SAFC Air flow % question
 

On my 87 turbo 2 mods on sig below....When i take the filter off the AFM and press the flapper slowly by hand i only see a max of 77.1% Is there something funky going on with my AFM? Im pretty much maxing out my AFM when im boosting only 7.5psi with up to 72.7% air flow reading...Now if it is my afm are the non turbo meters the same? Or do I have to find another turbo afm....Need some input on this thanks...

sounds like whoever calibrated the AFM to the safc didn't do it properly, I believe you need to recalibrate and retune my friend

question though, what made you just decide to pull it apart? not running right or just curious?

Yes, that is what happens.

Turn your ignition on....take the filter off and push the flapper open all the way.

See what percentage it goes to.

No. That's all you'll ever see on that SAFC and afm combination. Another afm in it's place might give a different figure.

My observations using three turbo afm showed only the one that showed approx .300 vdc when fully open would display 100 percent. The other two afm had a voltage of say .350 fully open and showed percentage ranges in the 80's percentage or so.

I think we've also decided that it makes no difference whether 100 perecent or 86 percent if the flap is indeed wide open. At least I've settled on that idea.

So here's what you do. Turn the key ON. Look at the SAFCA in percentage with the flap fully aft. Now flip the SAFC to SENSOR CHECK and see what Afl reads in volts. I'm betting it reads more than .300 vdc. Probably close to .320 vdc.

And as a side note, I don't trust the accuracy of the voltage readings of the SAFC. I compared them to a Fluke meter and they are off. Fluke....good. SAFC....not so good.

Well i installed the SAFC myself and i put in the right settings for my year...So I dunno if there is such a thing as recalibrating the AFM to SAFC but maybe i mis read the manual??? Car runs fine no hesistation other than I was curious on this AFL reading deal....

And how high does it actually show when you're at WOT, full boost, max RPM?

Honestly, I don't think it matters enough to worry about. And regardless of what the actual voltages are, what the SAFC sees is what it tunes from.

-=Russ=-

Like the post(s) above said. Turn the key to ON. Shove the vane in the afm all the way AFT. Look at the percentage on the SAFC. What you see, is what you get. No more to be had. There is NO learning curve/calibration/fix.

Then turn the SAFC to sensor check and look at the voltage shown for Afl. I'd wager yours reads in the 0.350 vdc range.

If your still in doubt, take the cover off the afm and loosen the allen bolt and move the wiper on the carbon track til it is at the end of the track and observe the percentage on the SAFC. Five'll get you ten that the percentage isn't any different than what you've been seeing all along.