I dont think too many have changed injectors, partly due to usually needing the ECU tuned to deal with it. Project/hobby car?
I think Tron, Matt Dean and a couple others have decapped the Subaru 560~cc's, and theyre been rated to around 870cc~ afterwards, so thats about a 50% increase. I'd hazard a guess the 175cc would go to around 260cc, and FTO/Magna 275cc could go to 415cc.
There is one or two really big brand companys that sell aftermarket injectors in the 1000cc+ range, these injectors have been proven to be Bosch and Denso injectors but decapped to let them flow much higher than they did from the original manufacturer.