How to make an RSS feed display everything?

I have a wordpress blog that is auto posting posts from the rss feed:
this site wouldn't let me post it, but I hope someone knows what I'm talking about.
If the post is really long, then it doesn't display the whole post on the rss feed and then my auto poster doesn't detect it and post the whole content.

For example if you look at the first thread on the rss feed called, NGP: Launch games official, pre-E3 info explodes then you will see in the rss feed it cuts off but if you go to the actual post, it has much more than what is displayed in the rss feed.
I am wondering if there is a way or a service to make it so the rss feed displays everything?

There are a couple of solutions out there to fetch full feeds content, like wizzardrss or FeedsAPI , you might try the las one because it even supports RSS to email blogging

Check this out: http://www.blackhatworld.com/blackhat-seo/blogging/431214-free-full-article-extractor.html