A few days ago I got new rotors and pads (R1 concepts e-line) and new rear tires installed on my coupe. All of a sudden, my car now feels like a boat on the road, instead of a car--it feels like it's floating instead of staying planted to the road like before and it's scary. At first, I thought they just put too much nitrogen in the tires and that that was the problem, so I checked it and, sure enough, there were 41 lbs. in the back and 31 in the front, so I took it back to the shop and they corrected it (35 lbs. now).
Unfortunately, that didn't help and last night, while taking a freeway on-ramp with a slight curve at the same speed I always do, the car suddenly hops sideways ~2 feet to the left--twice in a matter of a second
and I thought I was going to lose control of it. Fortunately, noone was next to me in the left lane and the VDC kicked in. I checked the lug nuts on all the wheels and they seem tight and the alignment is slightly off, but not bad, so I am stumped at what could be causing this.
Does anyone have a theory for what could be causing this to happen? I don't feel safe driving the car right now!
P.S. Before this started, I had Toyo Proxes T1Rs in front (same pair still--good tread remaining, but feathered on the insides) and Falken FK452s in the rear and they were pretty bald, but still hugging the road like they were new. The new rear ones are T1Rs, like the front, so they match now.