Also, to add to the above, the Mk6 Golf 'R' uses the older EA113 engine as used in the Mk5 GTI! Must be superior (stronger?) in some way to the EA888!
Just found this on Wankipedia:
"the 169 kW (227bhp) and higher versions have stronger pistons and gudgeon pins, new rings, reinforced connecting rods, new bearings, reinforced cylinder block at the main bearing pedestals and cap, new lightweight aluminium-silicon alloy cylinder head for high temperature resistance and strength, adjusted exhaust camshaft timing, increased cross-section high-pressure injectors, 1.2 bars (17.4 psi) (value only valid for Audi S3(8P)) boost pressure K04 turbocharger with larger turbine and compression rotor (S3, Cupra, GTI Edition 30), of which some components are NOT shared with the lower output variants"