I'm interested in the technical details of the vehicles computer system, what sensors it uses, known operational values, whats been tried, what works, what doesn't, etc... If you can answer a question, please do so, and the more valid technical info, the better. Ok Dodge guys, time for 20 questions:

(I'm using the the acronym PCM for powertrain control module, often called the ECM or the computer. Not sure what you DC guys call it.)

What are the current choices for Hemi tuning?
What works and what doesn't?
Is the current PCM for the Hemi the same as it was on models prior to the hemi?
Do the SRT trucks use a similar PCM?
What sensors are monitored by the current dodge PCM? MAF, intake temps, O2s, etc..
What size fuel injectors come on the current trucks?
What alternative computers have been tried and tested as replacement for the current computer?
What options are available for data logging the current PCM?

As I see it, even running something like a FAST system would only be a band-aid fix.

I'm interested in the technical details of the vehicles computer system, what sensors it uses, known operational values, whats been tried, what works, what doesn't, etc... If you can answer a question, please do so, and the more valid technical info, the better. Ok Dodge guys, time for 20 questions:

(I'm using the the acronym PCM for powertrain control module, often called the ECM or the computer. Not sure what you DC guys call it.)

What are the current choices for Hemi tuning?
What works and what doesn't?
Is the current PCM for the Hemi the same as it was on models prior to the hemi?
Do the SRT trucks use a similar PCM?
What sensors are monitored by the current dodge PCM? MAF, intake temps, O2s, etc..
What size fuel injectors come on the current trucks?
What alternative computers have been tried and tested as replacement for the current computer?
What options are available for data logging the current PCM?

As I see it, even running something like a FAST system would only be a band-aid fix.

1. For 2003 Hemi Ram: Jet Module, Hypertech and Superchips. 2004 Hemi Ram: Jet Module, Hypertech. 2005 Hemi Ram: None.

2. NOS, NOS and more NOS. I have six mods, they are on my signature and increased my RWHP from 262 to 292, RWTQ from 278 to 323.

3. 2003 Hemi has a 16 bit PCM. 2004 and 2005 have a 32 bit PCM. Judging by the amount of time that Superchips and other manufactures took to release their products, they are different from older PCMs. The PCM is always learning meaning that if you drive it like you stole it you'll get the power. If you baby it, the dog comes out.

4. Don't know.

5. We have a Speed Density System instead of a MAF, knock sensors, precat and post cat O2 sensors and torque management of hell.

6. Don't know.

7. No one has crack the code completely so I don't think they have a performance PCM. I read of a DTW member that used a TEC3 standalone and got great results with a turbo. He did loose some stock functions.

8. I will reasearch the data logger.

It probably wouldn't be that difficult to run an aftermarket engine system that allows you to adjust fuel and spark to metered air. That just leaves such a hole without the ability to adjust transmission parameters, alter sensor values, modify emissions properties, etc.

Anyone know how different the older Magnum V8 computers / wiring harnesses are compared to the new ones? What are the tuning options for the older models? Anyone swapped to a differnet DC V8 vehicle (like a Jeel GC), another brand PCM or an older model?

It probably wouldn't be that difficult to run an aftermarket engine system that allows you to adjust fuel and spark to metered air. That just leaves such a hole without the ability to adjust transmission parameters, alter sensor values, modify emissions properties, etc.

Anyone know how different the older Magnum V8 computers / wiring harnesses are compared to the new ones? What are the tuning options for the older models? Anyone swapped to a differnet DC V8 vehicle (like a Jeel GC), another brand PCM or an older model?

Will the FAST computer work on the Hemi by chance???

:nutkick: Not yet. Comp cams is working on the FAST as we speak. I don't know why you couldn't just unplug the engine management wires and leave the stock PCM in place to control the rest of the car's functions. :nutkick:

From what I heard with the turbo guy running the stand alone computer, he still has the stock pcm in place to control things like the abs. The electronically controlled tranny would be the tricky one to control I would think.

What about the Big Stuff 3? It might be another option for a standalone. I'll have to ask Kurt @ Wheel to Wheel and see what he thinks. :)

I cant wait for them to come up with somethin like hp tuners for the hemis, I think theyd be smokin but very tempermental

I heard about a stock srt-8 running 12.99!! a damn station wagon

Perfect Power has the SMT6 available for tunning, mostly fuel/timing tunning only. One of my best friends that had some major head porting had to go to this system to correct his A/F conditions. Another guy I kinda know from DTW is using one in conjunction with his turbo, he has got great results from what he says and loves it.

Good thread. I have nothing to add, but I think this is a good thread. I would like to know where you're going with this though. You plannin on tradin in the SS?

Not trading in the SS anytime soon. I have thought about a Hemi Durango for the family car. Just curious more than anything. When the hemi first hit the market, everyone said how strong they would be once the aftermarket items hit the street. Well, its been years now and there really aren't any simple kits for making big power (besides nitrous) for the Hemi. I assume thats due to the lack of tuning ability, so I thought I'd become informed and get a good discussion going.

