Anyone actually running 18x9.5 fronts with 6.5"+ BS?
First, yes, I'm one of those guys running 18x9's with 275/35/18's. 18x9.5's aren't a problem, but you may need a small spacer to keep the tires off the frame when turning with a 6.5" backspace. The tie rod shouldn't be a problem, they do fit inside the rim. Tire to frame clearance will probably be too tight, you'll probably want to end up more like ~6.3" or 6.4" for the backspace. That would be the same inboard clearance to the frame as I have.
tomswheels ran 18x10's with 285/35/18's up front on his Valiant. The wheels he used had a +42 offset, which works out to a 7.2" backspace, but he also used 3/4" worth of spacer. So his final backspace was more like 6.4", and his tires would have been the same distance inboard as my 275's. That combo would stick out .4" further than mine, and Tom pushed his fenders out with a hydraulic ram and rolled the edges.
AutoCross-Crows Landing, CA this weekend!
On that note, if I remember correctly Uchoog1 was running the early AR engineering Viper brakes on his car. Those brakes add a 1/2" to the track width, which would make his effective backspace more like 6.6" compared to a car with 73+ disks. You have to be careful just looking at the backspace of the rim, you have to consider the track width changes with any brake upgrades. For example, my 18x9's are a +35mm offset, so, 6.4" of backspace. But my DoctorDiff 13" rotors add 5/16" to the track, so, my effective backspace is more like 6.2". And then I added a 3mm spacer to stay off the frame, so, 6.1".
But if you compare the center line of the wheel, or look at the inboard distance of the tires, that would be the same as a 275/35/18 on an 18x9.5 with a 6.3" backspace.
First, yes, I'm one of those guys running 18x9's with 275/35/18's. 18x9.5's aren't a problem, but you may need a small spacer to keep the tires off the frame when turning with a 6.5" backspace. The tie rod shouldn't be a problem, they do fit inside the rim. Tire to frame clearance will probably be too tight, you'll probably want to end up more like ~6.3" or 6.4" for the backspace. That would be the same inboard clearance to the frame as I have.
tomswheels ran 18x10's with 285/35/18's up front on his Valiant. The wheels he used had a +42 offset, which works out to a 7.2" backspace, but he also used 3/4" worth of spacer. So his final backspace was more like 6.4", and his tires would have been the same distance inboard as my 275's. That combo would stick out .4" further than mine, and Tom pushed his fenders out with a hydraulic ram and rolled the edges.
AutoCross-Crows Landing, CA this weekend!
On that note, if I remember correctly Uchoog1 was running the early AR engineering Viper brakes on his car. Those brakes add a 1/2" to the track width, which would make his effective backspace more like 6.6" compared to a car with 73+ disks. You have to be careful just looking at the backspace of the rim, you have to consider the track width changes with any brake upgrades. For example, my 18x9's are a +35mm offset, so, 6.4" of backspace. But my DoctorDiff 13" rotors add 5/16" to the track, so, my effective backspace is more like 6.2". And then I added a 3mm spacer to stay off the frame, so, 6.1".
But if you compare the center line of the wheel, or look at the inboard distance of the tires, that would be the same as a 275/35/18 on an 18x9.5 with a 6.3" backspace.
