If that is without boost controller installed, something is screwy. I assume you have a boost guage installed?

Also, you have definitely gone a lot more lean than the Buschur settings. Do you still see carbon residue on the exhaust tip with those settings? That much boost and that lean will likely melt/break something soon, unless your motor is a true factory freak.

 

Sounds about right.

The S-AFC fools the engine into adding more fuel by altering the airflow signal to show less air than it is really getting. So the ECU (open or closed mode) will allow more boost because it thinks it's not getting enough to match up with its maps. The additional air will drive the FPR (Fuel Pressure Regulator) to deliver more fuel.

A boost controller should be your next mod.

 

netmand, he is pulling fuel, not adding it. Your statement regards the S-AFC is contradictory. Less airflow means less fuel for proper a/f ratio. So the ECU should allow less boost if it sees lower fuel... but its moot anyways, as the ECU is not going to raise boost due to an S-AFC. Ask the couple hundred people who have one installed if they suddenly had a boost spike. I know I didn't see any boost increase from the S-AFC.

 

I'm missing something then. The S-AFC is controlling fuel via signal adjustments to your air pressure signal. Take a look at your hook ups: air pressure, RPM, Throttle, that's it. So if it's taking fuel away it would need to alter the air pressure signal to a lower one, which lowers fuel but also raises boost, because the stock boost solenoid is controlled by the ECU too (and letting more boost because the ECU sees a lower air pressure signal from the S-AFC).

It's proof that the S-AFC is indeed working as designed. It has raised boost to lean out the mixture, which corresponds to his settings of pulling fuel.

I maintain that he needs to put in a boost controller to rememdy this. What do you think?