Nichrome just reads really low compared to kanthal. Helpful for upping power when you're working with parallel, but difficult to balance out for series. You wind-up overpowering any coil you can reasonably fit. Would absolutely recommend you stick to kanthal for series.
The idea with series is to do builds that are a tad aneimic (don't draw as much current for their size.) So wire with really low ohms-per-foot are out. It's just overkill. Use kanthal for your core. For duals, 28 or 26 are ideal. I prefer 28, as it doesn't hold onto as much heat, which can become an issue with the lower gauges.
Play around in
Steam Engine for a bit. There are all sorts of builds you can do. Take advantage of the heat flux calculator - go over into the battery tab and see how many watts your target resistance gives you at 8v and plug it in back over in the heat flux calculator before plugging in builds. A .4 gives you 160w @ 8v, so you plug that into the heat flux calculator to see how hot the build will generally be. Very helpful when dealing with series voltage and such. Just keep in mind that if you change the resistance, you have to go back and recalculate the wattage for 8v at that resistance.
I like dual 38/28 kanthal fused claptons a lot. 7 wraps @ 3mm is ~4 ohms. Single cores work nicely too. Something like a dual 40/24 kanthal single-core claptons aren't bad, either. 10 wraps @ 3mm-3.125mm yeilds .45-.5 ohms. You could also try a dual 36/28 kanthal clapton. 8-wraps @ 2.5mm for ~.7-.8. Don't be fooled, it's feisty in smaller, slightly more closed-off rdas.
You have the right idea with claptons. Stick with them on the cricket. You have 4 times the watts per ohm. That's also 4 times the heat. The added inactive mass gives all of the extra heat somewhere to go. Standard coils tend to a. heat up ridiculously too fast, b. heat up impossibly slowly, take up too much space, and hold onto enough heat for you to cook an egg on the face of your mod, and/or c. have major wicking problems. The only way I've found to get around problem c with the really big coils is to up the diameter past 3mm. Sometimes 3.5mm or even 4mm is necessary.
If you must use the nichrome in a standard dual, go really big. 10-12 wraps on that 3mm should get you somewhere nice. No telling how that'll wick. Might have to up the diameter. Really never bothered much with nichrome on series because of how much current it pulls. It's probably workable, just really impractical, imo.
