Blac Chyna Fears Ferrari, Beefs Up Security and Bans Ex-Side Piece from Nightclub Gig

Blac Chyna's beefing up her personal security and got her former side piece banned from her upcoming club appearance ... because his recent actions are scaring her.

Sources close to Chyna tell TMZ ... Ferrari won't be allowed in at the Medusa Restaurant & Lounge in Atlanta Saturday night, where Blac is scheduled to host a party. We're told Chyna's hired 4 extra bodyguards for the night in case the rapper -- who hails from ATL -- shows up.

Chyna's camp claims Ferrari's been calling and texting her the past week, and demands for him to stop the harassment having been blown off. We're told Chyna believes he's released revenge porn despite a letter warning him not to, and she also fears for her safety because he's acting obsessive and delusional. His interview with TMZ particularly scared her.

The owner of Medusa, Lil Henny, tells us he will honor Chyna's ban request and make sure Ferrari is not allowed on the premises while she's working the joint.