Very, very high.
Speedhacking alters the frame rate of the game, which TNT collects along with your score and time taken when you send your score. If they see a frame rate that is absurdly high, you will be automatically reviewed. Additionally, if you send a score too quickly after starting a game., you will be reviewed and frozen anyhow.
A much safer way to cheat YYB with Cheat Engine is called "AoB". There's a guide on this site, I'll link to it if I find it.
EDIT: Oh, you mentioned AoB in your post. Just stick with that, don't speedhack.