My new igo-s with the air hole opened up, a lot. Nice loose draw like I prefer and great vapor production. Awesome little beastie.
It's on my 1300mAh vision spinner running a 2.3ohm microcoil cotton wicking
Try 2 ohms and crank the voltage all the way up to 4.8 V. That will put you close to the cutoff amperage of 2.5 A and let you run the highest possible wattage (about 11.5 W), and still should be safe. That is, if you are looking to get the most intense vape possible off an ego.