Engine/Transmission (1998.5 - 2002) Lets make a custom ECM

[Diesel Freak]

I got to thinking again today about a custom ECM program that is good from idle (800 rpm) to 3950 rpm, 0 to 45 psi of boost, and 0 to 100% throttle position. Throttle position would be an independent variable, with rpm being dependent variable. Boost pressure up to 45psi would be the limiting factor as to how much fuel would be injected on the power stroke. Timing would be a function of rpm only. This means we could take the IAS completely out of the loop, and just use the crank position sensor, MAP sensor and the TPS.



This could either work with a custom pump (VR6) or as a piggy back ECM to use on the stock VP-44 and directly act on both solenoids, eliminating the factory ECM signal, and the “mythical VP-44 pump limit. ”



So, we have 3150 rpm and timing values, 200 throttle position values (0-100% in . 5% increments) and 90 possible fuel volume/boost values (0-45psi on . 5 psi increments)



Peak torque would be at 1800 RPM (700 Ft*lbf) and peak horsepower would be at 3500 RPM (466HP) with 275’s. We would then defuel to a max of 3950 rpm. I however am not completely sure if this is physically possible with the available fuel volume of the VP44.



Here is the neat part about my idea. Max torque is only limited by boost (up to 700 Ft*lbf)…. if you want more power, just tweak your wastgate. After that you would have to really watch your pyro once you started pushing the turbo out of its pressure map. There is also the possibility of some really bad hunting if the turbo went into compressor surge. Hmmm an HX40V would be perfect for this application

EGT could be also limited to 1300 (with stock or 275 injectors) The program would overfuel just enough to promote quick turbo spool up



Now having said this is there anyone who wants to help develop the possible (although all of them may not be used) 56 million possible data points for the custom fuel map?



No wonder the MAD ECM is taking so long.



Come on guys we can do this!





Any suggestions?

 

[klenger]

Wouldn't the valves go through the pistons at 3950 RPM?

 

[Diesel Freak]

get bigger valve springs

 

[TxDieselKid]

better yet...

How about just throwing a Marine head on top of it.



Diesel Freak,

You know that I am with you on this ECM thing, it's just

a)$$$

b)lack of experiance

c)$$$

I want to play with the ECM as bad as anybody. I am convinced that the ESDN software would allow what you want to be done. It's just getting our hands on that, and the inline 2 adapter.



Please somebody get me this stuff, and get DF some a VR6 and we will shut up!!!



AJB

 

[Diesel Freak]

Marine head? there is no such thing... . all ISB's have the same head

 

[TxDieselKid]

who's been telling me lies...?

Theres no marine head? I know the pistons are different, and cam is different but the head I think is different on a marine 12v then a Dodge 12v arn't they? It might just be the spring... . or a screw lose in my head.



AJB

 

[Diesel Freak]

Why in Gods name do you want a 12 valve head?

 

[Diesel Freak]

well, I was hoping for a little more input than this... . so here is some more info. The CAN protocol J1939 that is used between the ECM and VP-44 is 29 bit... . but only 8 of those bits are used to actually tell the VP-44 what to do. There are essentially two pages of information available in the VP-44 microcontroller PCA that are usefull..... therefore the total number of possible settings (fuel volume and timing) for the VP-44 in a stock ISB would be 512. If I am wrong, would someopne PLEASE correct me. If we were to bypass the PCA with our own ECM signal from a 16 bit system that directly operated the two solenoids we could do this.



I am about as computer illiterate as they come, and I have dug up this much..... we could build the ECM with existing hardware for about less than $500 (processor, board, memory, signal amp, 16 BIT DA convertor).

 

[Scooby]

You need to get in touch with Marco. He's been working on this for well over a year. I understood he had some prototypes at one point. I think he was working with HVAC if I'm not mistaken.



Good luck!

 

[MCummings]

Quick,, Go run out of the United States.



From what I understand somebody tried this awhile back, and got there hands slapped by Dodge and Cummins. I think that modifyieng ECM's in the U. S. is a No-No.



That's why Marco is able to do it, unregulated in Italy, BUT, That is also why he is running into problems with the different types of fuel, and also why it is taking ALOT longer than even HE expected. The fuel in Italy apperantly is very different than the fuel here. Even though Marco's trucks runs wonderfull over there, the Exact same ECM on the same type of truck doesn't run as well with the US Fuel.





WHOOPS, Don't want to stuff words into Marco's MAD ECM operation, but I do remember reading this on a thread here @ TDR about the situation of different fuels.



MerrickNJr

 

[ftb87]

Talk to Marco, I though he had a ecm he was developing?





Frank

 

[Diesel Freak]

I am aware of Marco and his MAD ECM. Modifying an ecm is not illegal... as long as you do not use any PROPRIETARY software to make money from it. It is done all the time with imports. I am looking to take the ECM idea a step further and replace the factory ECM with a different unit that does not use J1939. The factory ECM will still be used to operate the Gauges and for the chrysler tech to look at.

 

[Diesel Freak]

so, here is the deal. Three inputs, one digital (rpm) and two analog (throttle position and boost pressure) all three combine to form a 3D map, each point on this map coresponds to specific data in the EEPROM Memory... . the processor reads the incoming data from the sensors, matches it to the data on the EEPROM and sends a coresponding signal to either an amplifier or a set of SCR's to directly uperate the VP-44 solenoids.



It is that easy!

 

[Diesel Freak]

TTT

 

[TxDieselKid]

come and listen to my story about a man named Dave...

Originally posted by Diesel Freak

Why in Gods name do you want a 12 valve head?

2 Words... Dave Mitchell



I don't really want a 12v put they do make power a lot easyer then playing with the computer program. Don't get me wrong, I love my 24v with a COMP but if I were going to do a project truck, 12v baby.



I think you and I are the only ones who want to play with the ECM insted of just slapping Marco's ECM on. Seems like we are the ones who end up shouting to the masses but never get a responce unless from each other.

 

[Gizmo 007]

Yea, here's a response. I'm willing to help out. The mapping is liable to get a little tricky but can be done (Marco did it, I may not).



See what you fellas can dig up on the stock ECM or get hold of Marco. I'm attending college and a job, but still have a little slack time. I'll play with the idea a little, see what I can come up with.



Keep me posted.



BTW: Is the ECM CAN-BUS?

 

[Diesel Freak]

Originally posted by Gizmo 007

BTW: Is the ECM CAN-BUS?

yes and no. .



externally it is CAN (J1939)



internally I am not quite sure, but I bet it is 16 or 32 bit... then it gets converted to J1939 to talk to all other devices external to the ECM



It uses an Intel A28f400FBR flash chip

 

[Todd T]

you guys are nuts

but go for it!!

 

[Mr. Brewski]

There are a ton of single board computers controllers out there that are not that expwnsive and could easily do the trick. The problem with all this talk is getting the programming done and done right (Bug Free). There aint no "Ctrl-Alt-Delete" buttons on an ECM and not to many "Windows XP" upgrades for these Cummins...

 

[Vaughn MacKenzie]

Cliff, I know it would be a challenge enough to produce an ECM using only 3 variables/inputs (Crank position/RPM, boost and throttle position. But I think actual engine temp and intake air temp might prove to have more of an effect than you might think on performance and driveability. ie, the amount of fuel that works great and doesn't produce smoke at 40F will make it a smokebomb at 110F with the A/C running. Or starting up a hot engine in the summer vs in the mountains in the winter. I know adding 2 more parameters would increase the amount of mapping tremendously, but it might be the difference between this being workable or not. Just a thought, if you do end up coming to that bridge