Radios for karts

Has anyone had a radio setup that would work for shifter karts?  We want to have two drivers and a guy in the pits all talking to each other.  

What at should I be looking for in a system like this?  Im pretty clueless on electronics

If you're racing in a karting event, check the rules.  Radios are illegal in every kart race I've ever been to.  From club to national.

-Rob

In reply to rob_lewis :

Good to know.  This is just for us for fun use.  I’m lucky that I have access to a private track and we just run what you brung against some other locals so no one will care

Maybe try bike to bike comm systems? Should be reasonable price and easily adapt into helmets.