Trying to figure out wheel offset. Can you check my math

[2002_red_gts]

Well I’ve ran the number for about an hour to make sure this is right and here is what I have gotten
Stock wheel back spacing
18x10 front 2"=50mm offset
18x13 rear 2.5"=63mm offset

Now minus the spacer width that people are running to make the stock wheels flush which takes away from the offset.
front 50mm-10mm= 40mm
rear 63mm-25mm= 38mm

now subtract that to show the difference from the 20mm offset off the BBS's
40mm-20mm=20MM
30mm-20mm=18MM

So that is what should be needed to take off the wheels to make them flush which would be in inches

20mm x .0393= .786'
18mm x .0393= .707'

Does this seem right?

Now before I get flamed I’m not saying I’m going to do this I talked to a large commercial metal and machining company in San Diego that has all the high tech tools to work on these. I just need to know what is needed so they can determine if this is possible or not. Being forged wheels they are confident that if it’s not too much to be taking off that it will not be effected

 

[mjorgensen Woodhouse]

If you are talking about cutting down the wheels I don't think I would do that, but that's me. If you are going to you need to know if the calipers will clear the new cut down wheel, clearance at the caliper/spoke is what will determine if it will actually work.