ok is the vamo v5 a RMS and non regulated device like the Zmax?
You could not be regulating the input to the coil and just scorching it up a bit.
You could be having a reaction to the pg they use or the vg they use, not all pg and vg is the same.. some tightens up my chest pretty bad if it is on the low end of quality.
You could also have a knock off coil or a possible hot spot in it.
Having a Vamo V5, I can answer that...
Vamo has the option to go into either Means or RMS mode. It is regulated. I suggest going into variable wattage mode instead of variable voltage.
Second... tightness of chest... if you are getting more vapor, others have suggested going to a more VG based liquid. I tend to agree with them. The higher the voltage/wattage, the faster you burn the juice. That opens up a whole slew of possibilities... Like Nasty said, you could be burning your wick a bit. Second, you could be getting more nicotine. If your coils are running hotter, It could vaporize more than what your EGO could handle. Because of that, juices may have different reactions when run at a higher voltage/wattage/amperage. A spinner 2 has a max voltage of 4.2v.... I know with my twist style battery, the voltage drop is fairly severe at first and stabilizes a bit at the 3.8 volt range... even when cranked up, it supplies 4.2 for a very short amount of time.
So, my suggestions would be: 1) Try lowering the PG content or nic level. You can try both by getting some pure VG and adding some to the bottle you currently have. It will mute the flavor, but you can mix just one tank full to see if you're heading in the right direction.
2) Try lowering the voltage and switching to variable wattage to your current setup. See if that can be a quick fix.
3) Keep an eye out for the juice flow to the wick... if you're getting dry hits, you'll get a bad taste and a big throat hit. If your coils are choked off too much, a quick fix might be to block the air intake and lightly suck in.. that will draw more juice into the coil. do ti too hard or too quick though, and you'll flood the coil.
4) Try a higher ohm coil if the above doesn't work... it could just be you're heating your juice up too much. Higher ohm coils on the same voltage setting will cool it down a bit..also, it will have the option to raise the voltage up for more vapor (but then you get into the heat issue again)
So, just experiment a bit. If there's a local vape shop close by, you might want to have them take a look at your setup and maybe they can make some suggestions.