So whats the story with the 40 mph lag on the stock pcm? 03 and down im assuming.

Does this mean it takes a little longer to get pickup? Or does it mean that there is simply a loss of power due to the stock pcm telling the car to only push 75%?

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How To: E-Brake Pwn
2001 GTP. D/S Rotors * Custom Intake * DHP PCM *

idk. 4th gear kicks in at about 40 if your cruising. when you punch it, it has to go threw a few gears to get to the optimal gear. so maybe that is the lag???? on the aftermarked pcm's they have a 4 to 2 down shift instead of having to go 4 to 3 to 2. but idk

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white 04 comg G gtp. wizair and pacesetters
personal best 14.6 91mph 2.1 60"
track day in a few weeks

i read somewhere that stock PCM's were one of the most restrictive things dealing with your tranny you could have.

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'06 GP GT S/C...20" chrome Alloy wheels, Kicker L7 Subs, 4-piece grille, white underbody lights, dvd/nav. , tint, custom chrome, custom FWI, 104 plugs... more coming...

Rumor used to be that a reprogrammed PCM allowed "skipping shifts" between 3-1, or 4-1. I think the reprogrammed PCM just reduces the shift response time and raises the shift point in a way to allow the tranny to drop to 1st fast enough to keep the car from not finding it's way there.

I got taken by a Contour SVT one time because I wasn't watching my speedo. My car never went lower than 2nd gear @ 35MPH and I heard him shift 3 times as he went by me.

Skip shifts aren't a rumor. They work.

In stock form, when the car wants to skip shift it will take too long. Say you punch it while in 3rd. It will downshift to second, pause shortly (to allow the tranny's internals to catch up), then proceed to 1st. This is why the stock skip shifts feel slow and jumbled.

PCM programming helps it accomplish the task faster, but it is a bit more harsh. I wouldn't go doing it all the time. The adjustments also allow you to skip shift at higher speeds. At some speeds, it would only shift down to 2nd (or 3rd if you were in 4th). The reprogramming allows it to come into 1st right towards the top of the power band so you get a nice hard surge before it goes back to 2nd. Not all that great for it, but if you're not doing it all the time no worry.

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2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

I guess what I would define skipping a shift is different than the real thing.

Either way, I think we can agree that the reprogrammed PCM responds quicker allowing the car to find 1st gear @ 40MPH.

My 04 does it between 40 and 45. all I do is double pump the throttle quick and it kicks it out of 4th gear and when you get on the gas it goes to right gear. at least thats how mine is. Thats my quick fix until I can get some more mods and a new pcm. idk, it might work for yours.

i agree morris

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99 DARK BRONZEMIST METALLIC GTP SUPERCHARGED SEDAN. --MODS-- FWI, 104 plugs MSD coils and wires, 180 t-stat, dual thrush exhaust, Kenwood complete system 10' Sub ported, raised spoiler, red calis, D/S Baer rotors, Hawk Pads.

thats how i make people feel even worse when i beat em'. "u got a jump on me, and i still beat u!"

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