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Speed?

cbbr

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Just lifted the 'Burb. How do I correct the speedometer or is there a calculator to tell me how fast I am really going. Went from 30" stock tires to 35" BFG AT's (34.5").
 
If you have a tachometer you can use that as your speedo. Just enter your data in the calculator for your setup and get the RPM's for different speeds in different gears. That is how I know how fast I am going. If you have an auto tranny then your numbers will be a little off due to torque converter slip.

If you have a 700R4 though in OD you should have no slip as long as the torque converter is locking up like it should.

Harley
 
You can do it yourself. This site shows you how... http://614streets.com/drac.html I did not use this site, but i did the same thing for my 1990 blazer about a month ago. I used a site made by a member here...K5Chris, but it looks like his is down, maybe PM him? He had really detailed info on how to do it.
 
Naturally nothing useful like a Tach. I'm just going to have to estimate for a while - and not pass people on the highway.
 
if you look around in the junkyard, some chevy trucks have a little gear reducer box- between the end of the speedo cable and where it hooks into the tranny or transfer case.
my speedo was off and i found a couple of these things in the junkyard... and one of them makes my speedo just about dead on.
 
Ryan B. said:
if you look around in the junkyard, some chevy trucks have a little gear reducer box- between the end of the speedo cable and where it hooks into the tranny or transfer case.
my speedo was off and i found a couple of these things in the junkyard... and one of them makes my speedo just about dead on.
Thats what those boxes are!!

I remember stepping up to 35's from stock 55mph being close to 70....a GPS is definately a good companion
 

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