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-   -   The speedometer calibration on the Superchips programmers suck (

Thracks 10-12-2011 02:01 PM

The speedometer calibration on the Superchips programmers suck
'Nuff said.

Even with the proper measurement entered, it took a lot of guesswork and trial and error to get the speedometer reading perfectly with my navigator.

Just a message to anyone who might be thinking of buying a Superchips programmer for that reason. You can recalibrate your speedometer, but it wont be easy!

rics1997 10-12-2011 03:18 PM

It's no difference with any other programmer. You are only changing numbers preset in the Jeeps ECU. The problem isn't the programmer, it's the fact that tire sizes are not always what they say they are and compression from the vehicles weight and PSI of the tire play such a huge variation. Just think if you don't have GPS and just have to guess. All you can do is hope there is one of those portable radar detectors that the police set up on the side of the road is somewhere close, lol. The best start is always 1" less then the tire size and .25 either way should get you close if 1" isn't right.

DM6156 10-12-2011 03:25 PM

I used superchips on my old trucks, never had issues with any of the adjustments, but, I also measured my tires with a tape measure to get the correct size not just do the math based on the tire size.

If you do research on tires, you'll see that sometimes different manufactures tires have different revolutions per mile and different outside diameters even though they are the same tire size.

- Dan M

rics1997 10-12-2011 03:32 PM

Also you want to measure the tire with full weight on the tires from the bottom to the center of the wheel. Center to top or sides will not account for compression

bo9roadking 10-13-2011 10:00 PM

I've never used the Superchips programmer, but I recently used a ProCal and it worked like a charm. I measured the height of the tire to the nearest quarter inch, set a couple of dipswitch settings on the ProCal, plugged the ProCal into the Jeep, and waited for the horn to sound telling me that everything was set. The whole process took less than 5 minutes.

Also, what everyone else is saying about tire size is true. I installed 35" tires and they only measure 34". If you don't measure the tire and only go by the manufacturer's size, that could throw off the speedometer when it gets programmed.

Karvaster 06-05-2016 11:43 AM

Im new to the forum and this is my first post. I bought 33s for my jeep they measure 32 on the jeep. When i set the superchip to 32 the speed says im doing 70mph-ish when my 2 gps devices say im doing 65mph. So i changed it to 31s and im about .5mph off. what i dont like is the shift points and rpm seem better when i had it set at 32in. Anyone else notice this sort of thing? Am i hurting my drivetrain by going with the smaller size just to get the speedo right rather than the 32in? Thanks!

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