yourmom6990

ok, so i just figured out when i got my car a few months ago, the guy had 4.10 gears in it. when he sold it to me, he took the 4.10's out, but never recalibrated the spedo and rpm's back to the normal 3.27's. i did that trick with the digital display how it shows your mph and rpm's to the decimal, and its off by a good 7mph and 300rpms. is there anyway to fix this without buying a handheld tuner? and please dont tell me to just throw 4.10's in there to solve the problem, because ill be going with 3.73's andyway.lol.

sprostang

Look on the trans by the shifter. There is probably a speedcal there. It looks like a little black box. Anyway, when you do your gear swap, why not get 4.10`s??

Click this link. Hope it helps....... http://dallasmustang.com/page/speedcal.inst.php

wwmost

yea the only way ur speedo would be ready different is with a speedcal if you dotn have a tuner. take off the panel around ur shifter and look in there and see if you see a box.

domesticlover

ps, its actually count your miles slower than your actually putting them on. its counting 3.27 times around for every 4.10, so your actually making money. its not good but it is for you lol

silverstang1996

yeah why not 4.10s over 3.73s? i already had 3.73's in my car otherwise i might of gotten 4.10s. if you do highway driving i could understand tho cause mine runs at like 2500 or a tad bit less and it's just droning, so it'd be worse w/ 4.10s i'd imagine

Sicx13

the speed cal adjusts by the gear ratio. how would i adjust my speedo for diiferent size tires. i have 20s and my speedo is off around 4 Mph

cliffyk

For fine tweaking you need a tuner (handheld or a fixed tune) to adjust the tire's "revolutions per mile" value.[/align][/align]For the original poster,[/align][/align]The "digital trick" if just showing you the difference betwen the digital counter in the PCM and the analog gauge display, they both use the same source and PCM setup... [/align][/align]At what speed, and in what gear did you observe the 7 mph/300 rpm difference?[/align]

teos03centennialgt

Yeah how could you tell the difference?

yourmom6990

like i said i did the digital trick, and i drove and the spedo said "50" when the digital display read "43-44ish"

sprostang

Well, did you find the speedcal ??