Cold air inlet

[Steeveedee]

If one takes the ambient air in without disrupting the stock inlet one can (usually) see a benefit. I had an '05 Toyota Corolla that I added a cold air intake to. It took air in through the hole where a driving light would be. The original inlet for the duct to the filter box was between the battery and the radiator. Kind of a dead space, and possibly the hottest place under the hood. I ran 2" ABS with a "Y" pipe that takes 3 inputs and has one output, sort of like a "scoop". The stock setup was in place, but cooler air could push out of there when the ram air effect overcame its input. There is a circular part of the duct to the air filter box that was accessible from the bottom; that's where I fed the cold air in. I gained about 1% in mileage, and it cost me about $13 in parts. 1% doesn't look like a lot, but I put 220k+ miles on it. That's 2.2k miles less fuel; at $3 a gallon and 35 MPG, that's 63 gallons, for a savings of $189. It did have a bit better performance, especially on really hot days. Nothing to write home about, though.

Buick had a set-up in '68 that was OTC at the dealership. It fed in from a hole in the firewall into the back of the air cleaner, so it didn't block the snorkel. It was verified to give ~ .1 second reduction in 1/4 mile ET by several users.

I wouldn't mind doing that on my truck, except for the secondary roar. It would be louder than the exhaust!