Engine/Transmission (1998.5 - 2002) The Ultimate VP44 Q&A Thread

[Mark_Kendrick]

Originally posted by HiPerf360

Mark when did you make 450?

I haven't been on a dyno lately but I was hitting 445-460 using my gtech. I take it to a local scale then find a flat area and do runs going both directions, then throw out the high and low as errors.



I hope to get toa dyno in the next two weeks to see how it does w/the cam and injectors.



... ... ... ... ...



Marco's engine brake was pretty accurate. In our world with our turbos we reach the limit of what our boosted air charge will support.

HiPerf360 has seen enough fuel to reduce power. The optimal for racing is being on the ragged edge of losing power. Then a shot of N2O helps out so you can throw some more in there. For daily driving you don't want any smoke except for when a rice burner 'needs' it







Later,

Mark

 

[MCummings]

Mark Is Gonna like me for this post

Originally posted by Marco

There is no real damage to the engine with smoke( other then soot in the oil). Also a little smoke is inherent with the diesel combustion.

The real damage you do with BIG SMOKE is to the combustion. Inefficient injection, or too much fuel for the air charge in the cylinder, both harm the combustion. What you see then is smoke. In the case most of us are interested in, it harms HP.

Ok, that's cool, I was concerned that way overfueling could 'cause hot spots in the cylinders and pistons that wouldn't show up on a EGT Gauge.

Example: Going down the road at 1200* EGT Pre-Turbo, could there be hot spots that could 'cause Engine Damage even though the overall EGT is "Safe" ?



What I think about this first section is this,,,, Correct me if I'm in Left Field. .

If you have Huge, Shower Head Injectors, but can't get enough air in your truck... That it is a possibility if you stepped down to a smaller injector you could burn more of the fuel, and more HP Could be possible ? Or atleast Efficiancy would come way up ?

From this limit-point on, as we further increase fuel (load) we'll obtain always more smoke.

Marco,, I guess in Italy this is a bad thing? But In reality I haven't Experianced BIG Smoke. Here comes Muncie though.

What happens? The engine isn't capable to burn all the fuel we're injecting. The smoke we see is oxidized but unburned fuel.

Inside the combustion chamber the excess fuel cools the burning flame thus it "absorbs" part of the combustion energy, which we wanted to translate into Hp.



In our imaginary engine test, we've gained 1 hp for every fuel-load increase. From the "inefficient combustion point" on for every fuel increase we'll see 1/3 Hp increase. As we go further with the fuelling we'll see the HP decrease.

I think what Marco is saying is that the motor in his example needs a B-1 turbo with the Big Exhaust Housing.



Excellent post Marco. I see all the stuff you are saying about efficiancy and smoke, etc. This what what your ECM's are all about.

But then to think that a guy like me would buy your High HP Re-ProgRAMmed Smokeless ECM, and then put a heavy fueling box on it. ,



To keep the thread slightly on topic,,



Is it possible to take a VP44 apart,,, and then RE-Assemble it? If so, if you had a few pennies you could have a high quailty machine shop bore out the plunger cylinders, and make bigger plungers.



The Curious,

Merrick Cummings Jr

 

[Marco]

In my previous MSG I've said:"We have reached the limit of the engines efficient combustion".



Sounds pretty much like a point of no return. That's NOT!



I should have said instead: We have reached the limit of the engines efficient combustion, in this configuration.



Anything we can do to raise the combustion efficiency will raise the "smoke point". After all, that's what we're all trying to do, introduce more fuel and more air into the engine...





"Is it possible to take a VP44 apart,,, and then RE-Assemble it? If so, if you had a few pennies you could have a high quailty machine shop bore out the plunger cylinders, and make bigger plungers. "



Yes it is possible to Re-Assemble the VP. I'm working on the plunger thing, but it's very difficult.



I'm leaving for the weekend, see ya on Monday.



Marco

 

[TxDieselKid]

Originally posted by Marco

I should have said instead: We have reached the limit of the engines efficient combustion, in this configuration.



Anything we can do to raise the combustion efficiency will raise the "smoke point". After all, that's what we're all trying to do, introduce more fuel and more air into the engine...



Marco

QUICK, MARK SEND THIS MAN A B-1 TURBO!!!



So marco let me get this right, you are now looking at doing plungers for the VP44? Better do an in-house install only.



Andrew

 

[Paul Somers]

This has been great reading. I love to know how things work. Questions this thread has raised for me ; if the VP-44 is having trouble because of lack of lubricant in diesel fuel now, what is going to happen when the sulphur content is lowered again in a few years? I'm sure that means even less lubricate. Maybe they need to license the Cat/Navistar injectors. No injector pump.

 

[ToolManTimTaylor]

That's why I swear By Howe's.

