Bob Lang wrote:
> The stock gears (3.70) with stock tires (26.5 inches total height)
> gets you roughly 110 MPH top speed at 5500 in top-gear without
> overdrive. By way of reference, with 4.88 gears this equates to a
> lot lower number (under 100 for sure . . .)
Using the Kastner formula*, I get 117.2 mph with the 3.70 rear end at 5500
rpm, and 90.6 mph with the 4.88 (actually 4.875) gears, so your guesstimate
is pretty accurate (and may be more accurate in practice than the
"theoretical" results from the formula).
> If you shop around a bit, you can even find a 3.53
> (the TR6 PI gearset, and 2500 saloon if memeory serves).
I thought the Euro-spec cars had a 3.45 rear end ratio . . .
Jim Hill
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* The Kastner formula:
Miles per Hour =
(RPM * TireDiameterInInches * 0.002976) / ( RearEndGearRatio *
TransmissionGearRatio * OverdriveGearRatio)
Here (in a non-OD box) that works out to (5500 * 26.5 * 0.002976) / (3.70 *
1 * 1)
(The constant 0.002976 is simply a conversion factor to convert minutes to
hours, inches to miles, and to factor the value of pi into the equation.)
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