isx 870
05-26-2020, (Subject: isx 870 ) 
Post: #10
RE: isx 870
Its a slow file pull using 'c a l t e r m' on a cm870. It will take upwards of 45min. So don't get alarmed if it feels like it's taking to long. Basically if you don't get any aborted or stop messages then its still doing its thing
05-26-2020, (Subject: isx 870 ) 
Post: #11
RE: isx 870
(05-26-2020 )Ga boy Wrote:  Can anyone tell me what to look for with bad tune having trouble getting help, i have insite and 'c a l t e r m'. Thanks in advance.

He sent me the file from his truck. Here is what has been seen at a glance. It is not good ...

* Injection timing is so ridiculously advanced that it is not even slightly funny. On the CM870, start of injection timing of more than about +6 degrees at high fuelling rates is starting to push things. It should be more like +5 or less for the 500-550 power range at high output.. and about 4 or so for 600+ hp,.. and for the 665 it is actually trying to make against the ecm's will, it should be in the +4 to 3 range at 1400 - 1500 + rpm's . Here is what some complete idiot did to his main highway mode injection timing map ...


The map is also all over the place. NO smooth negative transition from left to right that would follow the engine curve. No proper positive transition from top to bottom to correctly compensate for rpm increase that follows the engine curve either.

What it looks like on a 3d graph ( WTF MAN??? ) ...
--- Maybe they copied the map out of some ancient 3d shoot-em-up video game? Kinda looks like one of those dungeon maps in World of warcraft or something, -- Who knows! but then agan,.,. looking at it harder,. makes sense now... maybe that huge dip in the high rpm of the map is supposed to represent the the area where all the oil and coolant and engine guts can drain out when she blows her top? (blame it on the

It is simply beyond wacky,.. it is not consistent at all, looks like a kindergartner who was number happy made this.. holy cow batman,... this thing it is a wonder it has not beat a bearing out of it yet!. It is so far advanced that it is not even likely to be able to make proper torque any more without tripping over itself.

What it should have been similar to, using the same graphing chart plot ...
FYI: (idle region in back left corner set for fuel savings @ idle. Then transitions upward to compensate for rpm change farthest away to closest, and rolling off downward from left to right several degrees as torque increases ).

(moving onward)...

* Some dirt-turd jacked the engine brake turbo setting to a full 100% across all tables. - this thing is destined to drop a valve under high load and high rpm with engine brake on high going down a mountain somewhere. -- I have actually never seen one set this high, like some 5 year old must have done this!.. This is the worst one i have seen yet!.

* The program does not match the engine. Not even the wedge offset in the program is correct. Someone are-hoele jumped CPL numbers on this thing. The engine is supposed to have a CPL-8520 program in it made for 6/6 injector and valve cam build profile,.. but the wrong program that is in it is a CPL-8518, made for cam profile 4/6 wedge offsets. These are NOT compatible with each other at all. - ref:

* Some a-hole added a bunch of time to how long the fuelling and timing actuators open for. This throws off ALL OF THE TORQUE AND HORSEPOWER AND TIMING for the engine and screws up all the fuelling solenoid on-times and injection timing solenoid on-times too. It also makes the mpg in the dash of the truck lie like hell and read much higher than the actual fuel mileage. The HP is about 80 or so higher than the ecm thinks it is. Problem is the screwed up injection timing and other garbage, it would smoke like hell under a hard pull and fall on itself to try to make any kind of half decent power... this thing is horrible. - Again,.. some a-hole kindergarten programming if i have even seen it. Again, I have not seen a tune this bad for a few years. I hope like hell no one actually gave the idiot money who did this terrible butcher-work. - Maybe they wanted it to run like one of those redneck pick-up truck sh$it tunes?. What a mess!

* it is missing all re-mapping of engine mode control logic for use without EGR gas. It is missing most of what needs to happen for a proper de-mandate. Here is what was supposed to happen...


its bad ... its real bad... I am not making any sort of exaggeration here. - It looks like one of those old Puke deletes or Diesels$it or Piss-power, maybe junkball,.. big name deletes from back in the day that used to tear the guts out of an enigne.. only thing they did not do is toun the power maps waaay up like the big name idiots do, maps srill have the 585hp setting,.. but with the added 80~ ish hp added to the actuator time logic against the ecm's will, it normally would be as high as is 665HP~ish if it were not for the horrible injection timing, wrong program for wrong cam profiles, wrong injector size programming, way too far advanced timing, and all the other terrible agonizing issues.

-- that is what i see at a glance. Personally, you should not even be running this engine with that program. If I were you, I would take that ecm off the side of that engine and take it to the nearest stealers$it and have it flashed with the correct factory program and unplug the EGR temp sensor, let is have the CEL light on, who cares, but at least it will half-way run right in its factory built in non-egr mode until you can get someone to re-program it properly. At least that way it will not be trying to eat its own guts out all the time.

I see lots of bad programming, but this one is by far one of the worst ones I have seen for a long while. It is reminiscent of those early tunes I seen people do back when the CM870 was popular and new to the market. Back when no one or their cousin knew a damn thing about programming one properly. - There is ZERO excuse for this kind of crap these days,.. ZERO!....

I added it to the wall of shame:

- Whoever made this program should not even be allowed near a lawn-mower, nonetheless a $36,000 commercial engine.


User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
 Thanks given by: 2dlb , HotRod
05-28-2020, (Subject: isx 870 ) 
Post: #12
RE: isx 870
From rawze's run down of the tune. It sounds like who ever turned it was trying to tune the 870 to be a 570, that SOI map looks a lot like a 570 ish map.

The other thing that leads me to believe he was coping from a 570 is the changing of the timing an fueling metering tables. Depending on the cpl in a 570 those tables can be vastly different, even for the same 4/6 cam wedging, it's strange but like Cummins couldn't nail down what was needed an trying different thing to see how it turned out out long term for the motors. The 870/871 on the other hand use the same fueling/timing metering tables across all cpl's an hp ranges.
05-28-2020, (Subject: isx 870 ) 
Post: #13
RE: isx 870
(05-28-2020 )ynot Wrote:  ...
It sounds like who ever turned it was trying to tune the 870 to be a 570, that SOI map looks a lot like a 570 ish map.

They were not even close. Here is the pre-2000 CM570 Sig.-600 (API/APX) finalized start of injection timing map for all 4 (denoted as "4D") engine modes...


The older engines used ATDC offsets and the newer engines use BTDC offsets. So to get a proper visual representation, I had to flip the 3d chart below ( used "zero-{mapped values}" ) to correct for ATDC vs the newer BTDC so that it can be compared visually.

Granted, it is not as smooth as newer maps, but nowhere is there +12 degrees offsets at high fuelling output or crazy and whacky jumps like seen above.

the trouble is that too many idiots will copy paste parameter tables form one engine to another with no reference or clue of its use, or even what compensations may be done to it before it is applied. - I see it all the time, and it is downright shameful how little most of those people who dig around inside other people's ecms really know.

User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
 Thanks given by: HotRod

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