No. An official version of Forza Motorsport 4 was never developed or released for the PlayStation Portable (PSP). Forza is a flagship Microsoft intellectual property. It is completely exclusive to Xbox consoles and Windows PCs. Sony’s PSP never received an official port.
: Highly suspicious files hosted on third-party sites that may contain malware or viruses rather than a playable game. forza motorsport 4 psp iso exclusive