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Discussion Starter · #1 ·
is there an easy to tell my actual speed (or closer to it than my speedo says) like a quick formula or something. i've got 31's and 3.73's. i know i could get a new speedo gear. but i'm too lazy for that
 

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Well if you have the stock speedo gear it should be a 36 tooth,(Mine was). I figured mine out by one of those speed signs with the radar gun attached that displays your speed. As far as a formula I don't know it. With 33's my speedo was off about 5 mph if that helps. When I was running 31's it was 1-3 off. Hope it helps some.
 

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Discussion Starter · #4 ·
thanks fellas, this is pretty much what i needed to know. i just wanted to be within 5mph of correct. but if it already is thats cool
 

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Pushy, Loudmouthed, and Ballsy
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Just for future reference, here's how I figured mine out. Drive on the highway that has mile markers every mile. Drive for about 20-30 miles to get a good representation. Compare your trip odometer (which you reset to start) to the actual miles you drove according to the mile markers. the ratio will tell you what percentage you are off by.
 

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WINNAR!!!!!!
2018 JLUR on tons and 40's.
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or you can figure it out by time. It should take you exactly 60 seconds to drive one mile.
 

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Pushy, Loudmouthed, and Ballsy
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or you can figure it out by time. It should take you exactly 60 seconds to drive one mile.
As long as you are going exactly 60 mph! Using the trip odometer and mile markers you can travel at any speed.
 

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Discussion Starter · #10 ·
the only problem goin by time is timing yourself that exact, and paying attention to the road and mile markers
 

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well i was gonna say you could set the cruise control to exactly sixty and then just hit the button on a stop watch but i don't think YJ's have cruise control
 

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Ya can have a friend clock you on the highway, 2way radios help greatly. Im running 31s and 307s, Im off by 5 at 70.
 

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I would try to find someone that would clock you. My brother in law is a state trooper so I am gonna have him clock me so I know how bad off mine is.
 

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I have a hand held I can bring home sometime if you need me to. Just let me know a few days ahead. It just plugs into cig. lighter.
 

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wonder if I could just drive over my chrono. Think it'd give me fps?
 

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J Who is your B-in-law? Is he at post3 B.G.?
He's Brooks he's with the columbia post I think, Metcalfe and Monroe. I am sure you probably know him, he was Glasgow PD before he became a trooper, and he's in the 623rd out of t'ville.
 

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is there an easy to tell my actual speed (or closer to it than my speedo says) like a quick formula or something. i've got 31's and 3.73's. i know i could get a new speedo gear. but i'm too lazy for that
A bit of a math nut here and was curious with my own 31" tires since I was passing everyone. I have a spreadsheet with the difference, but the file is too large to attach. If someone could help me I can provide the difference for sizes 28" - 32" based on 27" being the standard.
Thanks
 
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