From what I've gathered lurking other sites, it's just as stated above. The SD tune and lack of availability of a colder plug prohibits heavy nitrous use. The only thing available for the HEMI tuning wise is handhelds and the Jet chips. We all know that the Jet chips aren't all they're cracked up to be and the HPP3 is mediocre when it comes to tuning in the grand scheme.

I really think once the PCM is opened up, it's gonna be some stiff competition on the street and track.

Yeah, the computer front is bleak.
There are two NGK plugs out now, 4306 is a standard length and one colder, while the 4177 is 1/4" shorter and one heat range colder. The NOS guys use the 4306, the F/I folks are using the 4177. The other bad is having two plugs per cylinder, get tiring and expensive!
The CO guy who converted to the stand alone and manual TB with his turbo freed up a ton of power, close to 80 hp/trq over the stock ECU. He did lose cruise control functions tho.
The 5.7L ( some folks are sensitive to the use of the "H" word ) was a big departure from the older 318/360 construction. Electronic throttle control, totally new ECU, and use of a Mercedes transmission are just a few. It can be done, both a stand alone or piggyback, but the cost is super prohibitive. The stand alone conversion is well over $4000 for the parts and labor, and the SMT6 piggyback will probably go close to $1000 when done. Makes HPT and LS1Edit seem cheap by comparison huh?
They also mentioned the processor change from 2003 to 2004 ( 16 bit to 32 bit ). I also hear rumors that even same year ECM's can have up to 8 different programs loaded. The other rumor is how DC coded the algorithms. I can't remember the term but it is similar to an X-Box where the coding is proprietary and not like any other vehicle brand. Makes it very tough to crack and translate. Combine this with DC not coughing up the codes makes life totally miserable from the tuning front.
I hear the stock injector size is 30lb/hr there Richard, with the latest 6.1L having 42lb/hr models. Oh yeah, forgot to mention the 2003 models has lower fuel pressure, 49 vs 58 in the 2004+ models. Go figure....

RIP? What did you do to your engine?

I think the SRT-10 trucks run the Viper PCM, but don't quote me on that. I didn't realize that the baseline no's on the Hemi's were that low. I thought they'd be higher than that. That's a pretty good driveline loss.

I was thinking the same thing about the SRT10, it would make perfect sense.

KTM, that's some good info there. Just look on the bright side though ... there were enough ambitious and knowledgable folks out there to crack the Xbox code and do something with it, so I still say give it time.

FYI, the hemi uses the same transmission as the 4.7L dakotas do, and I'm not sure the setup on the hemi, but on the dakota, the trans is 100% electronically controlled, but NOT via the PCM. There's a small "TCM" (transmission control module) that looks similar to a heatsink, mounted up front. This thing controlls the trans completely, the only outside work is the sensor values it reads to know when to shift. So eliminating the PCM might not create issues with the trans as long as you can still give the TCM it's sensor values to read. I think.

Aye on the 03 rams the tranny controller is seperate from the pcm. This is how the 03 guys can pull the wire to get the firmer shift. I thought on the 04's the units was merged together and thats why you can't pull the wire on the 04+ like you can on the 03's, though I could be wrong on that.

RIP? What did you do to your engine?

Too much boost + too little tuning = blown pistons and rings.
Another 5.7L tidbit, the upper ring land is veeery close to the piston crown ( ie thin ). Some early F/I guys cracked the pistons under high boost and/or if detonation occurs ( my issue ). DC did this for emission reasons but shoulda installed forged pistons. Well, I guess they live fine when N/A but there is no where near the beefiness of the GenIII motors tho.

FYI, the hemi uses the same transmission as the 4.7L dakotas do, and I'm not sure the setup on the hemi, but on the dakota, the trans is 100% electronically controlled, but NOT via the PCM. There's a small "TCM" (transmission control module) that looks similar to a heatsink, mounted up front. This thing controlls the trans completely, the only outside work is the sensor values it reads to know when to shift. So eliminating the PCM might not create issues with the trans as long as you can still give the TCM it's sensor values to read. I think.

Can't verify if this is true or not. The Hemi option includes a 5 speed auto tranny, 5-45RE, where all other Ram engine options used the 4 speed. Again I would have to check, especially on the Dakota.
Yes, the 2003 model have the TCM separate from the ECM and the 2004+ have the TCM integrated into the ECM. The TMR ( torque management removal ) was good for a 0.3 second reduction in 1/4 mile times. It only impacts the 1-2 gear shift but is a telltale sign of how "conservative" the DC computers are. Everything was engineered to last for the 7/70 powertrain warranty and up. The engine dyno and chassis dyno numbers show a 25%+ drivetrain loss. The CO guy who went with the stand alone controller is a good example of the restrictive computer. Now we wait for someone to break it open. Seems to me that with my home computer getting virus attacks and worms every day, could someone pay on of these hackers to break into the DC auto computer?!?

