In a post last June, Jackson Zimmermann wrote that he thought that the
overdrive ratio of 5th gear is 0.82:1.
That lets you calculate how much change you will get with your
existing rear end, since the ratio of the stock 4th gear is of course 1:1.
5000rpm * .82 = 4100rpm
In a couple of days I can hopefully tell you first hand :-)
Ulix
Does anyone know the 5th ratio for sure? My #$^&@ Datsun Chilton manual
doesn't say.
On Wed, 26 Mar 1997 DANMAS@aol.com wrote:
> In a message dated 97-03-26 21:55:36 EST, you write:
>
> << Specifically, what kind of MPH per 1000
> RPM in 5th. >>
>
> To find the MPH per 1000 RPM, Multiply your tire diameter in inches by 2.975,
> and divide that by the rear end ratio times the 5th gear ratio.
>
> 2.975 X tire diameter
> ---------------------------------------
> rear ratio X 5th ratio
>
> Actually, this works for any gear ratio, just substitute 1st, 2nd, 3rd, 4th,
> for 5th.
>
> The 2.975 is what you get when you convert inches to feet to miles, and
> minutes to hours, and factor in the value of pi.
>
> To get your tire diameter, (2 X tire size X aspect ratio)/25.4 + wheel
> diameter.
>
> example: 2 X 195 X .70)/ 25.4 + 14 = 24.7" ( for a 195R70-14 tire)
>
> Try it, it works!
>
> Dan Masters,
> Alcoa, TN
>
Ulix __/__,__
.......................................................... (_o____o_).....
'67 Sprite
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