Petza914

Has been discussed many times. No way to simulate car in motion on a dyno, no issue with CAIs as long as the filters are properly maintained and not over oiled. I've actually had silicon levels drop after installing a K&N vs stock paper filter.

flat6---

I am sorry to ask, I just don't understand enough. How do you explain the loss of HP on the dyno?,

So dynos information doesn't mean anything then?, what's the point then?

Petza914

Intake air temp is higher because no matter how many fans you put on a stationary car you can't simulate the volume of fresh air going into the intake and engine compartment, so the air going in is less dense because it is hotter as it's being sucked in from the warm engine bay. 2nd, if that's the name vidwo everyone links to (I didn't watch it again) they never forced a reset and relearn of the DME between the runs, so the car computer isn't even using the increase airflow available. Without a battery disconnect, reset, and then some drive time to relearn it will eventually figure it out, but not in just a few dyno runs.

Graufuchs

Put a dyno inside a wind tunnel, match the speed of air to speedometer...that will present more accurate results. (still will not be 100% accurate due to mechanics of dyno/sensitivity of sensors)

Every car has different low air pressure and high pressure areas. Air inlet scoops/spoilers/cowl areas/front bumper areas see the highest pressure when moving at speed. Low pressure areas such as inside the cabin and inside the frunk see much lower air pressures when moving at speed.

A neat example of this is driving 80mph and cracking the window, the differences in pressure create a cracking or whip like noise when the air inside the cabin (lower pressure) begins to match the air flowing outside the cabin (higher pressure).

Now you have an intake system that relies heavily on drawing air from a high pressure area, on a dyno you are not correctly replicating that area of high pressure for the intake to draw from.

Utilizing a dyno is helpful with a before and after when you are significantly changing components, with an intake system (depending on how poor/muffled the factory system is) you are typically looking at gains of 1-3% if that, so you are looking at a degree of error that can easily be affected by ambient/external factors such as air flow, air temperature etc.

On top of all of this you are looking for an adaptation period from the ECU to adjust in small increments to take advantage of said components. These adaptation periods vary from ECU (brand/programming) to ECU, these adaptation parameters also have limitations. Once these limitations are met, a new calibration (tuning) is required.