19" Stock Rays wheels powdercoat project

Phimosis

I'll post a couple of pictures of the fronts only at the end of this post. A good deal of the ammount of rolling over the edge of a tire you get is determined by your camber. When the car was stock, I would roll over the edge of the 245 front and it would understeer under hard cornering, but the camber was -1.1 degrees. When I lowered it and put sway bars on, I had -2.2 camber and it didn't really roll over the edge, but it would still understeer. It was just too much weight for that compound of tire, car weight and tire width. Then, I went to the 275 width and kept the camber and toe (+.1 degree) the same, the understeer went away. The steering is still very crisp, but it does wander a bit more over pavement grooves. I don't feel any sidewall movement compared to the 245. It's just more grip. Also, the 275 width is still within the recommended range for a 9.0" wheel. The 2010 Camaro uses a 275 rear on a 9.0 inch wheel. The 305 rears are out of the recommended range (10.5" minimum recommneded), but still look fine... no bulging....See page 4 of this thread. I don't feel the rears wander at all either, but I'm running 2.2 camber there too. The car with 305 rear and 275 front is a beast compared to how it was directly before the tire change. I ran the same setup on a 2006 Corvette Z51 and had the same results. Rear tire spin was less, able to get on the throttle in corners earlier and understeer all but went away (hard street driving). That car has 9" front, 10" rear with 245 and 275 Goodyear F1's stock, which I changed out for RE050A's 275 front, 305 rear.

In looking at these pictures, remember that the tires have a recessed bead to save your wheels from curbs. The tread on the 275 is still not a wide as the wheel.











Oh, one last point. You can see how far out on the edge this tire has been scrubbed, and this was after a hard canyon drive yesterday. If you watch in the video below you can see mid corner steering adjustments, but it is because of slip angle, not double apexing. The video doesn't give you the sense of speed, but the slowest point in there is 3,000 rpm in 2nd gear which is 28 mph, despite numerous corners with 15mph recommended speed and with blasts up to 75 mph between corners.