recalibrating for gears

['94firebirdv6]

My car is in the shop now. I am hopefully getting it back tomorrow complete with 3.73s and LSD

I am wondering how much my speedo will be off. I need to get my PCM flashed for 3.73s how do i do this? i dont know if my local dealership would flash my pcm for a Y87 vin # but that will only be for 3.42s right? i also dont want to have to pay for something i'll only use 1 time
i dont like the idea of not knowing how fast im going but most of all, logging false mileage on my odometer.

[RallyRed 98]

don't get your pcm reflashed. i'm not even sure you'll be able to with a '94.

either get hypertech, slp recalibrator, or other... but until you get one of those, divide your current ratio by 3.73 to get the percentage over actual. if i recall, the difference between 3.23 and 3.73 is about 14%.

[00firebird]

so technically if you recallibrate your car for like really low gears (or would it be high), you can get more miles out of the odometer [img]smile.gif[/img]

[FunkZ]

Yes, if you program the computer that you have a numerically higher gear ratio (than you actually have), you will put less mileage on the odometer, but your speedometer will read low.

How to fix your speedo? Find a working used Hypertech (good luck) use a speedo recalibrator ($100) or send the PCM to Fastchip for reprogramming ($300)

Don't get the speedo recalibrator if you want to use your cruise control.

[1DangerousV6]

when i went to the new 155mph gauge face i used the yellow box speedo recalibrator..works great ..but yes it does disable the cruise control..when i went from 3.08s to 3.42s i just used HP Tuners to recalibrate [img]smile.gif[/img]

['94firebirdv6]

i dont have cruise control so that isnt a factor
like i said i cant justify spending $100 on somethin i will only use once but my speedo being off is gonna drive me crazy till i get it fixed

[RallyRed 98]

well, you can either do that or pay a dealership about that much and get it done once... that is, if they CAN do it, and only for a 3.42 ratio.

or you can do it the right way and be able to change to practically whatever ratio you want, be it up or down.