You need to go to mountune and get there map.
EVO mag ran an RS and ST together a couple of years back.Ive copied and pasted the facts below...
""The Mountune mods for ST, on the other hand, amount to a different air filter, a larger intercooler than the standard ST’s and an ECU remap. That’s it. Yet the claims for power and torque – 256bhp at 5500rpm and 295lb ft from 2500 to 4000rpm – look a lot more conservative than the claims for the performance, 0-60mph in 5.9sec and 0-100mph in 14.1sec being pretty much what Ford claims for the RS…
What unfolds at Bruntingthorpe is, to put it mildly, interesting. The bottom line is this – in a straight line at least, the Mountune ST is quicker. There are a couple of places where the extra top-end power of the RS makes itself felt – 100-120mph in fifth, for instance, where 6.7sec plays 7.4sec – but just about everywhere else the ST has it, and in some cases by an embarrassing margin.
From a standing start it holds its advantage all the way to 140mph, between 30 and 70mph it’s 0.3sec clear and in sixth it destroys the RS through the mid-range, taking over two seconds out of it from 40 to 60mph and still holding a half-second lead between 80 and 100mph. The RS would have clawed back some honour by recording the higher terminal speed at the end of Bruntingthorpe’s two-mile straight but for the fact that it carried 10mph more on to the straight from the bottom corner, recording a peak lateral g of 1.03 against the ST’s 0.93. Clearly that butch body kit and big tailgate wing exact an aerodynamic penalty.
But it’s the difference in the character of the engines that’s perhaps most surprising of all. The RS feels punchier, harder-edged, peakier. The ST’s delivery is comparatively languid and has a little more lag – but once it hits 2000rpm there’s simply no stopping it. The bonnet rears up by a couple of inches and it pulls and pulls and pulls. And that sixth-gear flexibility is simply something else. By our reckoning, the Mountune ST must be pushing out at least 280bhp.""
