Air Intake Options








-Payam
not to beat a dead horse, but there’s likely a reason that the best AMG-only tuning shops simply use higher flow filters in the stock boxes.
The Best of Mercedes & AMG




not to beat a dead horse, but there’s likely a reason that the best AMG-only tuning shops simply use higher flow filters in the stock boxes.
My comment: I think what he's saying in the last sentence is emphasizing that pressure drop (along with IATs) is the real culprit you want to overcome with an intake system. And if you (over)design an air intake that is actually capable of flowing greater than what the motor/turbo can actually pull, there's no downside, and actually there's an upside, in that this increased flow capability translates to a decreased pressure drop on the intake side. And this eventually translates to maximizing airflow into the turbo and engine.
Here's a simple yet great explanation I found from another site as to why pressure drops are so important in intakes: https://www.hpacademy.com/technical-...ons-explained/
"When the piston descends in the cylinder, it creates a vacuum or low pressure area in the cylinder. When the intake valve opens, we now have a pressure differential between the vacuum in the cylinder and the atmospheric pressure outside. This pressure differential causes the air to flow into the cylinder to equalise this imbalance. The larger this pressure differential, the more inclined the air will be to flow into the cylinder, resulting in a better cylinder fill and the potential for more power. This is the exact principle that superchargers work on - They artificially increase the pressure differential forcing much more air to flow into the cylinder.
Now for an example lets take a GM LS1 5.7 litre V8, where each cylinder displaces 712 cc (5700cc / 8 cylinders). In the perfect world, each time the piston descends on the intake stroke, the cylinder will be filled with 712 cc of fresh air – a situation that would be known as 100% volumetric efficiency (VE). It’s the engine’s ability to fill its cylinders with fresh air during the intake stroke that defines the power potential of the engine.
While we have established that under standard conditions we have 101.3 kPa of air pressure to force the air into our engine, this is only partly true. See before the air gets a chance to make its way into the cylinder, it covers a pretty torturous path through the intake system. This includes the airbox, air filter, airflow meter, intake plumbing, and finally the throttle body. If we want to get pedantic, it also must flow through the intake manifold, the intake ports in the heads, and finally past the intake valve. Each step along this path is a potential source of restriction.
So what exactly do I mean by a restriction? Well while we have 101.3 kPa of atmospheric pressure to play with, this is not acting directly against the intake valve. It only exists at the entrance to our air box, and from this point anything that restricts the flow of air into the engine will result in a slight pressure drop. We may only be talking about pressure drops of 1-2 kPa, but by the time you introduce several such restrictions, we find that the air pressure actually available to act on the intake valve may be only 95 kPa or worse. Now our air is much less inclined to flow into the cylinder so our cylinder fill is reduced (represented by a reduction in VE), and the end result is a smaller bang and less power."




We've done this testing on my 800whp 335i when doing filter testing. We had a mesh screen on (Turbo guard) couldn't make more than 24 psi.
Pull the mesh screen and we were able to go up to 26 psi. Put our filter on, and we're able to boost more than 30+ psi. (Maxing out WGDC same tune on each run)
BTW, our filter is flat and has a great amount of surface area. Not your traditional cone filter

-Payam




https://youtu.be/Cn0D3d_78wo



