George and Bruno: question on the MAF curve

[Jeff N.]

A week or so ago we were bouncing around MAF curves and George posted one that was from testing at Pro-M.

See here (http://www.bimmer.info/forum/showthread.php?postid=30684#poststop) for the orignal conversation.

Couple questions for Bruno and George:

1 - this curve was based on flow testing the stock vane AFM and then developing the same flow/voltage outputs via the MAF curve, correct?

2 - was this curve done with a stock airbox or a cone filter?

3 - any idea on the "health" or age of the AFM that was benchmarked? Pretty new or a higher mileage unit?

Any other details that come to mind on the testing?

Basically, I'm getting ready to run some tune tests and plan to "lock in" the MAF during these tests. I'd like it to be as close as possible to the stock AFM and don't plan to change the settings during the tests.

Would like to understand how close this curve might mirror the stock AFM setup.

TIA!

Jeff

[George M]

Bruno can confirm but answers are:
1. Correct...stock AFM was attached to a flow machine and measured for flow versus voltage. The controller for the new MAF was then calibrated based upon this voltage map versus flow.

2. Don't believe there was any restriction to the AFM installed to the flow machine.
Reason is...not relevant as the flap on a conventional AFM deflects given a certain volumetric flowrate through the AFM body. A cone or std. air box filter would simply reduce maximum flowrate into the AFM not inducing full flap angle for max flow and therefore would not affect actual calibration of flap position versus voltage to the DME.

3. Baseline AFM was Bruno's original stock 1989 AFM and likely had original factory calibration.

HTH's Jeff,
George

[632 Regal]

talk about jibberish... wow!

[Jeff N.]

thx george!