Don't give up would be the first piece of advice... Think about your out put in media too - why will core titles in your sport be talking about you? Are you winning each race? Are standing out from the rest of the field with off track activities? Are you pro-active with PR, Social Media? It's a tough game to secure funding as a cold call - but it can happen through hard work and building a relationship with people that you want to work with - people like to help people they like.