Get results from content indexed from other site with search api
My guess is that you will not be able to do this with the standard search view process.  I believe that views does some linking of results to content that exists on the site.  So remote content will be filtered out.

That said, you can get what you want if you use the native Solr query requests.  These return the raw json (or xml) data from the server.  You can use this with custom code to display your results.

See the solr tutorial on how to create queries.

A site I used to manage used this with Angular.js to manage some really complex searches.