If i was downloading 2 large files at once would having two routers speed it up?

You can only connect more than one router if you have a separate modem.  Most routers have a built-in modem and only one modem is allowed on any internet enabled line.

Ultimately, the speed of downloads is limited by what your ISP can provide at the time.  Their bandwidth to you will be shared by all devices using the internet at that time, irrespective of how they connect to the router(s).

No. Even if you got 2 routers working on your internet connection, you would still be limited to your download speed you get from your ISP. 

not if you are downloading it to the same PC

and how are you connecting two routers to the modem

or do you have to internet connections