gears and pcm

[hawgs]

so i used to have an open 3.08 rear end, i recently swapped them out with LSD and 3.42s, and i know a few people at the local chevy dealership and they said they can get my pcm reprogrammed no problem. day after i got gears installed i went to the dealership and they had all kinds of trouble trying to do it. i brought them a vin number i found off this site to use, but they said they didnt need it they could use mine and all they have to do is call someone from GM and they would give them the correct codes to reprogam it for gears and bigger tires (275 17s.. i know theres no difference hardly from stock tires but they wanted to reprogram it for these too). so they call this guy and he wasnt there and so they told me to come back in about two hours, i come back and they tell me that the guy said that those gears are too big for my car and the tires are too big as well. so all that sucks, anyone know how to do this so i can tell them?

what all do gears effect? i know it will make speedo fast, will it also throw off shift points? i went to the track tonight and it was f*cking pathetic the times i got... it feels like it is shifting way early and when i cruise beside people in my club with 3.42s i shift a lot sooner then they do. i hope that i can get it reprogrammed and it will fix it because i am terribly unhappy with times compared to 3.08s

[DominusEtDeusNatus]

It will shift sooner, but nothing big. Maybe 200rpm sooner on 1-2. 300rpm on 2-3. Your times will still improve.

[hawgs]

so my times should go up .6 from 3.08s? i ran a 15.40 with 3.08s last night it was 15.89-15.99

[DominusEtDeusNatus]

It's more like 4/10s. You ran both times in the same weather? Your 60s should be much better or something else is wrong.

[hawgs]

the runs werent made in the same weather so i am factoring part of that in too, but my 60' last night were terrible 2.3's and i was hooking just fine :(

[DominusEtDeusNatus]

You have some other problems. 2.3s are too slow for hooking 3.42s. Car doesn't shift into 2nd during the first 60 feet so it's not your shift points.

[hawgs]

i was on my 17" WS6 polished wheels... didnt put on my 16s think this is it maybe?

[NBMA4V6]

theres nothin wrong with your car ross.. get the PCM fixed and then go back to the track on the 16's... when i was on 17's the best 60's i could get was 2.2 but i was spinning a bit...

im blaming it on the wheels...

post this in the drag racing section with all the times and we can figure out what wrong..

[bluecmaro96]

your easiest way around the shift points is to buy a pcm from a 3.8 the same year as yours with y87 option

[hawgs]

<blockquote>quote:</font><hr>Originally posted by bluecmaro96:
your easiest way around the shift points is to buy a pcm from a 3.8 the same year as yours with y87 option<hr></blockquote>

tell me how and where...