CRG Discussion Forum

Camaro Research Group Discussion => General Discussion => Topic started by: jacmac on March 14, 2011, 11:46:33 PM

Title: Speedometer
Post by: jacmac on March 14, 2011, 11:46:33 PM
What would be the difference in the speedometer reading going from a 307 to a 355 rear axle ratio??
Title: Re: Speedometer
Post by: bertfam on March 15, 2011, 03:03:33 AM
Too many variables. You need to know the tire diameter, the RPM's you going and the gearing of the transmission. HERE'S (http://www.angelfire.com/fl/procrastination/rear.html) a nice little calculator you can use that'll give you several readings with different ratios.

Ed
Title: Re: Speedometer
Post by: 9T4Z on March 15, 2011, 11:37:07 AM
.305/.357 = .85  If my high school math still works your speedo will read about 15% lower.
Title: Re: Speedometer
Post by: jacmac on March 15, 2011, 11:38:26 PM
Thanks for the help guys.Ill figure it out!
Title: Re: Speedometer
Post by: tom on March 17, 2011, 01:54:27 AM
Got a GPS ?  Go for a ride and see how far off you are. My old Honda read about 10% slow after I changed the tires. Never fixed it, as it was easy math.