Rough Country Speedometer Calibrator

Rough Country isn't exactly known for top tier quality.

 

it's a wheel speed sensor regardless of transmission.

 

Are you sure of that? How do you know?

 

Prove it. Go unplug all 4 then go for a ride and see what happens

 

So I just chatted with a RC “live chat” and it says it uses GPS to calibrate it

 

Yup . Open this link . It’s in the notes. https://www.roughcountry.com/speedometer-calibrator-90043.html

 

What were they originally thinking you were inquiring about? Hahaha oh boy

 

I trust nothing from them.

 

Oops, my mistake. It's the HyperTech that is certified 50-state legal.

 

Really? My hypertech was not available to purchase in CA.. at least when I purchased it

 

Wheel speed sensors are thrown out of whack by larger tires. They count revolutions of a wheel of the outer diameter they expect (stock size tires), and use that the interpret speed. If you put a larger tire in you will have less revolutions over the same distance, so the wheel speed sensors that feed data to the ECU will feed it incorrect data regarding vehicle speed.

Whether or not this is part of the shift-point calculation by the ECU is unknown to me, but the data coming off the wheel speed sensors on a truck with larger tires than stock will be scewed.

 

I’m thinking it does not change the ecu data. But I’ll likely buy one and log it with techstream.

I’ve been wanting to adjust my speedo for a long time.

I’ll just blast them online for false advertising

 

They shipped it to my door. Says right on the box "Emissions certified 50-state legal" (for what that's worth...). The Air Resources Board may disagree.

 

correct - not arguing that.

 

Anyone with some reviews or feedback on this unit?

 

Some of you are ignoring the facts:

 

I hooked mine up today. Will be posting shots of techstream next to gps data.

 

Could you take shots of techstream veh speed PID as compared to cluster before the install ? <NVM, just re-read your post and you've already installed the sucker.
I mean, I'm interested to see how accurate the speed calibrator is compared with GPS as well, but I suspect there will be a small difference in any case.

There are some on TW that insist that the speed signal from the wheel sensors goes to the ECM first, and that any calibrator device will just change what the cluster shows. According to the SM, that's just not true.

Edit: Without knowing exactly how the hypertech or rough country units connect behind the dash, I cannot say 100% if they will affect the signal that ends up going to the ECM as well as what you see on the cluster. Logically speaking, I can't see where the two being different values would be a good idea. I CAN say that the speed signal (stock) definitely passes THROUGH the cluster before it hits the ECM.