If changing displacement in CMR...

[CoolVanilla]

The issue: when changing displacement in the CMR software, you'll end up with an ESP/BAS light permanently on. Also, your ESP disable button (squiggly lines) will not work. Traction control seems to be somewhat disabled, but you don't have control over how much, or when.

Diablo's default answer has been to not change displacement in the tune, since (1) adjusting for the proper displacement doesn't fix anything in the tune and (2) leaving the displacement as stock will avoid the ESP/BAS light and traction control issues. I believe most tuners are not messing with displacement as per Diablo's recommendation.

However and contrary to Diablo's statements, my testing showed that the car is just a different animal when properly adjusted for its actual displacement. Traction/light issues aside, it just *feels* different. No, I don't have any hard evidence of this and yes SOTP dynos suck... but I'd swear adjusting for the proper displacement woke her up even more than she already was. Perhaps one day I'll get some dyno/track time and we'll see...

Something we can confirm though is that your VE tables all the sudden start to make sense when the displacement is properly adjusted. No longer do you have to scale your values off into outer space. This will make your tuner's day.

Our very own Lafrad, buried in another thread, shared a gem of a fix that he discovered after a weekend of effort. I tried his fix last night and can confirm the issues are gone; the ESP/BAS light is now off and I have my ESP (squiggly line) button working again. Traction control now is in full effect when I want it, and I can turn it off (via the button and GSM mod) when I dont.

Here it is:

Hey guys.
Here is the fix.

There are 2 displacement figures.
One is the "real" displacement. used in fuel calculations, cruise mode, airflow mods, etc.
The other is what the PCM reports to the rest of car.

I have not found this out via "intimate knowledge of the inner workings", I have found this out by trial and error on my car.

How to properly use them?
Set the "Real" displacement to the REAL displacement of the engine. figured out using the real measurements (yours isn't 6.4000000L, so don't set it to that).
The other one can ONLY be set to a number that the rest of the computers in the car will understand. AFAIK, NO 2005 car will run a 6.4L engine... cuz none of them have any idea what it is. I bet 6.1 doesn't even work reliably.
On my early build '05, I can set 5.7 and 6.1 in that "reported" displacement box. Neither has affect on the TCM or anything else... so I'm still trying to figure out why its there. When i set it to something OTHER THAN 5.7 or 6.1 exactly, I get the lights on dash and no proper ESP/problems, etc.

Long story short: Set the "real displacement" to get good behavior of the fueling/spark/airflow/throttle.
don't change the "5.7" or "6.1" displacement unless you want to start trial-and-erroring what computers/components can handle the 6.1 stuff.

PS: THis will also bring your VE's back into the realm of "Real", and your adaptives won't be fighting the tune any longer.

Mike, can you go give a little more detail on what your fix does or does not do to ESP? In other words, will the ESP (squiggly line) button start working again? (How about the GSM mod, if you have it/know?) And presumably will then the Mopar TCM be the ticket to completely avoid limp mode and yet still disable ESP as much as realistically possible?

The value that started out as "5.6xxx" is the one you change to the EXACT displacement of your engine, in Liters. Thats the one that is used for all the fuel/airflow/etc calculations.

The value that started out as "5.7" is the one you leave ALONE, if you wish for the rest of the car to still behave like it did from the factory. That way the button, ESP kill, etc etc etc all work like they did before any Displacement adjustments occured.

Thank you Mike!!

[Mike@Diablosport]

Interesting. Keep digging guys.....good stuff.

[Cam]

Yup, that Mike is.............






Now Mike (diablo). How about coming through with those air flow tables he has discussed with you guys..........







Please!!!!!

[CoolVanilla]

Now Mike (diablo). How about coming through with those air flow tables he has discussed with you guys..........

Please!!!!!

x10!

[USCG Charger]

man this post is way over my head...

[MadCharger]

Great stuff Mike and CV! I agree 100% with you CV. Bob@SVS gave me a tune with the displacement correctly changed to 6.1 to match my new engine, and that tune felt SO much better on both street and strip.

And right in the middle of typing this, Bob emailed me to fix it - gotta love that kind of service!!

[lafrad]

I can be even nicer here:

The same cam has a *VERY* similar shaped VE table in a stroker vs a non-stroker.
5.7 vs 6.1 vs 6.4 vs 7.0

its startling how the tables are almost plug and play from one to the other.

[lafrad]

About the airflow tables... its jsut for the '05's.

I only have... oh... wait... there's a few of them ;-)

I *DID* find the '04 SRT4 injector scale from mopar tho, so yer off the hook on that one :-)