pudrpz

was wondering if anybody got it to work because im having problems with it.

thanks

Outsane

Interested to hear some results...

I have a SAFC sitting in the kitchen

gennro

I'm not sure why you would want to even waste your money on a SAFC since you can adjust the airflow meter by drilling out the plug for the airflow bypass screw and adjust the air fuel mixture that way.

Outsane

I thought that was idle air mixture.. and has no effect while not at idle..

94sasyota

interesting i would also like to know if this would work

gennro

Adjusting the screw will affect air sensed by the air flow sensor at all RPMs. Screwing the screw out leans out the mixture and screwing it in richins the mixture.

Crude drawing below

Outsane

i was thinking about the mixture screw on a carb.. ha ha...

fail

abecedarian

Just wanted to add that it's true the screw affects airflow through the meter but it only influences the mixture with any significance when at idle. At wide-open throttle, the volume of air flow is much higher than at idle (and the fuel map is different as well) so it has an even less effect at that throttle position. At part-throttle, the VAFM is only a reference and the O2 sensor feedback to the ECU trims the final mixture.

To demonstrate the air flow situation (note: the following is not 100% accurate since air is compressible and water is not, and the water source is pressurized, but is adaquate for illustrative purposes)....

Imagine you have a fire hose and a garden hose (yes, it's rated for that pressure ) both connected to a fire hydrant. Both hoses are in parallel, feeding a spray nozzle and there is a valve at the end of the garden hose, before the nozzle: both hoses have the same pressure supplying them but the garden hose is flow restricted by the valve before it gets to the spray nozzle. The spray nozzle itself is mostly closed except for a small trickle (analagous to throttle closed where some air can pass by for idle).
Now assume the ratio between water moving through the fire hose and garden hose is say 25:1 (after we factor the difference in cross-section between the hoses and the valve on the garden hose ) meaning most of the water is coming from through the fire hose, but the garden hose is supplying some too. Now open the valve on the water hose a bit and the ratio goes down to 20:1 (more water from the garden hose). What happens if we open the spray nozzle at the end? Well, the garden hose is mostly maxed out on flow already (due to the valve) so the fire hose delivers exceedingly more water as the spray nozzle is opened more and more, causing the ratio between fire and garden hose to go back to 25:1, then 30:1... 50:1... 100:1... 500:1.
The ratio between flow in the fire hose and garden hose is analogous to the signal the VAFM sends to the ECU on our engine since as the engine requires more air, the additional air travels through the vane (the fire hose in the example) and not around the vane (the garden hose) therefore as the flow through the meter increases there is not a proportional increase in flow through the adjusting screw lessening the effect of the bypass on fuel mixture as air flow increases.

Duffdog

were you ever able to get the safc to work with the 22re?