GenVibe - Community for Pontiac Vibe Enthusiasts

Hi again

I am wondering if a CAI is going to be worth the bother.

I am using Torque (an Android app) with an eBay OBD bluetooth dongle to monitor things under the hood. I have yet to perform a calibration comparison, but my "intake air temperature" and "outside air temperature" are running at a 3-5 degree delta at highway speeds. This is with the factory intake on an 03 GT.

Due to heat absorption by the engine compartment intake components, I am wondering how much of a difference can be seen with one of the better cold air intake systems.

Many of the cheap ones offered on eBay are actually taking the warmer air from the engine compartment, which would most likely be much worse than what the factory provides.

Has anyone here taken before and after temperature measurements to determine the effectiveness of any given CAI system?

I have the Injen CAI on my car and have an ultraguage. I'll have to see if I can pull an intake air temp measurement for you.

My homemade CAI uses the stock air filter and keeps the intake temp to 1 degree over ambient when moving over 20mph.
This old post unfortunately has lost the graphs charted from OBD data:

http://www.toyotanation.com/forum/132-9 ... style.html

Any time the car is moving, the engine bay will be quite cool. Think about what's in front of the air filter: just the headlight and battery, no heat there really. The gap under the headlight and under the hood will be giving your intake lots of air.

lannvouivre wrote:Think about what's in front of the air filter: just the headlight and battery, no heat there really. The gap under the headlight and under the hood will be giving your intake lots of air.

On my Matrix the stock intake gets air that has passed through the radiator. Is it different on the Vibe?
I have to search for my old graphs, but they show the intake air substantially cooler with my mod.

Well, this morning I was able to do a "calibration." I turned on the ignition, but didn't start the engine. I then waited until all the sensors had a read.

Results:
Dash outside air: 74
OBD intake air: 77
Coolant temp: 77.8

So, my OBD temps are about 3-4 degrees higher than my dash outside air temp, when they are all at the same temperature (overnight soak, no sun, etc.).

That means that my highway-speed intake air is within 2 degrees F of my outside air.

I think I'll stick with my stock intake, especially since adding a CAI would bump me up a class at autocross.

Of course, when stuck in traffic, the intake air does get significantly higher temperatures than the outside.