I'm wondering if someone has some hard data or would be willing to test this. It would be a really good test/dyno session. What I'm wondering is does a cold air intake on the evo x REALLY bring cooler air into the motor? With that said here it goes. I'll give 3 intake styles.


1. Stock OEM intake system

2. Open element short ram intake system

3. Cold air intake system


Now there would have to be an air temp sensor mounted just prior to the throttle body in the charge tube to collect data, but simply air intake temperature. I would want to see this test done with a stock intercooler and then swap in a nice FMIC upgrade. Monitoring the air temps with each intake. Basically 6 tests. What I'm getting at, is the intercooler the main controller of the intake charge temperature or does your intake system actually have some effect too. Yes I know it does depend on the turbo, boost pressure and it's efficiency ect. Now this test has nothing to do with horsepower or which intake makes more power. It would simply be air intake temperature on an intercooled turbocharged car and if the source of the air intake from the turbo inlet has anything to do with this. I can see how the temps "might" vary using the stock intercooler. But with a nice big upgraded FMIC I would hope all the temps would be at ambient or very close to?

 

Here are my thoughts on the subject.

A turbo is ok sucking hot air, as long as it is not at max flow. Basically, it just has to spin a bit faster to flow the same amount of air, as it would be sucking warmer less dense air.

Once the turbo is nearing the point where it needs to flow as much air as possible, say 6000 RPM, your car is going plenty fast enough to have cold air under the hood.

None of your tests would work on a dyno, because cars are run with fans blowing at a constant speed at the front of the car and the hood is up.

 

I would say that a CAI does indeed probably produce best gain due to a denser charge of air at a certain speed etc... but the gains are probably in the single digits. But if you are looking for every last possible HP out of the car. Then a CAI would be best, along with porting everything and running smooth piping with minimal bends and welds etc...

 

The problem with CAI is their lengths. You will lose some top end because of the extra vacuum needed to draw air through it.

This is one of my favorite tests. Take a 5' length of garden hose and breath through it. Then take a 10' chunk of hose and try to breath through that. It gets harder.

So, in my head, a Short Ram intake will have very similar torque and better top end. CAI will have slightly better bottom end and worse top end.

Again, the turbo will make up for the less dense hot air. These are NOT n/a cars, so all the rules that apply to them get thrown out the window because we have a massive air pump stuck in the intake path.

 

I did a minitest similar to this last year, just using EvoScan to log the OEM sensor outputs, and a remote digital thermometer to monitor the air temp. I just took my kitchen thermometer that had a sensor outside, put it in the car with the sensor under the hood, and called it a day

Where exactly are the IAT and MAT sensor? IAT is in the MAF, and MAT is in the throttle body, right?

Anyway, with the stock airbox, on a mid to high 70's day, the under-hood temps were around 105f, with IAT around 100, and MAT around 105f. My conclusion was that the box-style intake didn't do anything to supply colder air, as the air was already just about as hot as the under-hood air by the time it passed the IAT sensor (MAF?)

I have an AMS short intake now. I could retest some time, but being its a different day, different tune, etc, it wouldn't be very scientific. And I'm pretty sure we all can guess what the result would be

 

I just took a bag of sand and held the pedal to the wood, poured it in the intake, and the car seems to run alot better now. I think It might have opened the whole system up. Maybe try this mod OP