Dodge Tuning - Hints and Tips

[Mep_q8]

I've just realized there's a sample 300C file to take a look at. I've been trying to get my head around the basics of Load, Fueling and Spark on the NGC system but it seems like a whole different ball game compared to Ford and GM. If anyones got some pointers or tips, please let us know so once the software FINALLY gets released, so we have some background information.

What I've written is completely my own theory about tuning Dodges and could be completely wrong. Can't get to bed so wanted something to tire me out.

Load:

The load I've seen the NGCs use is Pressure Ratio. From what I understand this would be (Barometric Pressure + Manifold Pressure) / Barometric Pressure = Pressure Ratio.

An example of a good breathing engine at sea level would be:

14.6psi + 98kPa [14.2psi - 14.6psi = -0.4psi] / 14.6psi = 0.973 Pressure Ratio

Please note to get Psi from Map (kPa) is 1 psi = 6.8948 KPa, or use the HPTuners unit conversion tool. Boost PSI is measure anything over Barometric PSI just to clear things up.

I only hope HPTuners will support the Barometric Pressure PID in order for us to tune these PCMs properly and get our calculations spot on. Good thing at my side of the world is we're pretty much at sea level all over the country so Barometric Pressure should be a good 14.2-14.6psi and tuning should be straight forward.

Fueling:

I didn't manage to find a simple OL EQ Ratio/Lambda table for us to command fueling with, so I've created my own theory. (THIS IS COMPLETELY MY OWN THEORY AND IT COULD BE WRONG AS HELL, I'M WRITING TO BE CORRECTED AND LEARN THE NGC OS SYSTEM)


You've got FA Stoich:


The only way I could understand this was to logically try turning the values into something readable like GMs EQ ratio. This is what I came up with:

If I try change FA stoich into an EQ ratio of 1, the formula I did was:

FA Stoich: 14.7 * 0.0694 = 1.02 EQ

EQ Ratio: 14.7/1.02 = 14.41 AFR (Stoich is 14.7 but there could be another adder that sets the FA Stoich to EQ 1 actual that I haven't found yet.)

Now the FA Power Enrich has a table set up with Pressure Ratio vs RPM.


FA Stoich + FA Power Enrich: 14.4 * [0.0694(FA Stoich) + 0.0186(FA Power Enrichment)] = 1.293

EQ Ratio: 14.4/1.293 = 11.14 AFR

By getting those AFR values at the end of the equation, it does seem like the results are believable and this method could work. I guess the only way would be to actually tune the car and change the FA Power Enrich to give me a 12.5 AFR.

To do this I would reverse the equation:

14.4 / 12.5 = 1.152
1.152 / 14.4 = 0.08
= 0.08 - 0.0694(FA Stoich) = 0.0106(FA Power Enrich)

So in my "theory" in order to get a AFR of 12.5, I'd change the FA PE to 0.0106.

Once I get my commanded fueling out of the way, I'd work on the VE tables. They are set up as Load (PR vs RPM). Since I know how to work out what PR the engine at hand will be running at, and getting my commanded PE set, the VE tuning should be as straight forward as tuning a GM vehicle.

Spark:

Once you get your head around learning how to figure out the load of the NGC platform, tuning spark should be straight forward. The WOT spark tables show higher values then the MBT Spark tables, but once we get the software released on HPTuners, a dyno will come in very handy changing out the MBT of the vehicle and help us to dial in WOT Spark.

Please I again need to state, I have never tuned a Dodge vehicle with a custom operating system. I have tuned them using handhelds, and what I wrote above is what I could understand from the tune file itself. If its nonsense go ahead and let me know, I'll be more then glad to change anything written!

[dsmlights]

great info. I hope that Bill will shed light and eventually do a small how to. The Dodge stuff is definitely different from GM

[Chris@HPTuners]

PRatio is MAP/BARO. eg. MAP is 70kpa, Baro is 100kpa, PRatio = 0.7. It works for boosted engines as well. eg. MAP = 130 kPa, Baro = 100 kPa, PRatio = 1.3

Fuel is Fuel-to-Air ratio, ie. the inverse of AFR. eg. Stoich = 0.0694 FAR = 14.4 AFR

Most of the fuelling tables are adders to Stoich. eg. PE table = 0.0177, the final commanded FAR = 0.0694 + 0.0177 = 0.0871 FAR = 11.48 AFR

Saprk is pretty easy, one table for part throttle and another for WOT (PE). The ECT and IAT spark correction is a little funky but not to hard to understand.

