There are two types of levels on WK: those called fast levels (1,2,26,46,47,49-60) and the normal levels. The fast levels can be done in 3 days and 10 hours while the normal levels can be done in 6 days and 20 hours. Now, there’s a script that helps with reorganizing the radicals and kanji to appear first on your lessons, which will allow you to go faster than if you had to go through a pile of vocabulary and only then do radicals and kanji. However, the limits will always be those I mentioned above. What the script does is making it more practical for you.
Here’s a mini guide on how to go fast on Wanikani that I wrote a few months ago:
The link to the script is on that post. I wrote that guide for people that have already been using this program for a while, so if you have any questions, go ahead 
Also, as a “proof” of worth, I finished Wanikani in 368 days without any previous knowledge of the language (just the kana).