Speedometer Calibration With Larger / Bigger Tires?

[Osco]

Have you thought about teaching math, physics or engineering?

Wouldn’t work, this brain has three types of ADHD and a stupid high IQ.
Intelligence means nothing when you can’t stay on track. Useless numbers, stats and charts are like puzzles to me. It’s an obsession, I gotta know.
I do well to remember to put pants on.
And they gave me a commercial drivers license oh my.
:,P

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[rdc17]

I tried again, with Forscan 2.3.44. I am now able to write to the BCM.

However, after turning the car off and back on, a 4WD Fault error comes up in the instrument cluster. In Forscan I can see the P160 DTC for TCM, PCM, and AWD systems. I do not have the option to relearn the PCM and TCM (and AWD) systems like the tutorial has.

Changing the tire size back to the original, and clearing the DTCs got rid of the error.

 

[MKohlman]

I tried again, with Forscan 2.3.44. I am now able to write to the BCM.

However, after turning the car off and back on, a 4WD Fault error comes up in the instrument cluster. In Forscan I can see the P160 DTC for TCM, PCM, and AWD systems. I do not have the option to relearn the PCM and TCM (and AWD) systems like the tutorial has.

Changing the tire size back to the original, and clearing the DTCs got rid of the error.

I was actually curious if anyone had tested a BCM write with the 2.3.44 version yet. Thanks for confirming.

Unfortunately my Badlands and I are separated until Christmas (new job in CA and it is really my wife's ride so it is still in the Midwest) so I can't do much testing right now ?

 

[rdc17]

I was actually curious if anyone had tested a BCM write with the 2.3.44 version yet. Thanks for confirming.

Unfortunately my Badlands and I are separated until Christmas (new job in CA and it is really my wife's ride so it is still in the Midwest) so I can't do much testing right now ?

Do you recall if you had the relearn functions as an option?

I'm using a Carista OBD2 bluetooth adapter and get a warning about it not being fully supported when I launch Forscan.

 

[Jrl]

From 225 65R17 to my new 235 65R17 per calculators I found through google at exactly 60 mph on the 225 I’ll be doing 61.1 on the 235. I looked up the 245 65R17 and it was I think 61.7 mph..
Not enough to worry with.
These small increases won’t mess up suspension geometry or cause antilock braking timing problems.
And should not increase strain on the suspension or throw off transmission gear ratios enough to cause problems.
I’m only going up to 235 because I’ve got the 1.5L engine and I don’t want to give up any acceleration rates from a stop.
I think my small increase adds 4 pounds to each tire as it is.
So 4 pounds each tire x 4
16 pounds of additional rotational mass has the same effect on acceleration and deceleration as 32 pounds of static ( unsprung ) mass.
https://www.broncosportforum.com/forum/threads/yokohama-geolandar-a-t-g015.4229/post-72625

Osco I have 235 /65/17 now on a first edition if I go to a 245 /70/17 do you with all your infinite wisdom think I could do this with out a lift .Given that the first edition has a built in lift ? Your thoughts if you would be so kind . Thanks. Jim Pittsburgh

 

[Osco]

Osco I have 235 /65/17 now on a first edition if I go to a 245 /70/17 do you with all your infinite wisdom think I could do this with out a lift .Given that the first edition has a built in lift ? Your thoughts if you would be so kind . Thanks. Jim Pittsburgh

I cannot advise from personal knowledge or personal experience on this.
But follow me a bit. Among the stock/not lifted/models we have some running stock from the factory 225’s and some running 235’s. Then IF I’m right we have some models with a slight stock lift ??
Am I right fellow Broncolians !!!
Speak up !
In these pages I’ve herd several state they now run 245’s with no additional lift….
So,
Do they run the 245 on vehicles like my BASE model ? OR,,, do they have a factory taller model ?
Is there such ????
My main unanswered question asked more than once in more than one thread stands….
Do the guys that mounted 245’s test for rubbing at FULL suspension compression AND all throughout the complete turning radius while still at full suspension crush ????
First thing I’d do is ask the Mo Co.
,
I hope my 2 cents enlightens you in some way ?
, read on to post # 23
This Is the way~~~~~~~~

 

[MKohlman]

Do you recall if you had the relearn functions as an option?

