I've noticed that when my Novak gets hotter and hotter, the breaks get crappier and crappier (especially with the older bonded rotor; not so much with the sintered one). If you're running the bonded rotor, that may also be a reason why the brakes are so iffy. I had to set the braking very high on my XBR to get the type of braking I like, so for the mamba max if you're running it off that, try setting it to 100% braking if you haven't already. Perhaps a slightly more agressive brake curve would help too.