I have 17" 275/40 Toyo Proxes RA1 all around, on Cobra R wheels, 5.95" backspace. They work fine, no fitment or interference problems after 5,500 miles. I'm running SN-95 spindles and IRS. There are some pics at the site by my signature below if you'd like to see how it looks. Hope to have the body back from the paint shop early next week, if you'd like to see it not in primer! Good luck.
I don't know too much about this but from what I've read it is important to increase the rim width if you increase the tire width in order to maintain a good footprint. If the tire is wide but the wheel is narrow the tire is curved upwards and sits more on the center than the edges.
Be careful using anything wider than a 9" rim up front. As is, the wheel gets very close to the adj. upper control arms. 9.5" may work but backspacing would be very critical. Normal backspacing for 9" rim is 6".
I've heard some say that the 245s are a little better for steering effort and control in autocross. I'm still undecided on exactly what size tires I want to run (although they will be on 17" wheels), too. Would somebody with some track experience please comment? Thanks.
Wow, this thread has gotten some good feedback. I have Cobra R 17x9 Rims all around. My wifes 2002 Camaro SS has 275's all around and looks and handles great, plus can rotate front to back. thought it would be nice on my Cobra too. Thanks for all the comments.
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