80LS1T Posted June 10, 2007 Share Posted June 10, 2007 Ok I have been looking at different wheels(I like mine but I would like a dished wheel if possible:bling:). I have been trying to do the math and I think it might work but I'm not 100% sure. What I have now is a 17X7 with +42mm offset with the modernmotor sports 40mm adapters. With this combo I have essentially a 90.0mm backspacing. I have about 3/4 of an inch till the tire would hit the strut tube(19.05mm). Now the rims i have been looking at are 18x8.5 with +20mm offset. So I figure I would have a 91.95mm backspacing with a 44mm adapter(not mms adapters). I know I must be missing something but I figure one of you guys will be sure to let me know! LOL I know I might have to roll the fender lips to make them work but I think it'll be worth it if it works out... Guy Quote Link to comment Share on other sites More sharing options...
Bartman Posted June 12, 2007 Share Posted June 12, 2007 Ok I have been looking at different wheels(I like mine but I would like a dished wheel if possible:bling:). I have been trying to do the math and I think it might work but I'm not 100% sure. What I have now is a 17X7 with +42mm offset with the modernmotor sports 40mm adapters. With this combo I have essentially a 90.0mm backspacing. I have about 3/4 of an inch till the tire would hit the strut tube(19.05mm). Now the rims i have been looking at are 18x8.5 with +20mm offset. So I figure I would have a 91.95mm backspacing with a 44mm adapter(not mms adapters). I know I must be missing something but I figure one of you guys will be sure to let me know! LOL I know I might have to roll the fender lips to make them work but I think it'll be worth it if it works out... Guy I've been looking at going wider as well. Isn't the adaper width subtracted from the wheel width to give you the net offset? 40 mm thick adapter - 42 mm offset = -2 net offset. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted June 12, 2007 Author Share Posted June 12, 2007 Yes that is with the adapters figured in. I found this website after searching for a while. According to that calculator.... Going from a 7" rim with 42mm+ offset to a 8.5" rim with 20mm+ The clearance from stut housing to the inside of the wheel will be 3mm MOREThe outside edge of the wheel will EXTEND an extra 41mm Now if I from a 7" rim with 42mm+ offset to a 8.5" rim with a 35mm+ offset... The clearance from stut housing to the inside of the wheel will be 12mm LESSThe outside edge of the wheel will EXTEND an extra 26mm I know I can go out with the tire some too, I just don't know how much. Quote Link to comment Share on other sites More sharing options...
Bartman Posted June 13, 2007 Share Posted June 13, 2007 Guy, Backspace is generally given in inches and offset in millimeters. Here's a chart that will help determine backspace from offset and vice versa: Of course there may be differences between my 240Z and your ZX, but based on what John Coffey posted on another thread an 8.5" wide wheel needs about 5" of backspace. Either there are problems with the chart or problems with your math. The 40 mm adapter and 42 mm offset give you a net offset of around 2 mm. According to the chart this would equate to a backspace of around 4". You came up this 90 mm which is closer to 3.5". BTW - I looked at my MM adapters this morning and they are closer to 25.4 mm (1") than 40 mm. Are your's custom, or are they different for a ZX? Quote Link to comment Share on other sites More sharing options...
80LS1T Posted June 14, 2007 Author Share Posted June 14, 2007 They are just their standard adapters? I assumed they were around 40mm, maybe I shouldn't have done that! LOL. I dont't have the car in my possesion at the moment so measuring them is out of the question. I will be investigate more once the car is back home. Guy Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.