My guess is the clutch is worn out. When you put in that powerful engine and nailed the gas, the pads didn't have the grip to get a good hold on the clutch bell and you probably melted them trying to get it going.

Also, have you glued on your tires? If you have check them to make sure they are still glued. If you get just a tiny bit of water into the bead of an unglued tire it will slip forever.