View single post by edward_davis
 Posted: 09-05-2006 06:05 pm
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edward_davis



Joined: 07-06-2005
Location: Eugene, Oregon USA
Posts: 162
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 Mike, if you have the stock 185/70HR13 tires, the circumference of the tire should be about 6 feet.  At 60 mph, you're going ~90 feet per second, which works out to about 900 rpm for the wheels.  With the stock axle ratio of 3.727:1 and the 1:1 top gear, the engine should be going about 3350 rpm at 60 mph.  The stock JH tach often has difficulty with rpms in the midrange, but ~300 rpm is good for 30 year old electronics.