Hi Mike,
I want to properly data log my '05 F150 5.4 3 valve truck with a wide band O2 sensor on a dyno. I already am running your 91 octane performance tune on my stock intake and exhaust, which is awesome, thanks.

Anyway my question is... once the truck has been properly datalogged and I change the intake and/or exhaust. Would I need to use a wideband O2 sensor to datalog again or would you be able to reliably use the sensor voltages to tweek tune for the new setup? Would the voltage curves remain basically the same only with a different reference plane?

The reason I ask is that I haven't yet decided to keep this beast quiet or go with more power and sound. Yet I would like to get it dialed in and be able to datalog using my Xcal2 for future upgrades if needed without having to go to the dyno again.

Thanks for your help and the awesome tune,

Andy Watson

 

HI Andy,

Good to hear from you!

The deal is, if we are talking about any 2004 & newer F-150, then if you make any change to the air intake tract AFTER we have provided your baseline tuning, then yes, you DO need to do the complete datalogging all over again, to include both no-load and load (full-throttle)info, so that we can see the effects of that change.

Things like a cat-back exhaust are not going to alter the A/F's, that's OK,.Same goes for e-fans & underdrive pulleys, and even shorty style headers.

But when you change the air intake tract on a 2004 & newer F-150, that is a BIG change in the mass air system's effective transfer function - how many volts it outputs per CFM of airflow coming in, as you are completely changing the design, shape, routing., and/or interior volume/diameter of the air intake tract- and that makes a BIG change in the MAF TF in most cases - so just remember, any time you change the air intake tract after we have tuned that vehicle, you will need to datalog it as per our docs, and get that data to us, and then we will work out a fee that reflects the actual amount of work we have to do to once again correct those A./F's - and keep in mind that this typically requires more than just one round of datalogging and adjustments to the tune, that is the norm especially in the 2004 & newer trucks, it's just the nature of their MAF system's operational characteristics.

We always prefer to see the actual wideband A/F's, that is the way to get the most accurate data - now in lower-powered normally aspirated gas engines, we can sometimes use the )2 sensor voltages instead, and that will allow us to make a "gross" adjustment in many cases - but if you have the ability to get to a dyno or use an LM-1 to get the wideband A/F's, then that is the way to do it properly, and remember, it's not just the A/F's or just the O2 sensor voltage we need - it's ALL of the parameters in our docs - we have to have the engine RPMs, MAF voltage, spark, fuel trims & everything else in order to be able to correctly dial it in - so it's just not the A/F's, it's all the data, otherwise we have no idea exactly *where* in the MAF TF to make the appropriate changes.

For any more details on this, just give us a call & we'll be happy to go over this with you, OK?

Good luck!