If I blast my two year old domain with PBN's, how long will it take for google to punish?

I have this site, I was working on it for 2 years but recently it has become very unresponsive, its a moderate to tough niche. So now as this website is pretty much useless I am thinking one last PBN blast of 150 posts from lover's service. If it works great if it doesn't I move on...

Just wondering if it happens to work how long will the rankings stick? A week? a month? Till the next update?

Thanks