The big thing with the torque management is that everything uses torque management, the idle spark being the most annoying. eg. if you simply zero the torque management spark retard table, the idle suffers as the idle over/under speed uses a torque request. Hence, you'll notice all the idle torque tables in there for both throttle and spark. Absolutely necessary for tuning camshafts.

The ETC code on the hemi's is also not very boost friendly as it is modelled on a flow equation that is referenced to barometric pressure and the throttle opening rate increases as the motor goes into boost. There are ways to limit this effect, its not 100% ideal but its driveable. I've done extensive testing using our own test vehicle running up to 8psi boost

Chris...

[witchertorque]

Chris you really are good in what you do nice job, and hp tuners rocks, i am using it hard for fords and found some tricks

[Chris@HPTuners]

BTW, in the scanner so far I have 200+ PIDs defined

MAP, Baro and PRatio are all there

[witchertorque]

do you think its posible to increase the logging speed in fords an a future i know using less parameters increases speed but it would be nice to tune with a faster data logging frame rate

[Overkill]

Holy CRAP dude, I'm looking at a Chrysler file in my HPT Suite. I didn't realize there was a sample file to view either, I've just kept trying my own file with every beta download to see if it works.

Now I'll never get to bed...

I'll watch my Diablo tomorrow as it datalogs; I've seen that FA ratio and couldn't make sense of it but I'd suggest you're bang on with your theory.

[zippy performance]

On any of the boosted one's you do you'll want to turn off the baro updating. That helps with many issue's including etc.

[Chris@HPTuners]

the problem with the ETC code is due to the flow model they use to determine the throttle position. It is not designed for supercharging on the manifold side of the throttle. It needs a second pressure sensor after the throttle blade but before the supercharger to work properly (and the code to use that sensor).

[dsmlights]

Chris thanks for clearing things up. Looks easier than expected.

[duster360]

the problem with the ETC code is due to the flow model they use to determine the throttle position. It is not designed for supercharging on the manifold side of the throttle. It needs a second pressure sensor after the throttle blade but before the supercharger to work properly (and the code to use that sensor).

The Srt-4 PCM does exactly that and actually uses 3 separate pressure readings,

Baro- pre-turbo
TIP- post turbo but pre tb
MAP - post turbo & post tb

Supposedly the differential pressure between TIP and MAP determines tb mass flow at any given time.


It would be interesting to explore the possibility of introducing the SRT-4 tb airflow model to a Hemi PCM with the added input of an additional pressure sensor.

2004 Srt-4 Cal ID: 05029415AH

[hexdummy]

Unfortunately, from what I understand, the calibration tables may be there, but the actual routines are missing in the Hemi calibrations that take advantage of the additional map input. So unless someone can decompile, add in and recompile the code, I think this is likely not to happen.

[Chris@HPTuners]

yes although the calibration values are there, the code required that uses them is missing

the SRT4 doesn't use ETC afaik.

[duster360]

yes although the calibration values are there, the code required that uses them is missing

the SRT4 doesn't use ETC afaik.

well shoot.,,,No the Srt-4 doesn't use ETC,,thank god.


Also,,,I'm trying to get one of our embedded software/EE to send up a resume.

I've been tuning his 05 Hemi and hes a bit of a car nut so I would think he'd be a perfect fit. we only ~3 hours south

[SultanHassanMasTuning]

so does this actually work and we can pull 2006 300c chryslers? edit and flash?

[rdubord]

Not yet......

[Eric@HPTuners]

Soon

[rdubord]

Soon

YES!!

[MeentSS02]

[Mep_q8]

I hope it takes a really long time to come out. I've just invested in the CMR software. I'll kill the developers of HP Tuners if they release it anytime soon!!