hi dave, i used to have a radio controlled electric scale model of my sports car way back in the 1990ties. never was into nitro, though i love the technique and engineering of them. i was into radio ham things and dx-ing too. i am by no means an expert though.. to answer your questions.. 27hz, 48hz, 2.8 ghz what you refer to is the frequency of the radio control system. in compututing we have bytes, kilobytes, megabytes and gigabytes. in transmitters it is herz, hz, kilohertz khz, megahertz mhz and gigaherz ghz. rc systems have to work in a frequency band, that has been assigned for that purpose in the country you live in. traditionally this was 27 mhz. 1930ties technology. recently other frequencies were added. the latest is in the ghz range, more reliable, more high tech. if you buy a rc transmitter it will have sufficent range. more than a mile is not needed as you have to see the car in order to control it. i recommend you google rc systems, or visit manufacturer`s sites, like this one http://www.graupner.de/en/ to get you started..
you`re very welcome, Dave.. if you go that way you can use it to control a new model in the future too with this in mind give a carefull thought to the number of channels you might need in the future. [ if you buy a 2-channel outfit now, you may have to buy a new one if your next project requires three channels, many systems cannot be upgraded, ]
I am also buy a new nitro rc cars. But I don't have any idea about hz frequency. Thanks for updating me.