951gashog

My stock AFM hairspring tension was "re-adjusted" by previous owner. My understanding is that Bosch calibrates their outputs according to flow, by laser burning of the thick-film resistors on the sweep. This implies that the spring settings should be about the same tensions on these, if the calibration is done by the laser burning, rather than spring tension adjustment.
Does anyone have pics of their spring settings?? I can count teeth from where the clip hits the gear, to where the spring goes into the gear, and get it back into the ballpark of where it supposed to be.
Thanks..

stv951

Any ideas on this ?
Has anyone adjusted theirs ?

robmeister951

I just discovered (after taking AFM apart to check the resistor strip) that someone has adjusted the preload.
There is a white mark where the setting was, and now it's about two inches further clockwise.

Anyone done anything with theirs and can report on what it actually does to the behaviour? or why someone would do this in the first place?

Rob

Ski

This was common, if you installed larger injectors in a car that had upgraded the turbo but not MAF. The theory behind it (vision) was that you would slow down the barn door from opening so quickly, not making the car "black" rich, thus aiding in spool up time and a better A/F ratio while getting on boost. You were always supposed to make a mark of the OEM spot where it was set.

Also, most people have tried to bend the sweeper arm, slightly in, then out again near the end, thus putting the points on a new contact patch, as the other track wears, so does the resistance it puts out.