Alastair Seeley tops Superbike practice after heading the earlier Supersport session.

The Carrickfergus man believes he can go even faster in Thursday's second Superbike practice on his Tyco BMW.

"We didn't go for an out-and-out lap on the Superbike today," said the 37-year-old, who has an all-time record 17 North West 200 wins.