Hi Artur,
I am new here too, only signed up 5 minutes ago 🥳.
I have just converted my Acme NB16-T from nitro to electric brushed motor. I used a cheap 550 Surpass Hobby motor with 12T (turns), it is also available in 27T and 35T.
I am running a 2S lipo with the 12T. You can see the configuration and speed with this combo in the video I made.
Here is the link, details of the parts are in the description.
I also own a Backwash, so might be able to help further, mine is still nitro at the mo, with no plans to convert just yet. The Backwash is a bit heavier than the NB16-T which is 1:16 scale.
I did see some other useful videos on conversion which I will try and find and post links to.
I hope this helps and good luck with your project.