CART Indy cars used to come to Cleveland.
There was a grassy area away from the grandstands were two cement barriers and fencing separating you from the track and you could get pretty close to turns 9 & 10. You couldn't see much because the trackside walls were probably 5 ft tall and you were probably 20-30 feet from the track behind 4 ft tall wall. Nobody would go there because you really couldn't see much, but one day me and a friend stood there for a hour and it was incredible.
As they came into turn 9, the tires would skid and bounce at a high frequency during braking. Almost like when airliners touchdown on a runway but with a deep sound. The ground would shake like an earthquake as this happened. On the first lap it was like some oversized train was rumbling past you. Once the cars spread out a bit it was clear what was happening.
As they exited turn 10, the transmission shifts were so violent you could feel them through your feet. Like someone was dropping bowling balls on cement at your feet. That little pop you hear on TV sounds like a head on collision when you are that close.
The forces and sounds were incredibly violent at that distance. It's truly amazing. As TheSneeze pointed out, it really can't be described...but I tried!