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Chart has been attached as a thumbnail image.
As you already know, I can't view thumbnails, but what I'm actually searching for is the stock offset for my 2014 20" R/T Shaker wheels. I'm looking at installing Forgestar CF5 18 x8.5 front wheels and 18 x 9.5 rear wheels. I need to know the correct offsets for front and rear to purchase them. Can you help?
 

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As you already know, I can't view thumbnails, but what I'm actually searching for is the stock offset for my 2014 20" R/T Shaker wheels. I'm looking at installing Forgestar CF5 18 x8.5 front wheels and 18 x 9.5 rear wheels. I need to know the correct offsets for front and rear to purchase them. Can you help?
I think that you have a 24 mm offset. The OEM 9" wheels on my 2009 SRT Challenger are 25 mm.
 

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Thanks Cuda for posting this chart.

I'm still researching my way through some custom wheels, and this will at least give me a grounding of data.

On my '15 Scat, with the factory 9" wheels, the backspace is 6", which according to this chart means I have an Offset of 25mm...which is in fact correct. What I'm working on now is calculating exactly how low I can go in terms of backspace for a wheel to fit over my front Brembos. I'm looking at a low backspace in order to create as much "dish" as possible....but more importantly, trying to calculate exactly what clearance I need, not just from the disc/caliper outward, but from the centerpoint of the wheel assembly radially outward...this will dictate the design of the wheel itself....

....of course, life keeps getting in the way, causing this project to advance in sporadic millimeters; the latest interruption is my having to tear out a ceiling to find a water leak....(sigh)
 

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Granted, the offset/backspace have an indirect influence on clearing the brake calipers, but it's the design of the wheels spokes that determines if they will clear the calipers.
You must either have wheel manufacturer confirm clearance of the specific calipers and/or know someone that has fit it on their car.
wheel_offset.jpg

Brake Clearance.jpg
Some wheel manufacturers will provide a form for you to fill out which includes requirement for caliper height and diameter.
 

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Thanks Cuda for posting this chart.

I'm still researching my way through some custom wheels, and this will at least give me a grounding of data.

On my '15 Scat, with the factory 9" wheels, the backspace is 6", which according to this chart means I have an Offset of 25mm...which is in fact correct. What I'm working on now is calculating exactly how low I can go in terms of backspace for a wheel to fit over my front Brembos. I'm looking at a low backspace in order to create as much "dish" as possible....but more importantly, trying to calculate exactly what clearance I need, not just from the disc/caliper outward, but from the centerpoint of the wheel assembly radially outward...this will dictate the design of the wheel itself....

....of course, life keeps getting in the way, causing this project to advance in sporadic millimeters; the latest interruption is my having to tear out a ceiling to find a water leak....(sigh)
As far as a water leak...assuming you have a toilet room above near by, I hope you looked at easier options first. Like checked toilet drain seal, or excess water spill onto floor of bathroom.
If you think it's not related to a bathroom, did you consider heating system? Or is rain water a possibility? Being a retired plumbing design engineer, and home owner for 50+ years I've seen them all.:smile:
 

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As far as a water leak...assuming you have a toilet room above near by, I hope you looked at easier options first. Like checked toilet drain seal, or excess water spill onto floor of bathroom.
If you think it's not related to a bathroom, did you consider heating system? Or is rain water a possibility? Being a retired plumbing design engineer, and home owner for 50+ years I've seen them all.:smile:
Not to derail the post...but thanks for the tips!

I've ruled out rain, and the heating system. Yes, I've checked the toilet; seated firmly with no wiggle, no water on floor, surrounding tiles not loose (indicating mastic loosened by water from wax ring). When water cut off to toilet, leak continued. I suspect a cracked pipe. I'm re-caulking the shower just in case. Part of the ceiling has to come out due to the water damage, so I'll use the opening created to try and determine exactly where the leak originated.
 

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As you already know, I can't view thumbnails, but what I'm actually searching for is the stock offset for my 2014 20" R/T Shaker wheels. I'm looking at installing Forgestar CF5 18 x8.5 front wheels and 18 x 9.5 rear wheels. I need to know the correct offsets for front and rear to purchase them. Can you help?
WheelStudio is a supporting vendor on here that handles Forgestar. They may be of some help to you.
http://www.challengertalk.com/forums/f213/wheelstudio-shipment-customer-day-showroom-563713/index12.html#post8215826
 

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I'm way ahead of you on that one. I already used their live chat feature to check everything out. The only problem is that most of these guys don't know much about Challenger wheel offset.
You would think that they would make it their business to know all that stuff.
Well it sounds like you got your help of either 24 or 25, as I recall. You could always look on the back side of you wheel to be sure.
Now if you were planning to increase your tire width beyond 275, then you may have to look closer to determine if stock offset is best for the wider width.
 

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As you already know, I can't view thumbnails, but what I'm actually searching for is the stock offset for my 2014 20" R/T Shaker wheels. I'm looking at installing Forgestar CF5 18 x8.5 front wheels and 18 x 9.5 rear wheels. I need to know the correct offsets for front and rear to purchase them. Can you help?


I think you’ll be safe between 18 to 24 mm. I’d go with 18mm that way if you decide to upgrade the knuckles and big brake kit you’ll be able to use the wheels.
I went with 16mm with my 18x9.5 on my SRT8.
And why not got with 9.5” all around?
 

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I think you’ll be safe between 18 to 24 mm. I’d go with 18mm that way if you decide to upgrade the knuckles and big brake kit you’ll be able to use the wheels.
I went with 16mm with my 18x9.5 on my SRT8.
And why not got with 9.5” all around?
Anywhere I can reduce weight I'm going to do it.. I'd install 18 x 8 wheels in front if Forgestar made them in CF5's.
 

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Granted, the offset/backspace have an indirect influence on clearing the brake calipers, but it's the design of the wheels spokes that determines if they will clear the calipers..
This is a smart man right here. So many in here make this mistake.
 
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