There are no leaked dev builds of Forza for PS3 because the hardware architectures (Cell Broadband Engine vs. Xbox's PowerPC/x86) are fundamentally incompatible. Alternatives for PS3 Owners
You cannot emulate Forza Horizon 3 on a PS3 emulator (RPCS3). You must run the native Windows version on a PC.
The gold standard for simulation on PS3. While not "open world," it offers a massive car list. i forza horizon 3 ps3 pkg download repack patched
Features an open-world city, high-end graphics, and an arcade feel very similar to the Horizon series.
If you are a PS3 enthusiast looking for an open-world racing experience similar to Forza Horizon 3, your best bet is to look for these native PKG titles: There are no leaked dev builds of Forza
To put it bluntly:
This is the closest game to the Forza Horizon "vibe" on PS3, featuring a massive open island and a focus on the "car lifestyle." How to Play Forza Horizon 3 Today You must run the native Windows version on a PC
One of the best open-world racers ever made, fully available as a PS3 PKG.