What offset is correct?
12-20-05, 10:23 PM
#1
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What offset is correct?
I got my Forgeline 18X12.5 on the rear and 18X9 on the front but Forgeline screwed and forgot to open up the center hole to the right size. Besides that, I am worried that I also got the wrong offset.
What would be the correct offset for those wheels?
What would be the correct offset for those wheels?
12-21-05, 01:27 AM
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Assume you have a widebody or fender flares? How much wider is your rear? To clear the rear suspension with 12.5" wide wheels, you would need an offset of approximately +12 or less. With the 9" fronts, you would want a +45 to +50 offset.
BTW, since Forgelines are custom wheels, didn't you have to give them specific offsets to even order them?
BTW, since Forgelines are custom wheels, didn't you have to give them specific offsets to even order them?
12-21-05, 02:45 AM
#3
Ya what ryn said. How did you guys come up with the fitment. The centerbore should be a 67.1, the offset has to be determined by the body mods you surely have done.
50mm rears, and stock fronts are possible with those widths as Ryn has implied.
Rishie
50mm rears, and stock fronts are possible with those widths as Ryn has implied.
Rishie
12-21-05, 03:02 AM
#4
Measure the backspacing on the rears (distance between wheel pad plane and rim edge plane - don't use a round pole like my pic 
):
Anything more than 7.75" probably won't fit. 7.5" is good. My guess is that an offset around +19 would put you in the ballpark.
(Note that it is easy to miscalculate a conversion between the bacspacing and offset. The reason is that an 18x12.5" wheel IS NOT 12.5" wide from rim edge to rim edge. It is probably about 13.5" +/- 0.5" wide [but you MUST measure it if you want to do precise calcs!].)
I would tell Forgeline that you want 7.5" of backspacing. That is really what matters for clearing the suspension, and you will likely want as little clearance as possible for best performance (i.e. you wouldn't choose to have 2" of clearance to the suspension).
-Max
):Anything more than 7.75" probably won't fit. 7.5" is good. My guess is that an offset around +19 would put you in the ballpark.
(Note that it is easy to miscalculate a conversion between the bacspacing and offset. The reason is that an 18x12.5" wheel IS NOT 12.5" wide from rim edge to rim edge. It is probably about 13.5" +/- 0.5" wide [but you MUST measure it if you want to do precise calcs!].)
I would tell Forgeline that you want 7.5" of backspacing. That is really what matters for clearing the suspension, and you will likely want as little clearance as possible for best performance (i.e. you wouldn't choose to have 2" of clearance to the suspension).
-Max
Last edited by maxcooper; 12-21-05 at 03:22 AM.
12-21-05, 10:12 PM
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I am boring the wheels as we speak to 67.1 mm exactly. I ordered them through Pettit Racing and yes, I have their flares being molded after I get the wheels back from the shop.
WHat happened was that they confused the meassurements and used a Supra diameter which is 60mm.
I will pick the wheels up tomorrow and test fit them, but I am sure they will fit this time.
WHat happened was that they confused the meassurements and used a Supra diameter which is 60mm.
I will pick the wheels up tomorrow and test fit them, but I am sure they will fit this time.
