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Gear Ratio Formula?

To: <land-speed@autox.team.net>
Subject: Gear Ratio Formula?
From: "Mike Meierle" <mike.meierle@alcatel.com>
Date: Thu, 25 Mar 2004 10:14:35 -0800
I have the standard formula below.....

mph = rpm x tire diameter / differential gear ratio x 336
76.468 = 4000 X 27.106 /4.22 X 336

Can I simply add on to this formula for calculating speed in specific gears
of the transmission by doing the following:

mph = rpm x tire diameter / differential gear ratio x 336/transmission gear
ratio

20.556 = 4000 X 27.106 / 4.22 X 336/3.72<- First Gear
34.758 = 4000 X 27.106 / 4.22 X 336/2.2<- Second Gear
50.979 = 4000 X 27.106 / 4.22 X 336/1.5<- Third Gear
76.468 = 4000 X 27.106 / 4.22 X 336/1.0<- Fourth Gear
96.795 = 4000 X 27.106 / 4.22 X 336/0.79<- Fifth Gear

Or do I need a Math refresher?  Mayf you out there?

Oh yeah, I'm building a Speed Table in Excel which incorporates the Tire
Diameter Calculator
slap in the basics, P205R75/15, and you get your speed at RPM and Gear.


Mike Meierle
36 Technology Drive
Suite #110
Irvine, CA 932647
Phone: (949) 450-9160 X8031
www.alcatel.com






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