are you playing on a laptop? If so you are most likely overheating your network adapter. Once the network adapter gets to a certain temp, it starts losing packets.
2 things that might work;
first either open up your lap top and clean out the cooling fans, or if you aren't comfortable with that, take a vacuum to the fan exits and try to suck out as much junk as possible.
Also, try getting a cooling pad for underneath your laptop and put one of those reusable ice packs underneath the cooling fans.
If you are working on a desktop, open it up and clean it out. Then check to make sure your modem is less than 4 or 5 years old. Ditto the router. Unfortunately, the modem and router are usually on 24 hours a day and over time start to lose their ability to stay cool. This causes them to lose packets of data coming in or out.
Hopefully that gets you on the right track to fixing the problem, and back on the race track!
Then it is definitely not a heating problem with your computer. It is either your modem, or router. And if it is neither of those, then it is on your provider's side. You should be able to check your connection to random places through a website. Just do a search for ping-test or speed-test. It will tell you how your connection is. The main thing you are looking for is how much data is lost during your connection. Ping should be under 100 ms, and hopefully you have somewhere around 15mbs speed.
Judging from the red S in your photo (syncronization), you might also want to call/email iracing tech support or do a search in the forums to see how other guys dealt with the problem. The tech support team does a really good job and they are really friendly. It might be on iracing's end. I have heard that there have been other guys with similar problems lately.