Soon you will be able to buy the WW 11.75" GT rotor 6 piston DP caliper setup to fit 15" wheels. I am paying to have mounts made and the pattern will be available so easy to order and for a good price. There are much cheaper rotors that fit this setup as well, pads are cheap and a ton available.
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Rear brakes are a bit more effort but I am making mounts right now for 4 piston WW calipers with parking brake arms, 11" GT rotors, modified knuckles, etc....but rear brakes for a bit of work with the same great rotors but are much less in that size and pads are less and many options as well.
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Depending on cost to mod the parts unless you do it yourself I imagine both front and rear sets with pads and SS lines might come in under $2k for the front and rear
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Do the hub re-bore and you can get 15x8 in the 12 lb range for $120 or so, roll formed, 15x9 $130 range, roll formed and 13 lbs as well as the new version of the 15x9 12 lb roll formed UL6 which is a beautiful wheel but will have to be careful to ensure they fit over the brakes.
If they do later on I will sell my 15x9 wheels and get them as always wanted the UL6 but they were no longer sold while working on the new version.
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225/45/15 RA1, $40-80 each fresh from race teams, I always get the best as shipping costs the same, $400 or a bit less a set to your door, and you can get A6, R6, R888 and others.
My 15x9 with 225 tires, balance weights, aluminum valve stems, 31.6 lbs per corner!
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There is a method to my __________after all