'22-'23 vs. '18-'21 CAI Measurements

[chuckhammer]

Those of us with a 2022 or 2023 GT are familiar with the changes Ford made to the CAI to accommodate the revised carbon trap and tube insert with flow straightening grid.

I was curious how the old vs. new intake tube inner diameters compared at the MAF location, both with the '22 insert in place and without. I recently grabbed a 2019 CAI off eBay. Below are my findings.

Intake tube ID @ MAF slot leading edge:
2019 - 97.5 mm
2022 - 95.0 mm w/insert
2022 - 97.5 mm w/o insert

The MAF sensor itself uses the same Ford part number for all 2015-2023 Coyote engines: 8V2Z-12B579-A

This means you can remove the carbon trap, its related support lattice, and the tube insert with flow straightening grid and the resulting parts will flow and meter like a 2018-2021 CAI.

Photos below of how I modified mine to mimic a 2018-2021 CAI. I cut off the flow straightening grid several months ago before getting a tune. At the time, I chose to leave the insert in place maintain the tube ID at the MAF for the 2022 factory tune. I have since removed it.

Sponsored

 

[MAGS1]

Just remember that our cars are calibrated with the smaller MAF area diameter vs the 2018-2021 cars. Will be curious to know how your car does over the next several days, if it’s able to adjust enough without throwing a code. The grid insert shouldn’t affect airflow much if at all, it’s just that extra carbon trap that seems to be the most restrictive.

 

[chuckhammer]

Correct. My E85R tune includes the larger 97.5 mm tube ID at the MAF. Amounts to 5% more flow area so the MAF sees 5% slower air velocities vs. the 95 mm tube ID, all else being equal.

 

[Joshinator99]

Just remember that our cars are calibrated with the smaller MAF area diameter vs the 2018-2021 cars. Will be curious to know how your car does over the next several days, if it’s able to adjust enough without throwing a code. The grid insert shouldn’t affect airflow much if at all, it’s just that extra carbon trap that seems to be the most restrictive.

Easier to just do a nice aftermarket CAI and get rid of all the ‘22-‘23 silliness that Ford did. Then you can just swap the unmodified stock CAI back on if you sell or trade the car.

 

[chuckhammer]

Yes, indeed, it is easier but also more expensive. Looks nice, though.

 

[SnowFox]

Just remember that our cars are calibrated with the smaller MAF area diameter vs the 2018-2021 cars. Will be curious to know how your car does over the next several days, if it’s able to adjust enough without throwing a code. The grid insert shouldn’t affect airflow much if at all, it’s just that extra carbon trap that seems to be the most restrictive.

Took out all that garbage day 1 on my 22. No codes no issues. The calibration isn't a static figure based on physical Maf size. But rather the air flowing through. It can adjust withen a acceptable range(the ecus acceptable delta between the points) Pulling this junk out is similar to cleaning a really bad Air Filter. Even daily humidity, tempature, air quality can have a larger impact than this thing.

People think way to hard about this. Take it out. Throw it in a bin and forget it ever existed.

 

[chuckhammer]

If I understand it correctly here's how it works:

- MAF measures flow velocity (not mass flow directly), air temperature (IAT), and static pressure.
- ECU calculates air density as a known function of temperature and static pressure.
- ECU calculates flow area = tube diameter^2 * π/4.
- ECU can now calculate mass flow =
Flow Velocity * Flow Area * Air Density

Since the stock tune assumes the tube diameter at the MAF is 95 mm:
Flow Area = 95^2 * π /4 = 7088 mm^2

However, the actual flow area w/o the insert:
Flow Area = 97.5^2 * π/4 = 7466 mm^2

This is 5.3% greater flow area than expected. Since the engine's demand for air is not significantly affected by such a small change in flow area, the measured flow velocity will decrease by 5.3% to maintain the same mass flow. The ECU now calculates 5.3% less mass flow since it's unaware of the larger flow area.
It only sees the reduced flow velocity.

Short term fuel trims can make up for this +5.3% mass flow error since it will see the effect on lambda (running lean) via the O2 sensors. It's likely not enough to through a CEL.

Sponsored