Hi DrScoles, I've done 4 Habu 32's with P-20's over the last few years, and a friend who also did one noted that there is vastly more intake area than a turbine needs as it was designed for an EDF unit. The same holds true for this Avanti, so I think you can safely reduce the intake area and use a single tank easily. On my last Habu 32x I moved the tank back to the wing former, very close to the starter motor as in your photos, and thereby reduced the intake area by about 40% I'm guesstimating. It still runs at the same EGT and as stable as always. It got the fuel closer to the CG as well. I agree that it is a good thing not to change too much on this test installation, but keep this in mind for the future as its an easy mod.
Thanks for doing this thread, much appreciated! I have the K45 on order supposedly shipped but looks to be stalled over the Pacific somewhere, and I'm hoping to get an Avanti in the fall shipment, if not the June one.
Thanks again,
Len