Sha512(pass.salt), 128char salt.

[philsmd]

did you try -m 1710 = sha512($pass.$salt) ?

see https://hashcat.net/wiki/doku.php?id=example_hashes

there are some differences with length limits between optimized (using -O) and pure kernels (without -O).

also make sure to check whether the salt is in hex (using --hex-salt) or it's used AS-IS (no --hex-salt)