confused.

[TXsilverado]

to make a long story shorter, allen was in houston a few months ago to do programs. when he plugged into mine he said that the computer was locked up so he couldnt touch it. the truck already had a program on it. i found the guy who programmed the computer and he is a mechanic for a dealorship around here.

i already knew the guy who programmed it so reflashing the pcm was suposed to be an easy and cheap job. when he went to reflash my current pcm it wouldnt let him touch it which would explain allen not being able to touch it. so he warrantied it out and put in a new one and updated it. after i got on the road it was pingin like a mofo at WOT and about 3 miles down the road the truck died on me. started it back up and it sputtered all the way to the shop needing a restart every once in a while. he poked around for a while then replaced that new pcm. now its runnin but still pings in the upper rpm's. now allen can finally program my pcm!

anyways when i asked if he needed the gear ratio for the pcm he said it was already set to whatever the vin said was in it. it wasnt a big deal to me since allen is suposed to crack into my pcm here soon but once i got on the road i noticed that @ 70mph i was still running the same exact rpm's ?? i was under the impression that it has 373 gears in it when i bought the truck,and that it was programmed for them. was it never programmed for 373's? and if it wasnt would that be why my truck would hit the rev limiter before shifting to 2nd?


anyways, now for trying to figure out what size gears i have out back. if i have 373 gears, 4l60e, and 245/70-17(30.5") tire running at 2000 rpm, how fast should i be going(im showing 70 with stock pcm). what about if i had a 342 rear end? my glove box says gu6 and thats a single track0 342 if im not mistaken. im positive its posi so i know the rear ends been broken open. does it sound like it was just never programmed for the 373's or do i still have 342's?

am i even going in the right direction to figuring out my gears??? thanks for any help you guys have for me

[vv8]

well in the sub with 3.73 at 80mph the rpms are at 2400 with 31.6 tires. hope this helps.

[white1]

I don't know if it helps, but I think the speedo is electronic, so your rpms, and speedometer will show the same as stock even with different gears or tire sizes until your pcm is corrected. Good luck getting everything straight.

[chrisj6]

The tire size will show the same as stock, the revs however will always be correct. It is just the speedo you are correcting with new gears and or tires.

Chris

[TXsilverado]

it has 3.73's with a stock 342 tune. got a friend to follow me on the frwy and while im bouncing off of my 100 speed limiter he was riding next to me at 80 mph

why am i pinging with a factory pcm??? will it stop after it has time to learn my motor or do i need to go ahead and up the octane on the next fill up?

[chrisj6]

Try filling up with a higher octane on the next fillup, or just put 93 in and let Allen tune ya up!

Chris