If the GTB is set up correctly and your batteries are good.. you should be smoking fast! Sounds like you are probably very undergeared. Brushless motors are geared very different to brushed. The power band develops at higher rpms that it does with brushed motors.

Novak publishes a recommended final gear ratio (FDR) in their instructions. Not knowing what car you have, we can't give you the correct gears to run. You'll need a temp gauge to truely set up your car. I noticed that somebody said to get your motor to 160 to 170 degrees.. well.. that's probably too hot.. Novak says you can damage your motor at that heat. Start at the Novak's FDR and temp... it will depend a lot on your track and driving style.

Your car's manual should have the internal drive ration of the transmition. Take the spur gear you are running divided by pinion gear and multiply it by your car's internal drive ration. This will give you the FDR.

Good luck! Once you get it down.. you will almost never have to worry about it again with a brushless.

Have fun!

Jerome