speedometer adjustment

born2saw · 10-17-02, 11:15 PM

I have a 1975 roadster (which was purchased very recently), L48, 4 spd that is nearly all original. I was reading in resonses to a tire question about adjusting the speedometer when changing tire sizes. My speedometer reads about 10 -15 mph faster than my actual speed (makes me feel like I am really going fast until a Kia passes me). I have P225R70 15 tires on stock rally wheels. Is there an way to adjust the speedometer without altering the originality of my car??

Thanks in advance for any suggestions.

10-17-02, 11:30 PM

Maybe the speedometer gear in the trans doesn't match your rear end ratio.You say 10-15 mph faster reading but at what true road speed. This way you can calculate your % error and buy a new speedo gear with that % of reduction. You need to first know your rear ratio and speedo gear ratio.

Yoda · 10-17-02, 11:32 PM

This subject comes up from time to time and one of the best threads on this subject is Right HERE. Take a couple of minutes and take a look and I think you will be heading in the right direction

At the Right Speed

We offer a lot of "Corvette Related Stuff/Information" here at CACC. Try to set aside some time.. yea I know like we all have extra time... to scout the place out, you'll be amazed at everything inside our walls here

Welcome aboard and Enjoy the Ride!