Speedometer recalibration info

Predator support for GM diesel vehicles

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edon
Posts: 8
Joined: Sun Nov 14, 2010 9:32 pm

Speedometer recalibration info

Post by edon »

From various posts here, I found I wasn't alone having problems getting my speedometer to read correctly. Differences in tire's actual size to labeled size, rim width, air pressure, etc. all seem to come into play. What worked for me was to actually input "rolling diameter" instead of actual height of tire. Just measure rolling radius (from ground to center of wheel, vehicle sitting on ground) and double that reading. Entering your calculated value into the DS for tire height should get you going the proper speed.
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rydnhi4x4
Posts: 272
Joined: Tue Mar 13, 2007 10:22 pm

RE: Speedometer recalibration info

Post by rydnhi4x4 »

Nice info, thanks for the heads up.
http://www.thetruckstop.us
07 - CHEVY LBZ DURAMAX
All-Terrain T/A® KO - 295 75R16,
DYNOED ON 20 July 08 WITH -
PREDATOR SET ON THE 85HP TUNE / 423 RWHP - 709 FT/LBS
PREDATOR SET ON THE 120HP TUNE / 458 RWHP - 754 FT/LBS
bigdawg04
Posts: 91
Joined: Sat May 17, 2008 3:36 pm

RE: Speedometer recalibration info

Post by bigdawg04 »

Also a Garmin works great. Adjust until you are on the money with a Garmin
2007 Gmc Duramax Allison 2500HD 4 wd 4 Door
Blocked and Fingered
Predator u7186
S & B Cold Air Intake
Damon
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rydnhi4x4
Posts: 272
Joined: Tue Mar 13, 2007 10:22 pm

RE: Speedometer recalibration info

Post by rydnhi4x4 »

Garmin works, but I think the way Edon did it gets you way closer for the first time user.
http://www.thetruckstop.us
07 - CHEVY LBZ DURAMAX
All-Terrain T/A® KO - 295 75R16,
DYNOED ON 20 July 08 WITH -
PREDATOR SET ON THE 85HP TUNE / 423 RWHP - 709 FT/LBS
PREDATOR SET ON THE 120HP TUNE / 458 RWHP - 754 FT/LBS
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