TSI = TFSI, just like DSG = S-tronic. it's just different nomenclature between Audi and VW. even the Audi TT and A5 (which now share the EA888 engine with the MkVI GTI) have "TFSI" written on the back of them.
anyhow, the Golf R has the same engine as the TT-S, and by extension, the same engine as the S3 (EA113 vs. EA888). the engine is basically a mapped Eddy engine, but with stronger internals. the Ed35 has the same engine as well.
no offence to anyone who has one, but you have to be licking windows mad to spend that much money on a Golf. a properly specc'ed .:R is near as makes no difference the same price as an RS3!!! and i think the RS3 is a pointless exercise when you could buy a very nice used A3 2.0T quattro/A3 2.0TDI quattro and map it AND get a very nice used Cayman for the same cash and not have a car that's compromised.