The only torture novel I have read was 'Geralds Game' by Stephen King.
It is torture, but you may find it a bit boring, compared to what your taste is.
Summary of the book:
Jesse Burlingame and her husband want to be alone and go up to there cabin out in the isolated mountains. Gerald and Jesse play a game, and Jesse ends up handcuffed to the bedpost. In a violent outburst, Jesse kicks Gerald out of self defense-- still stuc to the bed-post. He lays dead on the floor, and Jesse must survive all that the mountains-- and hell, can throw at her while she is tied to the bed, fighting for survival.
I found it sort of disturbing, but a fairly good read.