MAF testing results, screen removal and S-Flow:
07-10-2004, 08:48 PM
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MAF testing results, screen removal and S-Flow:
I tried a few things with the MAF in order to maintain accurate flow as well as remove the restriction of the screen.
First I hooked up a makeshift, uncalibrated manometer using clear plastic tubing in an M shape taped to my windshield filled with the V of the M filled with cranberry juice... too lazy to get some food dye ;/ Anyhow, hooking my ghetto manometer on either end of the MAF illustrated that there was a measureable pressure differential across the MAF during WOT (I did this while not moving, so it was just a rev-rev thing and marked the high point of the movement of the liquid cran-matter, so it's probably a greater delta during WOT while in motion).
Now I drove around (without that silly thing taped to my car) and logged a bit. Peak was around 279 g/s. I then took out the MAF and removed the screens. Peak went up to 284 g/s and it was a smooth and gradual increase across the board. No indication of any loss of laminar flow.
Why is this? Well, I'm guessing my S-Flow combined with the nice bell-mouthed ITG filter straightened out the flow well before the MAF.
Final testing showed an inch less motion in the ghetto-cran-ometer, which seems to back-up findings with the VAG tool.
I was going to try using large fins and such, not unlike the Delphi units in LS1 powered GM vehicles, but it seems it's not needed with my setup.
Lesson learned: The S-FLow and ITG filter smooth out the intake flow to the point that the MAF screens are not required to provide the laminar flow for accurate MAF readings. Next I'm going to try other filters, K&N and a longer variant of the ITG, not unlike the one used in currently sold S-Flows and see if any difference can be measured.
First I hooked up a makeshift, uncalibrated manometer using clear plastic tubing in an M shape taped to my windshield filled with the V of the M filled with cranberry juice... too lazy to get some food dye ;/ Anyhow, hooking my ghetto manometer on either end of the MAF illustrated that there was a measureable pressure differential across the MAF during WOT (I did this while not moving, so it was just a rev-rev thing and marked the high point of the movement of the liquid cran-matter, so it's probably a greater delta during WOT while in motion).
Now I drove around (without that silly thing taped to my car) and logged a bit. Peak was around 279 g/s. I then took out the MAF and removed the screens. Peak went up to 284 g/s and it was a smooth and gradual increase across the board. No indication of any loss of laminar flow.
Why is this? Well, I'm guessing my S-Flow combined with the nice bell-mouthed ITG filter straightened out the flow well before the MAF.
Final testing showed an inch less motion in the ghetto-cran-ometer, which seems to back-up findings with the VAG tool.
I was going to try using large fins and such, not unlike the Delphi units in LS1 powered GM vehicles, but it seems it's not needed with my setup.
Lesson learned: The S-FLow and ITG filter smooth out the intake flow to the point that the MAF screens are not required to provide the laminar flow for accurate MAF readings. Next I'm going to try other filters, K&N and a longer variant of the ITG, not unlike the one used in currently sold S-Flows and see if any difference can be measured.
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