Wrong search results for products name with space

[foxskav]

Hi,

I have problem with results:

In my shop i have many products like "vitamin b" "vitamin c" "vitamin e" etc.

So when I try search "vitamin e" i have results with every vitamins but "vitamin e" is too far.
Additionally I have category "vitamins".

I know presta split every words form searchbox and it try "vitamin" and "e". In end "vitamin" have bigger weight from "e". 

I tried change minimal lenght to 1 - but then there is so bad results.

I tried change different ways weight for index - no good effects. 

I tried give more weight to tags and add "vitamin e" but tags cant have space include.

Someone can help me?

Edited January 31, 2018 by foxskav (see edit history)