xr4tic

Do you really think they would put a screen in there to induce turbulence, causing a poor idle, bad readings, and messing up emissions?

Plus, if it was possible to remove it and not cause problems, then they would have done that, and saved a few bucks in the process.

Think man, think!

As for the resistance issue, go measure the inlet area of the turbo, then compare it to the inlet area of the MAF, and you'll see where the real restriction lies.

DarinS4Turbo

It's the same reason why K&Ns gain power on most cars, but do nothing on this car. Different car = different results.

Audiboy

reliability and performance disagree sometimes

Audiboy

good information you provided there

I'm guilty of no screens too because I did my own testing using MAF voltage. It's all about efficiency.

DarinS4Turbo

Saying that changing one component of the system on one engine and intake configuration, will have the same impact as changing that component on another engine and intake configuration, is invalid. Besides, the MAF pictured is NOT the same as the Hitachi unit on my 2001.

DarinS4Turbo

restriction, which is related to the physical design the MAF and is also dependent on the entire intake tract. All I know is my airbox, intake tract, and MAF on my 2001 are not physically the same as those pictured for the car the testing was done on. I tested it back to back with and without screen and saw no change in MAF measurement. You make an invalid argument that it might not be 'reflected' in the MAF measurment, because there is really just less 'loss' in the mass air due to cooler intake temps post turbo. If you don't understand the concept of 'mass in = mass out' , maybe you should read up in a physics book about the 'conservation of mass' principle.

Audiboy

you have m, so you derive n. Then you can see what effect Temp has on volume or pressure (depending what the turbo will try to keep constant)

So, no argument about mass in = mass out, but mass without temp means nothing to the ECU <ul><li><a href="https://forums.audiworld.com/s4/msgs/788217.phtml">it's all about efficiency </a></li></ul>

DarinS4Turbo

I'm just saying what it adds is not anything significant or perceptible, based on testing with my car (which I've explained above is not the same physical configuration as the car used in this testing.) It's just like high flow air filters... we replace the stock filter with something that flows better, yet we see no improvement, because what was already in place was adequate for the given application. Yet in a different application changing air filters (or removing the screen) may show a perceptible improvment.

DarinS4Turbo

This causes more mass of air to enter the engine, but all of that increased mass had to pass through the MAF (since that's the only place it is introduced in the system).

DarinS4Turbo

flow, and I saw none. I've never disputed any of the accepted theories of flow restriction, pressure ratio, and turbo efficiency, I'm just saying in my testing these things were not affected by removing the MAF screen to any perceptible degree.