Speedo Recalibration question
Thread Starter
|
Cross-Country
Joined: Sep 2004
Posts: 55
Likes: 1
From: So Cal
Speedo Recalibration question
Hi All,
Yes, I did do a search on this and the Super Duty forum, and each time I begin to check the possible hits on the subject, the search engine keeps shutting down, and then pops up a window saying there were no matches?????
Anyway, I have a quick question for site members regarding the Superlift Tru-Speed in line recalibrator for the speedo. It seems like somewhere on this site, quite a while ago, I read about that unit causing many problems for the computer on our trucks. Does anyone here have any personal experience with the Tru-Speed calibrator, or know of any problems?
I really want to add one if the recommendations are good....
TIA,
JJ
Yes, I did do a search on this and the Super Duty forum, and each time I begin to check the possible hits on the subject, the search engine keeps shutting down, and then pops up a window saying there were no matches?????
Anyway, I have a quick question for site members regarding the Superlift Tru-Speed in line recalibrator for the speedo. It seems like somewhere on this site, quite a while ago, I read about that unit causing many problems for the computer on our trucks. Does anyone here have any personal experience with the Tru-Speed calibrator, or know of any problems?
I really want to add one if the recommendations are good....
TIA,
JJ
Postmaster
Joined: Jun 2004
Posts: 2,646
Likes: 1
From: Milky Way Galaxy
Originally Posted by wdglide
Some people say its a waste of money, but I'm still interested.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Actually, anything with an electronic tranny "should" be re-programmed for different tire sizes.
I'm assuming you are changing tire sizes... Otherwise, if you're just re-gearing, there is no recalibration required for gear changes.
The trick is, if you go big enough, you can't recalibrate the computer far enough and you need the "black box" to get the speedo correct.
I'm assuming you are changing tire sizes... Otherwise, if you're just re-gearing, there is no recalibration required for gear changes.
The trick is, if you go big enough, you can't recalibrate the computer far enough and you need the "black box" to get the speedo correct.
Elder User
Joined: Oct 2004
Posts: 626
Likes: 0
Originally Posted by krewat
Actually, anything with an electronic tranny "should" be re-programmed for different tire sizes.
I'm assuming you are changing tire sizes... Otherwise, if you're just re-gearing, there is no recalibration required for gear changes.
The trick is, if you go big enough, you can't recalibrate the computer far enough and you need the "black box" to get the speedo correct.
I'm assuming you are changing tire sizes... Otherwise, if you're just re-gearing, there is no recalibration required for gear changes.
The trick is, if you go big enough, you can't recalibrate the computer far enough and you need the "black box" to get the speedo correct.
Postmaster
Joined: Jun 2004
Posts: 2,646
Likes: 1
From: Milky Way Galaxy
Originally Posted by krewat
The trick is, if you go big enough, you can't recalibrate the computer far enough and you need the "black box" to get the speedo correct.
Trending Topics
Posting Guru
Joined: Jul 2005
Posts: 1,617
Likes: 4
From: Denver, Co
Originally Posted by texcan
That's right. Went to the dealer 3 times for a recalibration and they were having problems with their computer. Finally the dealer called ford & with the size tire I have they cannot recalibrate.
I've spent several years haunting the Dodge Dakota/Durango forums (Yeah, yeah...my dark days with a Dakota Quad Cab). So, I know a lot more about their setup than I do for the Super Duties, but in that world, what you needed was the "tire revolutions per mile" value for whatever brand, style & size of tire you have on your rig. This can be found pretty easily either from a tire shop or the tire manufacturer's website. That value can then be programmed into your rig to correct the speedometer, odometer, and ABS functionality--and that of dependent systems like MPG & distance to empty calculators.
I suppose there is the possibility that Ford hard-coded a set of specific tire sizes to an EEPROM within the computer and that the computer will only accept those specific values. But, I would tend to believe that the system is a little more flexible than that.
Can someone with one of the reprogrammers chime in with the valid range or specific values that are valid?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Laughing Gas
Joined: Dec 2005
Posts: 906
Likes: 107
From: Seattle area
The PCM can only go down to 600 revs per mile -- pretty close for 35s, right on for anything less than 34" -- thus, to really correct for larger tires that turn less than 600 revs per mile, you need the Tru-Speed. (Gearing doesn't matter -- the speed sensor picks up a tone ring on the rear ring gear, and counts axle revolutions AFTER the final gear reduction -- thus only tire size effects the signal)
Steve
Steve
Postmaster
Joined: Jun 2004
Posts: 2,646
Likes: 1
From: Milky Way Galaxy
That's not good if the PCM is limited to 600 Revs/mile. I'm about to put a set of 35" Super Swampers on the dually and they measured out to 587 rev/mile. I guess I'll be skipping the dealer re-program and going straight for the TruSpeed.
Laughing Gas
Joined: Dec 2005
Posts: 906
Likes: 107
From: Seattle area
With 35s I wouldn't sweat the Tru-speed. Just have the dealer recal to 600 rev/mile. The error is very small -- you'll be going maybe one-two mph faster than your speedo reads when at hwy speeds -- that's nearly within the readability of the speedo anyway. Spend the $200 on something better.
Steve
Steve
Senior User
Joined: Jul 2005
Posts: 151
Likes: 0
From: Surprise, AZ
Funny, I couldn't find this when I searched the other day. I emailed SCT about this and here are my replies. So who is correct? Or maybe I don't understand.
If you have a gear change, your speedometer would not be affected so I have to assume you have had a tire change. There is a product called “SpeedCal” that you can install in the vehicle that will take care of that. Tire changes will not affect the shifting, but gear changes might. You can correct for that however with a tune.
James
Your speedometer on that vehicle is controlled by the abs module which is why you cannot adjust for tire size in the tune. The nice thing about this is that your speedo will not be off due to gear changes.
James
If you have a gear change, your speedometer would not be affected so I have to assume you have had a tire change. There is a product called “SpeedCal” that you can install in the vehicle that will take care of that. Tire changes will not affect the shifting, but gear changes might. You can correct for that however with a tune.
James
Your speedometer on that vehicle is controlled by the abs module which is why you cannot adjust for tire size in the tune. The nice thing about this is that your speedo will not be off due to gear changes.
James
Last edited by AzBaddBoy; Mar 19, 2006 at 06:09 AM.
Junior User
Joined: Mar 2004
Posts: 99
Likes: 0
From: So. CAL
I have had the Superlift Tru-Speed sensor installed for a year or so now and I have not had any problems. You just dial it in with a GPS and tuck it in under the dash. It can be adjusted as needed for tire wear, or whenever you change tire sizes.