LONDON, England - Mercedes Formula 1 team chief Ross Brawn believes Lewis Hamilton still has much more to offer to the team despite his recent surge of excellent form.He delivered his first win for Mercedes at the 2013 Hungarian GP on July 28 and his form suggests he will be a favourite to win the 2013 Belgian GP.NO LIMITSBrawn said: "When a driver of Lewis' calibre joins a team there is huge expectation but every driver takes a little time to settle in and to understand the nuances. It has taken a little while but I see great signs, particularly in the most recent few races."He is starting to pick up momentum and move in the right direction so we don't know where the limit is. We are on a journey with Lewis and we don't know his limits. It's our big challenge to maintain the momentum."Our hit rate has been pretty good this season - things we have brought to the track have generally worked and we've some things coming up that could give us the momentum to take us through 2013."TITLE CREDENTIALSHamilton remains 48 points behind championship leader and defending triple F1 champion Sebastian Vettel in the title race with nine races remaining and 225 points available. Hamilton believes in his title credentials: "It's too early to talk about that at the moment but it's at the back of my mind. I truly believe in this car. It feels awesome."Mercedes has three wins and four poles from the previous five races - form that has enabled Hamilton to emerge as the highest-scoring driver in the three races leading up to the summer holiday. Stay with Wheels24 for the 2013 Belgian F1 GP weekend.