yes you need to do the fueling.
cheap way is an Apexi SAFC or go for a piggyback style chip or if your feeling flush go for a full replacement ECU.
Before you go to 1.2bar make sure the engine is healthy and that you have a decent clutch and brakes are up to the job of stopping you. Spark plugs will need changing for some colder ones if you havnt done it already and you should consider a FMIC again if it hasnt been done already. I had to get an uprated oil catch tank aswell as the standard one isnt up to the job.
But dont take my word for it as i know next to nothing about cars :lol:
Im sure all the old guys on here will come and tell you how to do it properly