Re: Correct speedo gear

[Dave Casey <dcasey@xxxxxxxxxxxxx>]

With a 21 tooth gear, the cable will turn faster than with a 24 tooth gear,
thus the speedometer will read faster than you're actually going. Indicated
speed will then be about 24/21 = 1.14 times actual speed. So at 60mph on
your speedometer, you'll be doing around 52 on the road. This is where I got
the 8 mph, however, it would be more accurate to say that it will read 1.14
times too fast as at an indicated speed of 30, you'd be going 26, an error
of 4 mph. So, get a ratio adapter or velcro a calculator to your dash.

2(235 mm)(0.60) is the total sidewall height = 282 mm or 0.925 ft.
Rim diamter is 15 in or 1.25 ft.
Total tire diameter is 2.175 ft.
Circumference is (2.175 ft)*Pi = 6.834 ft.
Thus every time your tire rotates, the car moves that many feet.
This becomes 0.001294 mi/whee revolution, which when divided by 3.91 yields:
3.31E-4 (0.000331) mi/driveshaft revolution.

For your speedometer to register 60 mi/h, the cable must spin at 1000
rev/min which means that the cable should turn 1000 revolutions per mile.
The tailshaft on the '65 transmission has 8 teeth.
Let x = the number of teeth on the speedometer pinion.
8 / (x * 0.000331) = 1000, or x = 24.169 teeth. Thus for an accurate
speedometer he needs a 24 tooth pinion.

Dave Casey

----- Original Message -----
From: <Dodger7998@xxxxxxx>
To: <1962to1965mopars@xxxxxxxxxx>
Sent: Wednesday, March 24, 2004 4:20 PM
Subject: Re: Correct speedo gear


>
> In a message dated 3/24/2004 4:15:06 PM Central Standard Time,
> dcasey@xxxxxxxxxxxxx writes:
>
> > and your
> > speedometer will read about 8 mph faster than you're actually going.
> >
>
> I thilnk that you had better add a little more info here or I am going to
say
> that you have been relaxing in the sports bar to long
>
>                  dodger
>
> --
> [Non-text portions of this message have been removed]
>
> ----
> Please address private mail -- mail of interest to only one person --
directly to that person.  I.e., send parts/car transactions and negotiations
as well as other personal messages only to the intended recipient, not to
the Clubhouse public address. This practice will protect your privacy,
reduce the total volume of mail and fine tune the content signal to Mopar
topic.  Thanks!
>
> '62 to '65 Mopar Clubhouse Discussion Guidelines:
> http://www.1962to1965mopar.ornocar.org/mletiq.html.
>


----
Please address private mail -- mail of interest to only one person -- directly to that person.  I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic.  Thanks!

'62 to '65 Mopar Clubhouse Discussion Guidelines:
http://www.1962to1965mopar.ornocar.org/mletiq.html. 



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