I'm using a Carista OBD2 bluetooth adapter and get a warning about it not being fully supported when I launch Forscan.

Nothing that I've changed so far on the Bronco Sport has needed a reset/relearn but like most everyone it wasn't possible to make changes to the BCM module until this latest version release. So most changes I have made so far have been to the APIM (aka Sync).

On my Fiesta ST I've done several things (including a full APIM replacement from MySync to Sync 3) and there have been a few times where I did indeed have to trigger a system "relearn" afterwards.

On the Fiesta ST (and other Ford models) it has been possible to change the tire diameter, but with the Bronco Sport being fairly new FORScan is still not 100% yet.

The ODB2 adapter I've been using for the last year or so is the OBDLink MX+, which is on FORScan's recommended list and works well with both my Microsoft Surface Pro and Samsung Galaxy Flip.

 

[Osco]

Jrl, my base was transformed going from my Factory 225’s to my current 235’s but I think 91.087% of this wonderful transformation has to do with the Yoko’s All terrain design over the Conti’s All season design.
Leaving about 2.88 percent of the change due to the increase in size.
The remaining percentile has to be my Warlock blood :’P

 

[Jrl]

Jrl, my base was transformed going from my Factory 225’s to my current 235’s but I think 91.087% of this wonderful transformation has to do with the Yoko’s All terrain design over the Conti’s All season design.
Leaving about 2.88 percent of the change due to the increase in size.
The remaining percentile has to be my Warlock blood :’P

Yes for sure on the 235 they are from factory 235/65/17 , on my first edition and they are falken wildpecks . I have seen in our forums that a few owners of base , and big bend have gone to 245 with no issues .Thanks for your insight .

 

[RSH]

Jrl,
I think 70 series tires would be too tall without a lift and will have rubbing issues.
The overall diameter difference is 1.5" (.75 per side) from what you currently have, you may also have to do some trimming.
Check fordrangerlifts, they say 245/70/17 is the max tire size.
When making large tire diameter changes you affect drivability. Acceleration, stopping, handling and crusing rpm will all take a hit.

 

[Osco]

Something to ponder.
One owner in here with a beautiful orange Badlands I think it was raised his to a Jeep level of I think he said 10.8” of ground clearance.
A combo of tires and lift…
I wonder, I’d like to see a comparison of His Stock track width and wheel base and his modified set up directly compared to the Jeep he spoke of, specifically the Jeep’s track width. I think it was the Famous Rubicon model.
Wonder if anyone could find the Center of Gravity height for our BS’s And the Rubicon.
Chasing anti sway bar rates would most likely be pointless even with the data of CG heights.
If I was to go ‘UP’ with a suspension lift, not that I need that, I’d want to look into width, wheel spacers. And would be concerned with changes in roll with the higher CG as I have so many curves up here.
~~~~~~~
Sorry my brain does this often.
My Sunday morning caffeine buzz is intense today~~~
Osco waves to the techno geeks:’D

 

[tburner]

Has anyone taken another stab at this? I'm curious if the relearn function has been added.

 

[mmazz71]

Has anyone taken another stab at this? I'm curious if the relearn function has been added.

I haven't seen any other info. My Ford dealer said they can't do it as of now. They were thinking that it could be done with an update. None so far so they advised me to get a tune done to change speedo.

 

[tburner]

I haven't seen any other info. My Ford dealer said they can't do it as of now. They were thinking that it could be done with an update. None so far so they advised me to get a tune done to change speedo.

The PCM relearn function was fixed about a year ago. You can successfully correct your tire circumference now.

 

[Discount Tire]

@tburner many forum members have gone with bigger tire and wheel packages and would benefit from this information to correct speedometer error. Do you know if this is something that can be done DIY or dealership only?

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