Formula 1's funding model is "starving" smaller teams, claims Marussia refugee Timo Glock.Glock has had to leave F1 for the DTM touring car series for 2013 as Marussia replaced him with a pay-driver.Glock said: "I learned the hard way that it is extremely difficult for a small team to come out of the cellar. The top teams get a lot of money from Bernie Ecclestone, starving the small teams a little bit."Finding partners to improve the budget is increasingly difficult."THE COST OF PAY DRIVERSIndeed, the smaller teams are apparently becoming increasingly reliant on "pay drivers" to boost their coffers, and it is expected that - like Glock - the next victim of this trend will be Caterham's Heikki Kovalainen.Glock said: "There have always been pay drivers. I won't say that they have no talent."Pastor Maldonado and Sergio Perez have proved that you can have good partners behind you and drive fast as well. It's perfectly legitimate."But it's too bad that formula one is increasingly developing in this direction."He said Marussia in particular was caught out by the political wranglings of a few years ago, when small teams' interest was sparked by former FIA president Max Mosley's plans for a budget cap.Glock said: "The approach of building a car only with CFD could have worked if the budget cap had come in but it didn't."We then determined early on that you can't do it just with CFD, you also need the wind tunnel, and by then the collaboration with McLaren had come too late."In 2012, we showed that we can make a step forward, and found more than 1.5 seconds (per lap). But in order to make the big step, you need double the budget."Der Spiegel reported that Marussia only managed to vacate Glock's cockpit for 2013 after paying him his retainer.He responded: "Then they know quite a lot, or more than I do. On contractual things I can't say much. It's mine and Marussia's business only."As for whether he has closed the chapter on F1, having reportedly signed a three-year contract with BMW, Glock insisted: "Let's wait."At the moment I'm focusing on what lies ahead. What happens in the next few years, we wait and see."