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Author Topic:   3 spd standard
posted February 11, 2003 09:38 PM
Does anyone know where I can get info on gm 3spd manual tansmissions. I need to know the gear ratios and what to look for! We think we have a "189" trans and are running 2nd gear on a 1/3 mile clay track. It works good but we want more!! Thanks in advance!

posted February 11, 2003 11:54 PM
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posted February 12, 2003 09:57 PM
For second gear ratios in a 3spd saginaw I have found 1.50,1.68,1.81, I run a 4spd saginaw 2nd gear is a little deeper,2.02,and 2.20 are common.
Multiply your tranny ratio X rear end = Final drive ratio(use the tranny ratio for the gear you are running)

RPM=(MPH X Final Gear Ratio X 336)Divided by Tire diameter,(in inches)

Ratio= (RPM X Tire dia.)Divided by(MPH X 336)
These are cool, I run 2.02 tranny and 3.42 rear=6.90. So at 70 MPH X 6.90 X 336 Divided by 27 "Tires,= 6010 RPM.
Write these in your Chassis Documents, There invaluable, You can figure a tire change outcome before you even do it. Good luck.

posted February 12, 2003 11:58 PM
Thanks people! That is awsome information!!

Nothing is foolproof to a talented fool!

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