3.6 Pentastar swap PCM options

[Impasta]

Hi all. First post, will be as thorough as possible. First off, I'm not looking for performance tuning support: I will be paying someone to help me with that when the time comes until I feel comfortable enough to do it myself.

Having said that, here is my situation. I have a 78 Fiat destined to receive a 3.6 Pentastar and 8HP transmission. Having not purchases an MPVI yet (and with no buddies to experiment with) I am having a hard time determining what the best route to go is. Here is what I've determined to be possible options:

Dissect entire donor car, experiment until I know what modules I can turn off without the car freaking out
Get start signal replicator installed on factory GPEC/NGC4A PCM, theoretically allowing me to run the engine without all the extra computer stuff I don't need
Pester Chrysler until they load a 3.6 program on a late model Hemi crate engine controller for me (I wish)

I am also aware of the orange Dart and green Valiant running Pentastars. They seem to be a sort of hybrid between dissecting the car and running the SSR, using a lot of stick shift Jeep stuff.

I know about the SoundGerman 8hp controller, I know I'll probably need a SSR, I know an LS is aluminum and cheaper and more powerful but it's off the table (no 4.3s either. 3.6 or bust).

Which route is the most reasonable to take? Or better yet, is there a healthy resource where I can dig into the capabilities of the MPVI as far as bypassing all that icky stuff? I don't mind taking a 300 apart and using all of it's guts, but that's shoving 10 gallons of wiring into a 5 gallon car. Maybe I have all the pieces, I just need to put them together? No idea!

Any information is appreciated. Thanks!

[duster360]

I own the orange 72 Swinger 3.6L.
https://www.forabodiesonly.com/mopar...tar-t5.361683/


Are you calling the TIPM(totally integrated Power Module) an SSR(solid state relay?)?
I mainly used the TIPM for the CAN bus so the rest of the accessories worked, like the ABS module for MPH, Cruise Control, Lights, Wipers, ect.
If i only wanted the engine to run, I'd only need a TPIM, PCM, SKIM(same vin as pcm) and around 10-12 wires.

Shannon's Green Valiant doesnt use a TIPM but is altogether custom. he has uses a little black, box doo-hicky from AJ at HemiTuner to fool the pcm to stay running. Then he had a fully custom chassis harness made to integrate it into the Valliant's wiring

MPVI didn't help all that much with my swap besides maybe the Radiator fan and turning off some codes.

Blake at DIYHemi.com supposedly has swap harness and unlock for a Hemi GPEC PCM. No reason it shouldn't work a 3.6 PCM. But I think that just gets the engine to run. https://www.diyhemi.com/product-page...ckhemi-harness The 8HP still needs to talk to the Engine.

I'm pretty sure the PCS unit that SoundGerman has its own CAN bus, because we're using it on a Trans dyno to talk to shift 8HP TCM.

Also, RPM Extreme is a Jeep swap shop that makes a 3.6 swap harness for older TJ Wranglers with a NAG1 5 speed auto(nag may be an easier swap than the 8hp). The owner is really smart and may offer some options.

http://www.rpmextreme.com/Product/27...e-Harness.aspx

[duster360]

I have a 78 Fiat destined to receive a 3.6 Pentastar and 8HP transmission.....!

Lets see that Fiat?

[harshmeet]

hello boss,
I was wondering if you have done the swap yet or not. I have a 1972 merc benz w109 in which i wanted to do this pentastar 8hp swap to make it a daily. so i was wondering if you have done it and I could fine some potential info to work with. I want a full standalone ecu tune so that I don?t need to attach any wire to the car and all i need is a battery to power, a ground and fuel make it work.
thanks

[Impasta]

Hey guys, long time no post. Life finally gave me the time to work on this. I ended up picking up the following items for $3k out of a 2014 Chrysler 300S RWD with appx. 200k miles.

3.6 Pentastar engine
845RE RWD transmission
Complete wiring harnesses for engine, engine bay, dashboard, chassis, and console, including CAN hubs.
PCM, BCM, RF Hub, key, start button, both fuse boxes.
Complete radio w/ screen, gauge cluster, dynamics sensor,
Both fuel pumps, ABS module w/ pump, shifter assembly
Some other doodads I can't think of right now.

I found a website and reverse-identified 90% of the connector ends (I didn't strip the car) and have most of them plugged in. I'm going to ground every available ground to a steel bar that will be grounded to battery, submerge the fuel pumps, and let her rip. I know if it runs longer than a few seconds, the security system should be happy but will throw a million codes. I will try to remember to share my progress here, and will be starting build threads on other forums (one for Pentastar, one for Fiat) and will try to remember to post relevant updates here.

Link to the Fiat (white 1979 with no drivetrain) https://www.midwest-bayless.com/t-1-...-For-Sale.aspx

[duster360]

Link to the Fiat (white 1979 with no drivetrain) https://www.midwest-bayless.com/t-1-...-For-Sale.aspx

Its going to be a tight squeeze into that Fiat.
The Pentastar is WIDE. Wider, valve cover to valve cover and just as tall as a Mopar 440 Big block. It doesnt look like even the Fiat 4cly has much legroom.

100_5819.jpg

[Impasta]

Some progress was made, but no fire up yet. The key is recognized by the start button, I can hear the throttle body cycle, and the fuel pump primes. The cluster was asking for a brake position sensor, so I hooked one up, but I believe it needs calibrated. When I hold the switch down and hit the start button, everything dies. My grounds are hooked up sketchy, so I'll be redoing all of them correctly (I was on a short time frame that day) and I have a gas pedal coming as well. I need to buy an mpvi3 to check the codes as well so I can see what's up more clearly. Hopefully fire it up soon!

[Impasta]

Forgot to update: A new brake switch, gas pedal, and PROPER wiring setup was all it took. Also, a LOT of wiring. Reference this video:

https://youtu.be/SMlKYJlYsBg?si=MdfMR87ekyzozMnp

This is the engine harness, ECM, trans, body harness, BCM, RF module, cluster, 1 fuel pump, a battery charger (old battery, needed more voltage), shifter, start button, and some other odds and ends. The "chassis" for grounds is a few bent and cleaned metal bars all bolted to each other. As far as the engine thinks, it's just running a 2014 Chrysler 300. The run time shown proves that security is happy and won't automatically shut it down.