No i don't think there is, as the ECU "engine control unit" is programed to the limit,the only way would be by Ford and with there own PC software...Anyway 70mph is the National speed limit on Motorways,so why you need to go faster??
The speed limiter is for more than just the engine speed if you don't have quality tires rated for more than that speed and at heavier weight then you would destroy the engine and ruin your warranty but it should not drop out completely take it to ford and have them take a look may need a rom update that only ford can do and now with computers get ready for mandatory speed limits set by transmitters on the road that won't let you go faster thanks to Navigation systems.