Am I likely to see an upgrade in bhp from swapping my forester tf035 turbo to a td04 wrx turbo and centre decat pipe with out a map

 

No expert but I 'assume' any change like that will require a re map

 

Totally agree a map is needed.My std tf035 turbo has the start of the death whine and ive bought the wrx turbo to replace.I was going to fit it and have it mapped at a later date when ive done the extra mods so im not having the map adjusted every 5 mins