter canister
The completed cold air intake assembly looks something like this from the underside...
... a bit like this from inside the engine compartment...
... and a lot like this from up top. Notice the way that camera flash really accentuates all the dead bugs that we failed to clean off before parking the car last fall.
Obviously, such a system is highly susceptible to water and debris ingestion, as well as being vulnerable to contact with curbs and other low obstructions. Drive accordingly, and if this any of this presents a problem, thinking about selecting a different system.
As for results, we've yet to roll the car onto the dyno, but a few quick blasts down the street with the data logging software showed a dramatic decrease in intake air temperatures. That can increase power in two ways - by increasing the density of the incoming charge, and by reducing the propensity for detonation and thereby allowing a bit more ignition advance. The first comes automatically, while the second may require a bit of PCM tuning to fully utilize.