Ember get data from POST

I have problem with how to get data send with save(), in params i have JSON like parametar sent with request,and model object which i sent and that is ok, but i can access data with $request->request->all() , i use Symfony\Component\HttpFoundation\Request;. Strange thing when i want to var_dump($request) whit that i don't get any response(nothing) but when var_dump(serialize($request)) i got string but when i searc for my parametars they are not in string!