Right escort boffins

am i right in saying the si has 105bhp unless its a 3 door which has the same as the gti 115bhp


what would be needed to be changed to gain the same ponnies as the 115 version before aftermarket goodies are fitted ??

is it the ecu and throttle body , maf sensor etc ??

thanks

id assume theres less chance of a si being hammered like the gti aswell