Problem is that most of those a-holes only do destructive sh it, not constructive.

Its a shame that the computer is so oppressive. The Hemi seams like a well engineered motor capable of big power if it was freed from the computer.

One would think the DC made the computer so non-user friendly so that Mopar can come out with its own chips that would work better then anything else on the market. They will have corned the market on aftermarket. So it begs the question why hasnt Mopar came out with any performance parts yet... . .

No doubt GV! There has been talk of a performance computer from DC but nothing has materialized. Latest info says no performance stuff. They are even doing away with the 7/70 powertrain warranty and going to a 36/36 like most others.
Most rumors say certain engine and tranny parts cannot hold up long term to higher HP abuse. Who knows, they are secretive about everything...

Its all about money. The more performance parts available, the more it will cost them in warranty work. I can guarantee you that our GM trucks wouldn't have near as many options if the vette and fbody cars weren't the same engine and computer system. Thats been a huge help.

Maybe with the new Charger and other V8 DC cars, the aftermarket will start putting more effort into cracking the current DC computer system.

Yep, I totally agree Richard. GM did the smart thing by pre-engineering the GenIII casting for more flexibility. Means there is less R&D required and more sales potential for the aftermarket companies.
There are definitely more 5.7L motors running around now with the 300C, Magnum, and now Charger. Bummer is the mulitple different computers, speed density programming, and self-learning or self-cancelling coding. Makes modding a pain. Superchips and Hypertech are making progress slowly but surely.

Do both the spark plugs on the current 5.7 fire at the same time?

What other semi-current V8 OBD2 compliant DC vehicles have full aftermarket tuning support? Not just handheld programmers, but complete custom tuning at speed shops?

Do both the spark plugs on the current 5.7 fire at the same time?

What other semi-current V8 OBD2 compliant DC vehicles have full aftermarket tuning support? Not just handheld programmers, but complete custom tuning at speed shops?

Actually the DC 5.7L motors are OBDIII now. Another hardship for scanning engine management parameters. We had STFT and LTFT issues with our turbo kits since we use an extra injector to modulate A/F, which caused low speed and part throttle "bucking" and code setting.
The spark plugs do not fire at the same time. Each coil fires the primary plug and a secondary plug at the same time tho. The secondary firing occurs on an opposite bank cylinder on or near the exhaust stroke. Helps with emissions, a problem area on the early engine development. Some folks are modding the wires so it fires both plugs at the same time ( just re-route the secondary wire to the same cylinder ). Dyno has not shown any power improvement, but it seems to help throttle response.

Actually the DC 5.7L motors are OBDIII now. Another hardship for scanning engine management parameters. We had STFT and LTFT issues with our turbo kits since we use an extra injector to modulate A/F, which caused low speed and part throttle "bucking" and code setting.
The spark plugs do not fire at the same time. Each coil fires the primary plug and a secondary plug at the same time tho. The secondary firing occurs on an opposite bank cylinder on or near the exhaust stroke. Helps with emissions, a problem area on the early engine development. Some folks are modding the wires so it fires both plugs at the same time ( just re-route the secondary wire to the same cylinder ). Dyno has not shown any power improvement, but it seems to help throttle response.

Wow. So a big part of the problem is that the computer is actually ahead of its time. OBD3 isnt mandatory until the 2008 model year. Since none of the other manufacturers are OBD3 compliant yet there is some logic in DC holding its hand close to the chest. If DC has had OBD3 on the market for a few years now in really world testing they do have an intellectual property to protect. Having an open code would leave them wide open to industrial espionage

chryler computers are difficult to work with try to get an aftermarket scan tool that will do have as much on a chrysler product as it does on a newer model gm. GM has the tech 2 chrylers scan tool doesn't compare to the info that the tech 2 provides to tech working on the car.

Wow. So a big part of the problem is that the computer is actually ahead of its time. OBD3 isnt mandatory until the 2008 model year. Since none of the other manufacturers are OBD3 compliant yet there is some logic in DC holding its hand close to the chest. If DC has had OBD3 on the market for a few years now in really world testing they do have an intellectual property to protect. Having an open code would leave them wide open to industrial espionage

Interesting, I did not know the OBD3 info. My lesson learned for the day.
Makes much more sense why DC is so reluctant to share the computer coding...

The 545RFE is not a Mercedes tranny BTW. It was built and created by Dodge and only used in ChryCo. vehicles.

Do both the spark plugs on the current 5.7 fire at the same time?

What other semi-current V8 OBD2 compliant DC vehicles have full aftermarket tuning support? Not just handheld programmers, but complete custom tuning at speed shops?

No, the companion cylinder fires the other plug 360* out from power stroke.