No. Stick to HN. Trust me. Most domestic portuguese language forums are inevitably full of bike shedders. Most of those that want a higher level of discourse stick to HN and IRC channels for their respective technology. This results in a vicious cycle of brain drain in the domestic forums, suppressing the level of discussion further.
My suggestion is to stick to HN and intl technology channels on IRC and Github and keep an eye out for telltale signs of a Brazilian by the name or other identifying info and reach out to them one by one. You may want to try out HackerNewsers to seed the network initially. http://hackernewsers.com/
Also, get in contact with Diego Remus of Startupi and Diego Gomes of EverWrite.
My suggestion is to stick to HN and intl technology channels on IRC and Github and keep an eye out for telltale signs of a Brazilian by the name or other identifying info and reach out to them one by one. You may want to try out HackerNewsers to seed the network initially. http://hackernewsers.com/
Also, get in contact with Diego Remus of Startupi and Diego Gomes of EverWrite.