Running into a bit of a wall here and trying to find a good way out.. My friends, i need some help!
I bought a wrecked 2011 impala with a 3500... didn't place that it was the more complex VVT version. That version never came with a manual transmission, so the ECU can't be programmed without the automatic. I was told to grab an 06 G6 ECU as it has the potential to be programmed, but wouldn't be as simple as just taking out the auto transmission from the PCM and may require additional custom tuning... This yes, was my fault as i didn't do the research on all of this before hand... but now i'm trying to find a way forward.
As much money as i've dumped into this already, instead of enduring more headaches and even more cash, i may be looking at going the more simple route and dumping this engine and going to the more tried and true swap.
I'd be looking at picking up a late 90's early 00's car with a running 3400... questions on all of this stuff below!
3500 question... 1) Has anyone here swapped an LZE with a manual transmission? (or any VVT 3500 variant)
3400 questions - i can't seem to find some answers to the questions on the threads i've seen. For this swap, i know i would need an ECU tuned to take out the misc crap... as i'm unfamiliar with this, i have some specific questions. 1) as the VSS i believe is a different set on the 3400 vs the fiero... anyone that tunes it with HPTuners can swap the VSS reading to match what the fiero is putting out, right? 2) is there someone here or someone here that knows someone that can do a basic (non performance) tune, basically to make it just run? 3) is there any other got'chas for the others who have done this swap previously?
The 3500 and 3400 are amazing engines in my opinion. There's a lot of talk about that motor on the V6/60 forums. I ran across this thread and happened to have the tab already opened... maybe it will help: https://www.60degreev6.com/...-lze-engine-vvt-lock
The 3.9 VVT LZ9 engine was available in the G6, with a manual trans, starting in ~2006(?). You might be able to run that PCM - or tune - with a few minor variations, to accommodate the .4 liter difference. I was looking at doing that swap, but decided to go in a different direction. Still may, in the future. I used to have a G6 with the LZE (automatic). I always thought that the LZE or LZ9 would make a Fiero "walk and talk".
For programming options, contact gmtuners.com He goes by "Sinister Performance" or (on this forum - although he's seldom here) Darth Fiero.
[This message has been edited by Raydar (edited 09-08-2025).]
I was told to grab an 06 G6 ECU as it has the potential to be programmed, but wouldn't be as simple as just taking out the auto transmission from the PCM and may require additional custom tuning...
The person who suggested teh G6 ECU to you did it for exactly this reason:
quote
Originally posted by Raydar:
The 3.9 VVT LZ9 engine was available in the G6, with a manual trans, starting in ~2006(?). You might be able to run that PCM - or tune - with a few minor variations, to accommodate the .4 liter difference. I was looking at doing that swap, but decided to go in a different direction. Still may, in the future.
For programming options, contact gmtuners.com He goes by "Sinister Performance" or (on this forum - although he's seldom here) Darth Fiero.
The Pontiac G6 was available with LZ9 3900 and F40 six speed manual transmission in 2006 and 2007.
quote
Originally posted by Kameirocco: That version never came with a manual transmission, so the ECU can't be programmed without the automatic.
Mis-spoke there- i should have said not as simple - in speaking with Sinister, the earlier 3x00 swaps are known and easy to program. But this would take a good bit of work to get going with this specific swap.
quote
Originally posted by Raydar:
The 3.9 VVT LZ9 engine was available in the G6, with a manual trans, starting in ~2006(?). You might be able to run that PCM - or tune - with a few minor variations, to accommodate the .4 liter difference. I was looking at doing that swap, but decided to go in a different direction. Still may, in the future. I used to have a G6 with the LZE (automatic). I always thought that the LZE or LZ9 would make a Fiero "walk and talk".
For programming options, contact gmtuners.com He goes by "Sinister Performance" or (on this forum - although he's seldom here) Darth Fiero.
Yep, that's who i've been speaking to - we had some plans, but was going to get way too expensive way too quick unfortunately - really really nice guy and really knowledge, but since this is an unknown, he said we could get it running, but may require additional tunes, which would require me getting an hptuners box and payign for each tune, which i'd be more than happy with, but i'm on a much lighter budget than that would allow.
We have the complete HP Tuning Suite here and and it allows you to include or exclude many different items on the engine that interface with the PCM. . There is probably good info on getting the VVT feature to work with a manual on the HP Tuners Forum but the easier way would be to just swap the entire powertrain in.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
There's also the option of using a standalone ECU like an MS3. page 90 of the MS3 pro ultimate manual describes how to setup for a GEN IV V8, and the VVT 3500/3900 use the same trigger arrangement.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
Originally posted by Kameirocco: 3400 questions - i can't seem to find some answers to the questions on the threads i've seen. For this swap, i know i would need an ECU tuned to take out the misc crap... as i'm unfamiliar with this, i have some specific questions. 1) as the VSS i believe is a different set on the 3400 vs the fiero... anyone that tunes it with HPTuners can swap the VSS reading to match what the fiero is putting out, right? 2) is there someone here or someone here that knows someone that can do a basic (non performance) tune, basically to make it just run? 3) is there any other got'chas for the others who have done this swap previously?
1. a 3400 PCM will look for the VSS to be directly input to the PCM, the PCM then outputs a 4000 PPM signal that can be converted to run the speedometer. I'm not sure the stock fiero VSS outputs a signal that's compatible with the 3400 PCM.
2. for a stock engine, the bulk of what will need to be done is disabling VATS, setting the trans type to manual (yes there is a flag for it in the PCM) and adjusting the throttle follower settings to prevent the car from stalling when coming to a stop, it should be fairly straightforward.
3a.the alternator will hit the decklid with a stock accessory drive, there are a few ways of low mounting the alternator, some guys mount it where the AC compressor goes, I made my own mount and tensioner arrangement to low mount it.
My alternator bracket
here's a LZx low mount alternator
3b. you're going to need a neutral balance flywheel, from a 88+ 60V6 application. Fidanza makes (made?) a billet aluminum flywheel that works as well.
3c. if you're running the stock PCM, you can't swap timing covers because you will need the 24x sensor thats goes behind the 3400 balancer.
3d. if you low mount the alternator and relocate the coil pack, you can install a front valve cover on the back, which makes oil changes way easier/cleaner.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
FWIW, some people have been deleting VVT, using cam spacers (since the VVT cam has larger journals), and swapping in an LX9 (or that generation) performance cam. WOT-tech has the spacers and the cams (made by Comp, although they may be an exclusive to WOT, since they are not listed on Comp's site.) An alternative is to use an LNJ 3400 cam. The LNJ was specific to the '08 Equinox (and its clones, I would suppose). It has the same larger journals as the VVT cam. It's not a performance grind, however. Since it's not on a single billet, I'm not sure if it can be reground. I would guess no. But it's only a guess. There is also supposedly a Melling timing set available for that engine/cam.
[This message has been edited by Raydar (edited 09-15-2025).]
