Come check out http://cmsracing.com/champion/forums/content/ They have all types of racing: rFactor 2, GTR 2(P&G historic mod),iRacing,rally series.
www.ussimracing.proboards.com we have just launched and are preparing for our first event on rfactor 2 as soon as the 64 bit build gets some kinks worked out! we are based in America but will offer races for overseas guys aswell!!!!!!! please come and sign up!!!!!