How can I remove all http-headers

ok I have my solution

I just set the right headers in the controller
$this->output->set_header('Cache-Control: public');
$this->output->set_header('Pragma: cache');
$this->output->set_header('Expires: ' . gmdate( 'D, d M Y H:i', time() + 120 ) . ' GMT');
and in nginx
fastcgi_ignore_headers Set-Cookie;

now php controls the cache fastcgi and browser or public caches

Thank you (for CI and all the free stuff)
temi