Hi, and welcome to Vaping Underground. I am glad you stopped by and hope you look around and like it here
There's a lot of scary in your statements. dual coil 5 wraps with a 3 mm diameter should be around .28 ohms with A1 Kanthal. I usually make a single parallel build (where both coils are wrapped together on the same side of the atty so it looks like a big single marco coil.)
The Dark Horse has several different airflow options...when you say you're not satisfied with the vapor what do you mean specifically? is it too hot? too cool? Not enough? not enough flavor? too much vapor? Need a little more info to help you out here bud.
Also, some might disagree with me but building without at least an ohm's checker is dangerous and not recommended ...I don't know how long you've been vaping but I knew the aprox. resistance of your build by just what you told me so far because I build simular coils. You need to get one, for safety's sake. Also, for safety's sake...you need to know what kind of batteries you're using...the brand name is a good start but Samsung makes several different kinds of 18650 batteries. Some like the 20R and the 25R are high drain IMR batteries which is what you need especially for builds down in the .2x range with their 22 and 20 amp continuous drain ratings...but Samsung also has batteries for sale in vape shops and online like their famous pink 26F which is only a 5 amp continous drain rated battery and is quite dangerous to use with a build with such low resistance...
I am more than happy to answer any question you have to the best of my ability or point you in the right direction of the answers you seek but basically battery safety knowledge and a knowing how to use an ohm's law calculator is pretty much required if you want to safely build RDA's and use them on mechs, which have no build in safety protection where as the regulated mods do. Mech mods are only as safe as the knowledge of one using them.
Tell me what's on your battery's, if they have any writing or what color they are and more about what you dislike about your vapor production and get an ohm's meter asap and we will get you vaping happy in no time at all...
There are many good ohm's law calculators you can download right on to your phone if you have an Android device, I am not sure about apple but I think they must have something simular. and here is a link to a simple ohm's law calculator you can use online.
http://thelocust.net/ohm/