here is what I have found experimenting with the ipv4, ni200, and my subtank mini
0.062ohm 28g ni200 2mm id bout 5 wraps at 50j 380deg it produces decent vapor, great flavor, but it only fires at 2.73 volts
0.117ohm 28g ni200 3mm id bout 8 wraps at 50j 380deg produces more vapor, same great flavor, fires at about 3.67 volts
to me, and I could be wrong, but with ni200 and temperature limiting higher ohm = bigger clouds
I got some 32g and a couple attys with more room for coils coming, going to try to hit 0.4 and see if my theory holds true.. will update once I know