rberry951

Here's a good reference...

http://frwilk.com/944dme/afm.htm

Regards,
Russell

PuttingThePoorBackInPorsche

If the barn door is fully open, producing "max flow" signal to the DME this could be a problem especially if the boost is jacked up. Think lean conditions.

hally

Once the AFM signal is maxed out you are relying on the WOT fuel map settings to determine your a/f ratio. Thats why aftermarket chips are designated for a specific boost level, they are setup for a specific flow.

Should add that you can get more fuel out of an AFM setup with a piggyback, as there is room above where the AFM signal maxes out. The highest AFM voltage readings i remember anyone posting is around 4.5v (i got 4.3 running a k26/8 at 16psi), so with the piggyback you can utilise the remaining 0.5v to dial in additional fuel.

Andial951

Are you speculating or stating fact?

Tom M'Guinn

[QUOTE=hally]Once the AFM signal is maxed out you are relying on the WOT fuel map settings to determine your a/f ratio. Thats why aftermarket chips are designated for a specific boost level, they are setup for a specific flow.

QUOTE]

Put another way, once the barn door is open all the way, the DME will supply a specific amount of fuel. All other things equal, that amount of fuel will remain the same even if you triple the boost, since the extra boost can't open the door any further. The DME just sees an open barn door in both cases.

Mercedesben

I thought the chips, larger injectors and 3bar fpr would prevent a lean situation even with an afm since the chips control the fuel ratio.