in short, the ride height changed but all reference files(chassis HDV TBC TGM) were the same on two cars After a long while my project car stock MX5 ND was about to drive still a lot of flaw but it works fine. so I copy the previous folder name "test_car" rename it "mx5"and clean out materials...etc to a clean set as the folder in R't side of the picture rename files and check car body in showroom, everything looks fine. but the in game difference is huge....... the left side red car is origin "test_car" / right side "MX5" not only visaully the car "sank" into ground, the tire(maybe chasis?) phyics too the tire in right "MX-5" with larger contact patch and more frictions too (by the way, I also found this issue at another MOD of GT86) but I didn't change any setting in HDV, suspension.ini or anything nothing change but rename and the car physics is changed??????????? any clue of this?