I posted this in the sticky a day or so ago but I'll post it here too.

I want to take an 18x9.5 wheel with a 45mm or 42mm offset and widen it to an 18x11 wheel to run 315/30x18 tire.

Will I have any problems? I don't want to have to BFH it too much and I don't want to roll the fenders. Also would this effect the ability to lower my car down the road? I am looking to run Sam's spring which I think drop the car about 1.3in. Would these cause a problem?

Also I have heard that getting an adjustible panhard bar is almost nesecary to run such a large wheel tire combo. Is this true or will it just make life easier?

Thanks,
Alex

 

You should be fine with that offset.

Most people on here with 17x11 ZR1's like myself have the 50mm offset, which puts the wheel in further than a 45mm or 42mm offset. A little BFH will be needed, but dont worry, its not hard to do.

An adjustable PHB is not necessary unless your rear end is WAY off.

Also you might run into some rubbing problems later on if you lower the car. Its nothing some more BFH cant fix. It just boils down to your motivation to do it.

Hope I could help.

 

You will not be fine. if you were to widen your wheels from a 18x9.5 to a 18x11, and the 9.5s had a +45mm offset, after widening you will have a +64mm offset. you will need to do much more BFH and possibly even a spacer on top of that. if theyre a +42mm offset, then youll be at +61mm after widening. +50 is probably the most you can go with a 18x11 and a 315 with only a little BFH.
After you widen a rim, all the specs change except the diameter (obviously). The offset is the distance form the mounting surface to the center of the wheel. When you widen a wheel, youre only widening the back side of the wheel, which moves the center of the wheel farther away from the mounting surface and creating more offset.
If you were to widen your 9.5"s to 11" that would move the center of the wheel .75" away from the center. Which translates to approx. 19mm. add that to 45mm and you get 64mm.

 

Thanks for the info. I just recently found that out as well. The new plan is to run a 35mm offset giving me a 54mm offset. According the sticky the safe range is from 45mm-56mm. There is also another member on here that is running some HP's with a 38mm offset bumping him up to 58mm.

I am not to concerned with having to do tons of BFH if the HP's fit. I also don't think fender rolling will be necessary since the offset is so high. The bumpstop is really the only thing I am concerned about. I doubt they will make it all the way back to the control arms.

I am also thinking an adjustable panhard bar might help. I'm not sure how to tell if my rear end is off enough to need one though.

 

Im an idiot. I totally blew past the fact that you were widening the wheel.

I thought it was already a 18x11 with a 45mm or 42mm offset.

michaleg589 is completely right about the new offset.

You might need some tubular LCA's to make some more room for that 54mm or 58mm offset. My 17x11's with a 50mm offset cut it close to the stock LCA's.

Just take measurements of how far each wheel sits in the wheel well. That will tell you how centered your rear end is.