A quick update:
With the boost building at the lower engine speeds, the drivability is beyond a subtle difference. Being here, in the Springs, level roads are somewhat a rarity. So, it is up and down most of the time. What has been found is that the transmission (AW4) wants to be in OD, TC locked by 1500 rpm. This is just under 40 mph given my final gearing (4:56s and P285/75R16s). On a rise, it is making the better part of 3 pounds (2.5+) of boost at this engine speed.
May put the original pulley back in. Were this a manual transmission, there would be no issue at all. As it is, I find myself pulling the shifter out of the OD position and into third. Problem with that is that the transmission also unlocks the TC.
What I could use is full manual control over the box. That way, third gear with the TC locked would be a near perfect combination. Child9, are you out there?
The Jeep is a completely different beasty indeed.
As a side note, I recently "proved" out the measurement devices in the Jeep.
1) Replaced the 160 psi gauge on my compressors output regulator with a new, fresh out of the box, 60 psi unit (to gain resolution you see...).
2) Set the output of the regulator to 18psig.
3) Made a quick adapter to connect the compressor to the line providing the manifold pressure to both the F/IC and the boost gauge.
4) Took a reading of the current air pressure as reported by the F/IC. A nice 12.5 psia reading.
5) Connected the air line to the supply line and allowed the pressure to stabilize.
6) Read both the F/IC and the mechanical boost gauge.
Results:
1) The F/IC reported 30.5 psia.
2) Boost gauge reported 18 psig.
Why 18 psi? The boost gauge only reads to 20 psi. I figured it would be easier to read the error if the needle had "wiggle" room. Given that all three gauges (2 mechanical, 1 electronic) matched each other, the odds are that all of them are accurate. It takes three to confirm.
So, the system, as a unit, is accurate. At least, as far as I can test it with what I have on hand that is. Nice thing about this test was that the F/IC was quite happy to operate with the power delivered over the USB connection. Did not even need the keys...
Based off of these results, I can state that the Sprintex S5-210 compressor, connected to an engine displacing 4 liters, will supply a tad over (0.056 pounds calculated) 9 pounds of boost at sea level as long as the stock TB has been replaced. This is in accordance with the expectations Sprintex gave me at the outset of the experiment.