From a 1070 to a 1080TI, worht it?

Hi guys,

6 months ago I mounted my MSI 1070 on my rig (i5 6600K @4.6 ghz, 16 GB ram DDR4) 

But since this, I purchased an Oculus Rift, AND a motion sim,n so now the immersion factor is incredible! 

My computer is wonderful but when I put the VR headset, on games it's still perfect (like PCars 2, Dirt Rally, IL2, DCS) but for my main sim X Plane 11 or sometimes P3D V4, the VR is difficult because I don't have any FPS (if I want something minimum eye candy)

So my question is, coming from a 1070 to a MSI GeForce GTX 1080 Ti GAMING X TRIO will worth it on vr??

For non VR games (or optimized VR games) I know that It should be useless, but what about XP11 and P3D V4?

Regards