Rough Country Speedometer Calibrator

Why my dealer keeps saying it can't be done. Any of you folks used this product?

https://theyotagarage.com/products/rough-country-speedometer-calibrator-2019-2023-toyota-4runner

 

But why?

 

I got 34 inch tires

 

This seems interesting. If you try it, make sure to share your thoughts on it. I wonder how much it affects shifting.

 

Very nice find.

Do some testing and let us know your results. Below is what I tested with my 32.76in 285/70R17 tires which I bet results of speed and mpg readout be different from 285/70R17s that are taller than 33inches.
(I might try to post a video on this test sometime just to share my results)




Also curious how tall are your 34in tires?

 

The thing is this little module has to stay always to trick the system.. It is not reprogramming the 4Runner computer

 

Junk Country.

 

Screw it, I am going with something like this

 

I run 285's and there was no speedo change in going with bigger tires. I go by a school everyday with a speed limit sign that shows your speed and the sign and my speedo are the same at different speeds i.e. 30-40-50mph.

 

How can be no change? Are you defying physics?

 

The stock speedo is set to read a little higher than actual. Jumping up to 285/70-17s will yield an indicated which is a little slower than actual. In my case it’s a little less than 1mph slower on the speedo than actual.

Your mileage will vary on 34s (lol, sorry). At your size correction would probably be more needed.

Have you posted pics your rig on 34s yet? How are you liking the bp-51s adjustables?

 

Not yet. Have appointment on Thursday. To be exact, my tires are 285/75/R17 KO2, something like 33.8 inches, so 34s lol.

 

So it has to stay connected all the time? To the computer directly, or the obd port?

Another option is to have it tuned. But that’s a more than twice as expensive.

 

Not sure. But it has be connected there all the time. I need to read their manual. You program the module on your computer for bigger tires and then connect the module to the 4Runner, the module needs power too.

 

Yeah it's an inline dongle plugged to the back of the gauge cluster. Commonly used on 3rd gen Tacomas with larger tires. Same unit as Hypertech but with RC branding. No experience with it on the 4R.

 

Rubs like crazy, haven't moved it for over a week. Turn radius is the size of Texas.

 

^Get to cutting

 

That's the plan. And more cutting when these tires wear out, to fit 35s. This truck got ruined anyways.

 

A tune can change the speedometer display scaling? Typically the tune needs tire size and gearing info because the tables are torque-based, but I thought that didn't change the gauge.

 

Tunes can’t adjust MPH? I figured they could, but maybe not it seems

How bad is the rubbing, and where?
@SlvrSlug I believe got 34s as well. I think he did pretty ok from what I recall, the usual front fenderliner trimming, not sure what else. How close to the body mount?

 

Doesn't even look lifted with 34s stuffed in.

 

He posted the lift is next thursday. At least at stock height, it’s pretty clear what will rub. With the lift, it might end up hiding a lot of that rub.

 

That makes sense. Kind of surprised it's driveable with the 34s no lift or trimming.