Author Topic: Speedometer  (Read 1245 times)

jacmac

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Speedometer
« on: March 14, 2011, 11:46:33 PM »
What would be the difference in the speedometer reading going from a 307 to a 355 rear axle ratio??
69 Z10,72 corvette

bertfam

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Re: Speedometer
« Reply #1 on: March 15, 2011, 03:03:33 AM »
Too many variables. You need to know the tire diameter, the RPM's you going and the gearing of the transmission. HERE'S a nice little calculator you can use that'll give you several readings with different ratios.

Ed

9T4Z

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Re: Speedometer
« Reply #2 on: March 15, 2011, 11:37:07 AM »
.305/.357 = .85  If my high school math still works your speedo will read about 15% lower.
Gary 9T4Z

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jacmac

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Re: Speedometer
« Reply #3 on: March 15, 2011, 11:38:26 PM »
Thanks for the help guys.Ill figure it out!
69 Z10,72 corvette

tom

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Re: Speedometer
« Reply #4 on: March 17, 2011, 01:54:27 AM »
Got a GPS ?  Go for a ride and see how far off you are. My old Honda read about 10% slow after I changed the tires. Never fixed it, as it was easy math.
69 X11 Z21 L14 glide
looking for a 69 export model (KPH) speed
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