is there a maximum speed of flying without a license?

[Mr Man]

As long as it's big enough and the people there know.

yup

 

[Thomas B]

Recreationally, if you are flying under the rules of an FAA approved Community Based Organization, such as the AMA or FTCA, the 100 mph speed limit does not apply.

My home RC field has a good number of turbine powered jets, which all exceed 100mph. Lots of our larger EDF jets are somewhat faster than 100 mph, not to mention electric and glow pylon racers, some larger warbirds, etc.