Has anybody had a problem getting thier speedometer to calibrate right after getting the gears changed? I just had my gears changed from 3.31 to 3.73 at least thats what I wanted and paid for and thats what was stamped on the gears but,when they (the dealership) recalibrated the speedo for 3.73 gears it was off by about 6 or 7 mph (to fast). The tech got his GPS unit and we went for a ride to check it to make sure and I was right. We ended up lying to the computer and calibrated it for a 3.55 gear. That got it to about 1 or 2 MPH off. Close enough but, that doesn't make sense either. If you go from a lower gear to a higher gear it takes more RPM's per MPH or am I wrong on that? Anyway just curious and if I get my own tuner I may have to know for sure about it.
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BLACK 2008 PREMIUM GT; INTERIOR UPGRADE PKG MODS(so far);DiabloSport Predator 3.73:1 GEARS ROUSH SHORT THROW SHIFTER SIDE WINDOW LOUVERS S&B INTAKE INTAKE MANIFOLD COVER 18x9" POLISHED BULLITT WHEELS GT500 STYLE SIDE SCOOPS
Posts: 11182
Joined: 9/16/2006 From: Fishers, IN Status: online
the dealership cant calibrate the gears in the factory tune as far as i know. No one has reported them saying they can atleast, all the dealers say no. You have to buy a handheld tuner and change them in the tune that way. You should get a cai and tune also, then just change the gear ratio in the tuner you get.
if you have $300+ then get a performance tuner. sct or predator, etc. along with a huge power boost you also input what gear you have and the speedo is fixed. its that easy except the $300. forget the dealership. their out to rape you. they wanted $630 labor to install my 4.30's. i had a local garage install for $260. grab a tune and be done. good luck.
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2006 GT Boy Racer Body Kit Cervini C-Series Hood w/ Roush Scoop Steeda CAI w/ Pro Flow Elbow SCT 93 Octane Tune Steeda Throttle Spacer Plate Steeda UDP 4.30 Gears SLP Loudmouth Exhaust Black Panther 330 20x9 Wheels Nitto 275/35/20
If and when you get a tuner with custom tunes, the vendor providing the tunes will set it up for your 3.73's. And once you have the tuner, you can reset it for tire size changes, too (amongst other things).
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Rick 07 GT Prem, Alloy, MT, 3.55s, Steeda CAI/Xcal2 w/Brenspeed tunes, 14" shorty, 275/40/18 Goodyear Eagle F1 Allseasons on SVT 2007 Cobras, FRPP Stingers
the guys at Ford told me that they didn't have the neccesary equipment to calibrate for 3.73s since they weren't a factory option for our cars. You will have to spring for a custom tune if you want to correct the problem.
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'05 Sonic Blue- Work in progress
quote:
(at 45) "I didn't always have a happy childhood, but I did have a long one"
I was standing right there when the tech changed the settings. It could have been his own personnal device. He had what looked like a PDA and hooked it up to a handheld diagnostic device that was plugged into the OBD port. It went through a series of menus for differant options.He selected the tire size and gear ratio then uploaded the program when it was done it said to turn the key off and on a few times and it was done. Does that sound like what you have to do with a tuner? The speedo is close enough now. Most of them are only good for +/- 3 mph anyway.
Yes I could have saved some money by going to some other shop but I don't know of any in this area that I would trust to do this plus I need to keep my warranty. If anything happens to the drivetrain they can't use this as an excuse to get out of fixing it.
I just bought a 2008 GT500 and had my gear ratio changed RE gear ratio changed to 3.73's. I had it changed before even picking up my car. They said it came with 3.55's, but everywhere I read it says they come 3.31 out of the factory. My speed was way out after driving away..I would say 25 KM/Hour out (Calgary Canada here!). I took it back and they said they recalibrated. It is still the same. I just did a test with my other Mustang and when it reads 8.3 KM for a trip the 2008 GT500, reads 9.5 KM. The SVT dealership in Calgary says they have never heard of this being an issue, but based on the comments on this forum it is an issue. wished these guys where I bought it would just come clean and say that they don't know what they are doing. I don't want to drive the thing until i get it fixed as it is racking up too many miles for the distance I am going! Should I tell them to fool the thing by saying I have 3.55's in there instead.
Regular Ford dealerships are so useless, they know every inch of the stock computer and should be able to make it do anything, take the car to a Ford Racing dealer, tell them you used FRPP gears and they should be able to update the stock calib, after all what are you going to do if you sell the car or trade in, give the dealer or person buying the handhel tuner, damn dealers, so full of
There are also some speedo dyno shops, I am sure they can re-calibrate speedometers all the time and must be able to change it on the stock tune, example: as a mother of 5 with a mini-van is probably not running a 93 octane tune with advance timing for a twin screw blower !!! So if she takes it to a speedo dyno shop , they run the numbers and find an issue they tweak it in the computer, am I wrong ?
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Wrong speedometer calibration? - 
RE: Wrong speedometer calibration? - 
