I have a GTX 970, 16 gigs of ram and a FX 8120 processes and I need to turn down the graphics to low to get 60 fps on gridmap, anytime there are two vehicles in game at the same time my fps just dies. I am able to run Grand Theft Auto 5 on med to high setting at 60 fps but I cant run beamng drive? I hope there is someone that can help me.
Your CPU is bottlenecking you. Infact, the FX 8120 scores are quite low on benchmarks. And since BeamNG.Drive requires a proper CPU to simulate the physics in realtime, that's your issue. It is also probably limiting you in GTA5 (Even if it's not as CPU intensive as BeamNG.Drive), I'm able to push it almost to max on a 970.
You should probably get an i5 4460 and a good motherboard as AMD's processors arent that great for playing very CPU intensive games like Beamng.