@Silver and @Amir. Try building a bit lower and perhaps a smaller coil ID.
Also don't suck like your life depends on it.
Try let the bb do the hard work and press and inhale gently.
I found that the tightish airflow, coupled with a huge coil and a tiny chamber tends to let juice up because of the serious suction we put on the tip.
Basically, suck less hard
Builing a bit lower as in coil height or resistance? I have a 2.5m ID fused clapton coming in at .85 ohm roughly 25W (juice dependent) with the top of the coil in line with the top of the posts. Maybe its the sucking... But then again I don't have as much experience in that department as you do