Might jump in here. If i sub ohm 8mg freebase where should I start with nic salts (0.4@50w). Some say more, same etc.
Yep its just to try, see if there is any different effect, duration etc.
If, you are trying salts, for comparative purposes... and, you intend to use the same hardware, and set-up... it seems logical to
me, to use the same (8mg/mL) nic level. Then, based on your experience/perception, you can decide to increase/decrease as desired.
The high concentrations, commonly seen in small pod systems (like the Juul); is simply necessitated by their inherent low power, low vapor production. The vaper is getting less vapor... therefore, the vaper requires a higher beginning nicotine concentration (in the vapor) in order to feel an equivalent level of satisfaction.
Keep in mind; Big Tobacco sought to add ingredients, to create/release
freebase nicotine (vs. salts; which is tobacco's natural nicotine state);
because is was more immediately bio-available, and satisfying (and therefore, sell more product).
I personally accept very little of the "urban mythology;" that seems to revolve around nic salts' popularity today. As a personal user of both (freebase, in my regular vape gear @ 18mg/mL; and salts, in two different pod systems @ 50mg/mL), the only notable difference
I can perceive, is the absence/reduction of throat hit...
at comparable levels.
This makes sense to me. Freebase nicotine is (relatively) highly alkaline; which is irritating to the soft tissues of our airways. Adding an acid, to bring the pH level to a more neutral balance, removes/lessens the throat hit. And, as a byproduct, converts freebase to salts.
As a strictly anecdotal example: I diluted a small portion of my commercial 50mg/mL nic salt e-liquid, down to my normal 18mg/mL strength, using plain PG and VG. I then vaped it in my normal hardware. other than a total absence of throat hit (compared to my usual 18mg/mL freebase), I found no significant difference. If anything; it seemed a little less satisfying, and I tended to vape with a bit more frequency. (I went through my one-tank tester in about 3/4 of the time it takes me to go through the same tank filled with a freebase-based e-liquid. Though, this is entirely circumstantial, and could be due to my increased curiosity/interest.)