GenVibe - Community for Pontiac Vibe Enthusiasts

I was just wondering if anyone has an idea as to how many HP the cold air part of a CAI actually adds. If you had identical air intake systems and used one with "engine air" that was warm and one with colder outside air, how much HP would the colder air intake produce due to the air temperature differance? Anyone have any ideas?Jim

Nothing scientific, but it would be a few horsepower for sure. Colder air is more dense, hence more air per cubic foot. Also, the less restrictive intake allows more air to be ingested into the motor. A CAI is one of the best mods period.

It would be good to see the actual dyno'd differences

TECNOBABBLE ALERT!!!Per a previous post of mine which I'm too lazy to look up, Physics (air density vs. temp.), says each 7 degree F. temperature reduction adds 1% power. In practice, cold air picks up more heat as it passes through the intake system than warm air, so the real number is about 1% for each 10 degree drop. To know exactly what you'll gain, you have to measure the temperature at the actual stock inlet point, which is near an opening in the radiator support. I need to re-check this in the hot weather, but last winter, using a calibrated thermocouple read out, the inlet air was only 8-10 degrees hotter than outside air. (If you had a short ram system picking up air deep inside the engine compartment, I'm sure it would be 30 degrees or more above ambient.)There are several additional potential sources for power increase in a "CAI" system:o Low restriction filter.o Larger lower restriction tube.o Fewer, smoother bends in the system.o System tuned as a "Helmholtz resonator" to pressure pulse-tune at selected RPM range.o Changed mass flow sensor readings affecting air/fuel ratio, because the sensor reads just a "sample" of air in the tube and calculates the total based on the known area of the stock system at the sensor location. ( This could account for the check engine lights some members experience, if the pipe area is so different that the computer reads the apparent lower flow as a sensor error.)>END ALERT