The City of Colours street art festival has launched a bid to raise £15,000 from crowdfunding website Kickstarter.
The inaugural event was held in Digbeth last September and attracted around 9,000 visitors.
It is free to attend and open to people of all ages but costs £85,000 to put on, with some of the costs covered by the Arts Council and private sponsorship.
Donations from £1 to £1,000 are being requested and there is a range of 'rewards' available in return for donations, ranging from VIP passes to the event, limited edition prints, to having a donor's face immortalised as a piece of street art.
Festival co-founder Becci Wright initially planned to expand it to two days following feedback from visitors but told the Post the team had decided to make the one-day event bigger and better.
A day of live painting, music, dance acts and workshops will run from 10am to 6pm on September 12 while the following day will be classed as a viewing day with food and some live events, from 11am to 4pm.
Ms Wright said: "The plan is to host more activities on the Saturday while the Sunday will be similar to last year for viewing but with more happening.
"Last year was the first time we had run the event and moving it from one day to two would require double the funding. We want to refine what we are doing rather than stretch ourselves too quickly.
"The number of music stages has increased to eight or nine and there will also be more venues taking part this year, rising to around 15. We are hoping to expand it to two full days of activities in 2016."
Organisers say they are hoping 15,000 visitors will come to Digbeth to witness hundreds of street artists, graffiti writers, musicians and performers and have launched the Kickstarter campaign to ensure it stays free to attend.
"Promoting community cohesion is one of our key objectives and it's very important to us that the event remains accessible to all," Ms Wright added.