speedo code
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Posting Guru
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speedo code
I'm not sure if I did my math right, but my stock setup was 3.08s. I added 33" tires and 3.55s. If my math is right which isa stretch at times, I'm thinking my speedo should be close to correct. If not,what code should I be using?
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Joined: Jan 2004
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From: Charlestown, RI
The speed is read as a signal off of the ABS sensor in the rear diff housing, and a tone ring that's bolted to the ring gear. It's based on tire revolutions.
The only time you'd need to change the constant is for a tire size other than what the truck came with from the factory.
The only time you'd need to change the constant is for a tire size other than what the truck came with from the factory.
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
You need to know your wheel size when it came from the factory so you that you will know the number of teeth of your tone ring.
Example 15" would be 108.
16" would be 120.
Then you would go to the tire makers web site to find the revs per mile of the tires you bought.
Then the math is:
Conversion constant= (Revs per mile) * (number of teeth of tone ring) / 8000
Example 15" would be 108.
16" would be 120.
Then you would go to the tire makers web site to find the revs per mile of the tires you bought.
Then the math is:
Conversion constant= (Revs per mile) * (number of teeth of tone ring) / 8000
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Thread Starter
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Posting Guru
Joined: Mar 2013
Posts: 1,726
Likes: 3
You need to know your wheel size when it came from the factory so you that you will know the number of teeth of your tone ring.
Example 15" would be 108.
16" would be 120.
Then you would go to the tire makers web site to find the revs per mile of the tires you bought.
Then the math is:
Conversion constant= (Revs per mile) * (number of teeth of tone ring) / 8000
Example 15" would be 108.
16" would be 120.
Then you would go to the tire makers web site to find the revs per mile of the tires you bought.
Then the math is:
Conversion constant= (Revs per mile) * (number of teeth of tone ring) / 8000
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