Being a long time simracer i like pin point response, with the half a second or more lag with Rapture i find it nearly impossible to not crash, as what you see on the screen is half a second ahead of what your input will do.
turn the rapture settings down? its on your windows start menu under "blue ripple sound"
if the game detects you have a 4 core cpu it sets all the rapture settings to the highest and it uses loads of cpu maybe your quad doesnt like it