Just installed a AEM wideband A/F meter and I am getting 14 to 15 in normal driving and 11.5 to 12 WOT from 1 to 6 pounds of boost.

What is normal and what is optimal????

99 Mountaineer 5L w/Powerdyne blower

Thanks

 

What you're getting is about right, for a mild state of tune with a turbocharger.

Optimal can be determined by running the vehicle on a dyno, and adjusting the A/F for WOT up and down until you find your peak HP/Torque in the RPM range your truck might be running on the road.

Common mistake is to tune for an RPM range you'll rarely use. If you rarely, if ever hit 5500 RPM, don't bother optimizing that RPM range, tune for what you use.

My 93 supercharged continental produced similar results that you got, with the exception the boost went a little higher (9psi-ish). On the other hand, my old twin turbo 451cid Dodge pickup really liked gas at WOT, and under boost (20psi-ish). I dyno-tuned that beast to peg the A/F meter to about 9:1. Anything more than that you'd see gas vapor fly out the tailpipe.... anything less than that the engine was running lean. But the truck was big, heavy, geared wrong, and I'd often demonstrate the configuration by lifting the front tires off the asphault (with slicks out back). Without slicks they'd just spin endlessly.

Fuel good. Your engine wants more.

 

I agree, those A/F ratios are fine. Just make sure you keep using 93 octane.

I bet that little grocery gitter is fun!

 

I think next up will be replacing the MAF with a bigger one as I peg it at 4200rpm...

Then I will have a custom tune done.....