 ET vs Backspacing, What the... |
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| Krieger |
 Oct 8 2024, 06:14 PM
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Advanced Member  Group: Members Posts: 4,847 Joined: 24-May 04 From: Santa Rosa CA Member No.: 2,104 Region Association: None 
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I am going to order some new wheels for my track car. 15 x 9. I understand backspacing. I think all 911 and 914/6 backspacing stock is 125mm. That is what I'd like. The manufacturer is listing three different ETs: 3mm, 10.6, 23.3. Which ET gives me the stock backspacing?
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| technicalninja |
Oct 9 2024, 09:18 AM
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Advanced Member Group: Members Posts: 2,531 Joined: 31-January 23 From: Granbury Texas Member No.: 27,135 Region Association: Southwest Region
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QUOTE(JamesM @ Oct 8 2024, 10:59 PM)  https://tiresize.com/wheel-offset-calculator/ https://tireswheelsdirect.com/wheel-offset-...ace-calculator/ QUOTE(SirAndy @ Oct 8 2024, 11:24 PM) Found this in the info listed on an online calculator. Not sure how accurate it is but it assumes that a 9" wheel is actually wider than 9" if you account for the wheel "lip". (IMG:style_emoticons/default/idea.gif) QUOTE Once you have your wheel width, it’s common practice to add an inch to it to account for the wheel’s outer lips before dividing it by two. Wheel width is supposed to be measured tire bead to tire bead. If you've got a 9" wheel it should be 9" between the beads, not total width of the wheel. JamesM's wheel calculators state the same thing. So, if you're close you should actually measure what you've got and NOT trust published widths. Some wheels have skinny lips, and some are fat. Adding an inch overall should be "safe" in most cases. |
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Posts in this topic
Krieger ET vs Backspacing Oct 8 2024, 06:14 PM
JamesM https://tiresize.com/wheel-offset-calculator/
htt... Oct 8 2024, 09:59 PM SirAndy
I am going to order some new wheels for my track ... Oct 8 2024, 10:05 PM SirAndy Found this in the info listed on an online calcula... Oct 8 2024, 10:24 PM sixnotfour A factory 15x9 is 3mm offset,and have a 117mm back... Oct 9 2024, 08:38 AM Krieger Thank you! So a 9" rim =228.6. 228.6/2... Oct 9 2024, 08:39 AM sixnotfour Backing the day you could buy a actual 245/50 -15 ... Oct 9 2024, 08:50 AM BillJ One of my combos is 15x9 and I used minilites from... Oct 9 2024, 10:16 AM
Olympic 914 This chart may be some help.
It is for 911 Fuchs ... Oct 10 2024, 08:03 AM |
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