I've been considering investing in an intake for my car. I've considered options of an aftermarket intake like Comptech or K&N as well as a snorkel. All these options are supposed to bring cooler air into the motor, improving performance (even if that improvement is minimal). This got me thinking, exactly how hot is the air the engine is sucking in with the stock airbox.

I decided to do an experiment. I put the outdoor piece of my indoor/outdoor digital thermometer inside the airbox and kept the indoor section (which reports both temperatures) inside the car. I took 4 different trips, evaluating temperatures. The following are my findings.

Trip 1:
Conditions: Car is cool at start, 15 minute drive, speeds ranging from 0 to 60 mph, 1/3 of the time spent accelerating/decelerating from 0-60 and 60-0, 1/3 spent at 60, and 1/3 sitting at traffic lights.
Temperature: In cabin temperature at the end of the drive (and you northerners are going to hate me) was 104.4 degrees (all drives are top down, no heat or air). Inside airbox temperature is 103.5, surprisingly lower than in the car!

Trip 2:
Conditions: 3 hours after trip 1, I would imagine the car is cool for the most part, possibly holding some heat from trip 1. Similar speeds and conditions to trip 1.
Temperature: Upon getting in the car temperature is 108 in cabin (top still up at this point) and 107 in the airbox. After a 20 minute drive temperatures are 87.9 in the cabin and 103.2 inside the airbox (it has actually cooled 4 degrees after a 20 minute drive).

Trip 3:
Conditions: 10 minutes after trip 2, car is still warm from trip 2. 15 minute drive, same driving conditions as first 2 trips.
Temperature: 108.3 inside the airbox. 84.3 in the cabin.

Trip 4:
Conditions: 5 hours after trip 3, car is cool. 20 minutes driving, 5 minutes sitting at Taco Bell drive through, 5 minutes driving. Late at night, much less traffic and less stopped time (except at the drivethrough).
Temperature: In cabin temperature 74.9 degrees. Airbox temperature 107.2.

Conclusions:
Even in very warm weather the inside airbox temperature stayed surprisingly cool. I had little expectations going into the experiment, but would not have been surprised to see temperatures exceeding 150. Being that airbox temperature never eclipsed 110 degrees, I see little benefit that could be obtained by a snorkel. I would also assume that any benefit obtained from a cold air intake would, for the most part, be from a higher flowing air filter not from actual cold air. Note: I assume that the motor reached operating temperature in each of my drives. I believe this would be accurate after 15 minutes, but what do I know?

Disclaimer:
I realize this experiment provides nowhere near enough statistical control, variable isolation, or sample collection to ascertain a reasonable conclusion. I do however feel that I quenched my curiosity as to the stock airbox intake temperature and will now commence looking for a high flow air filter rather than a cold air intake or snorkel. If you disagree with my findings or methods I urge you to please recreate the experiment in your own environment and post your findings.

 

You should do the same experiment, but with some more aggressive driving (redlining/decelerating quickly) as this is when performance is really needed, and is the largest reason why people will buy aftermarket intakes.

 

thanks for the info , but i was hoping for temps if you track your car and such
thanks anyways...nice to see that the stock airbox is well engineered

 

Good to know!

Anyone can do the same with J's Racing CAI!

 

Here are my experiments from years ago, with all sorts of parameters, spanning a whole summer:
https://www.s2ki.com/forums/index.php?showtopic=19725
https://www.s2ki.com/forums/index.php?showt...underhood+temps

With AEM:
https://www.s2ki.com/forums/index.php?showt...mp+measurements