FordExcursions.com Forums
badassxcursion
 |
|
• chalfont, PA, USA |
|
• Registered on 5/16/2005 |
|
• 25 posts |
• 1
|
|
 Posted:5/31/2005 22:51 |
|
|
ok I have a o1 x with a 7.3 psd bullydog blah blah blah....I am not sure exactly how much lift I have(we built it our selves) but I run 37 inch parnelli jones for tires...how do I correct my speedo? I did find a thread on how to have the dealer do it on the computer but that is only for tires up-to 34 inches..any help??
p.s. I am extremely happy I found this website,it has been invaluable |
|
E. Long
 |
• Subscriber since 1/1/2001 |
|
• Atlanta, GA, USA |
|
• Registered on 1/23/2001 |
|
• 2,229 posts |
• 1
|
|
|
Posted:5/31/2005 23:34 |
|
|
| Quote: | ok I have a o1 x with a 7.3 psd bullydog blah blah blah....I am not sure exactly how much lift I have(we built it our selves) but I run 37 inch parnelli jones for tires...how do I correct my speedo? I did find a thread on how to have the dealer do it on the computer but that is only for tires up-to 34 inches..any help??
p.s. I am extremely happy I found this website,it has been invaluable |
FWIW (For What It's Worth), here's a link so you can get a general idea of what your actual speed is:
http://www.supermotors.org/vehicles/calculators/index.php#finding_rpm
The dealer will have to recalibrate your speedometer. From what I've read, I belive the computer is calibrated to your differential gearing. So you really won't recalibrate for the tire size, you'll "trick" the computer into thinking you've got a different set of gears. In your case, you'd probably tell your dealer to calibrate your computer for 4.35 gearing (judging by the above calculator link, .7 transmission ratio, and 30" stock tire diameter).
37" tires (in real life, 35" tall?), .7 trans ratio, 2000 rpm @ 70MPH would need to have 4.35 gearing to emulate factory RPMs with factory gears/tires.
Hope that helps. Play around with the calculator...it'll help you figure it out.
-Eric
'67 Galaxie 500 - 390 FE, .030" over, FE to AOD adapter, disc brake conversion. The Daily Driver.
'00 Excursion - 7.3L PSD, LANDYOT Gen-II Radius Rods, Factory Tech Valve Body, 200K+ miles and going |
|
binc
 |
|
• Blue Springs, MO, USA |
|
• Registered on 5/30/2005 |
|
• 3 posts |
• 1
|
|
|
Posted:6/2/2005 11:37 |
|
|
Another option, you can acquire one of the SuperChips tuners (or equivalent) which possess the ability to recalibrate speedos based upon different tire/wheel combinations. I, personally, have never used this feature, so cannot vouch for it's effectiveness, but it is a documented ability of the Tuner.
You also get the "Side benefit" of being able to tune the vehicle for towing or high-perf applications. (Of course, both of these two performance options require the use of Premium gas, so you can add yet another few dollars to your fill-up). Lastly, these modules aren't terribly cheap. The price just jumped another $100 in the last few months up to $399, but you might do better on E-Bay.
|
|
Doug Loper
 |
|
• Byron Center, MI, USA |
|
• Registered on 9/26/2003 |
|
• 114 posts |
|
|
|
|
Posted:6/2/2005 17:06 |
|
|
When I looked into getting Superchip Tuner, the one for the Excursion did not have the feature available to calibrate the speedo. Not sure why, when it is available for the SD. I personally used the Superlifts Truspeed Calibrator. It has a toggle to switch to two different tire sizes which works best for me to swap seasonal tires. Also a good idea if you decide to change tire sizes because you adjust it yourself using adjustment screw. I set mine using GPS and it is dead on. It is available at www.speedcalibrator.com or www.superlifts.com.
2000 X V-10
Mods: 6" Revtek lift
35" M/T Baja Claw Radials
16" x 10" Eagle Alloy Rims
Superlifts Truspeed Calibrator
Pioneer DVD surround sound system.
SilverStar 9007
Clear front corners. |
|
kiarasue
 |
|
• Enumclaw, WA, USA |
|
• Registered on 9/27/2005 |
|
• 81 posts |
|
|
|
 Posted:10/9/2005 01:14 |
|
|
|
I know its been awhile since this thread started but there isn't a speedo gear to change in theX. They have a transducer which works kind of like a CPS but doesn't fail as often. It cost me $40.00 at the stealership and I checked with a speedo shop and they were the same. |
|
|
|
