I'm along with what Shlunky said above about "iracing".........but there is another up to date sim that is gaining popularity as far as all out "Racing goes".
You really , really should check out " Game stock car 2013 " !!
I had GSC installed for about a month before 2013 came out. I re-bought the 2013 title when it came out because I liked 2012 so much. But the GSC 2013.......and some would agree ( wait....not some , a lot! ) of people will agree that it has the best out of the box physics of any car racing game....ever. They have formula , V8 supercars ( <<< my favorite! ) , Karts , mini coopers and many more.......I'm telling you this sim is worth every penny!
I really dig iracing ( even though it can get spendy )......but GSC 2013 is not only cheap , but like I was saying....probably the best dang physics you can get!And it's $25.00 !
You can get it here if interested >> http://game-stockcar.com.br/?lang=en#home