Lubricity is the #1 Factor here folks.

 

[SmokinJoe]

Everyone vote for the Show/Smoke program!

Originally posted by Marco

Sounds pretty much like a point of no return.

You have convinced me to stay stock till your ECU is ready. I was also thinking of buying the most expensive/smokey injectors. Looks like I should wait on that as well.



I think it bears mentioning that most CTD owners will want a 5th program, the Fogger. This will be a program that as soon as the tps is shows any movement the SMOKE should start.



It would be good for this program to run for a short period of time and then allow us to move to a more normal one. Keep up the hard work.

 

[Marco]

No,No,NO,NO!



Guys you did not get my point!

Please read again what I've said. I'm NOT saying that my ECM is the perfect solution. ( Couldn't do that, cuz the verdict is still out) What I'm saying is, the system-engine must be efficient as a WHOLE.



Example, we all know that hugh injecors alone don't do the trick, you'll need also a bigger turbo...



To expand my thought's further, I think we need better injectors to push the actual HP limit of the 24 V further.



Now, the ECM is surely a part of the system-engine, I can change it's settings to adapt it to new components that might be developed for the 24V. In other words, I can make perform a system-engine more efficiently (with the ECM) than it would with the ECM's stock settings.



Example, from III's injectors up the engine stalls when it's put into D/R (AT). I can cure that. ( Partially)



Another example. With the wildest software we have now, that could be considered the 5/fogger (yes the ECM can produce smoke depends what we want from it) the engine rev's up fast, produces boost fast... with a UNLOADED truck. Use the same file for towing and you'll get SMOKE with poor engine performance.



WHY?



Too much fuel, too soon... Efficiency point... . I have to delay the fuel increase in order to make the turbo spool up, once the turbo spools I can give it more fuel...



Too much fuel harms performance.



I don't want to sell ECM's, not yet. What I wanted to do here is to share some knowledge.



Marco

 

[JR2]

Marco - I see you relocated your IAT, where did you move it to and what benifits did you see?

 

[Diesel Freak]

Marco, one more question.



Since you have had some success reprogramming the ECM, what have you done to "bypass" the inherent limits of the current CAN Bus protocol?

 

[Mark_Kendrick]

Marco,



It looks like a few folks will have to think long and hard on some of the finer points of the discussion.



Be patient folks there's a lot of studying and wrenchturning that goes along with the answers to these question and discussions.



Marco. . the new injectors are only 7 holes but they are HUGE!!! they make DD3s look stock. The truck idles well but smokes like a freight triain. I'm gonna have to put it on the dyno to figue out if any of the less agressive settings of the PE comp would be beneficial.



I intend to use N2O so the excess fuel won't be excess when it counts.



I think maybe that a tweaked ECM will be in my future.



I got the CD on the VP-44, unfortunately I left it at the house. I'll have to get the wife to zip it and FTP it to the web for me.



Thanks for the time and effort Marco. I can't wait to see what happens next.

 

[Marco]

IAT

I've relocated the IAT to the intake horn.

Benefits? Hmmm let's see , less smoke, less smoke @ start with hot engine, a little snappier performance, all in all the MPG has remained the same ( maybe slightly better), most of all no more dirt build up on the sensor.



Marco

 

[Diesel Freak]

Originally posted by Diesel Freak

Marco, one more question.



Since you have had some success reprogramming the ECM, what have you done to "bypass" the inherent limits of the current CAN Bus protocol?

?

 

[Mark_Kendrick]

Re: IAT

Originally posted by Marco

I've relocated the IAT to the intake horn.

Benefits? Hmmm let's see , less smoke, less smoke @ start with hot engine, a little snappier performance, all in all the MPG has remained the same ( maybe slightly better), most of all no more dirt build up on the sensor.



Marco

What size hole and thread count is necessary to mount the IAT sensor? I may consider this.

 

[Diesel Freak]

another question.



what is the PDU address for the VP44?



000, 100, 010, 001..... etc. etc...

 

[Diesel Freak]

is there only 2^12 possible ways for the VP44 to respond?

 

[Rob Thomas]

What size hole and thread count is necessary to mount the IAT sensor? I may consider this

Mark, I did this also, can't remember the size off hand,but I'll bring the tap to Muncie fer ya.



Later, Rob

 

[Marco]

Tap?

I'm sorry, can't remember what size the tap is. Must be an age thing...

Shouldn't be too difficult to find out, just pull the IAT and you'll see.



Marco

 

[Diesel Freak]

I think I will try and answer my own question.



What would you all say if I told you that each PDU on a CAN Bus using J1939 can only have a max command value of 2^11, or 2048 because of the 11 bit identifier. and since there is possibly two PDU's in the VP44 (an assumption on my part) then that number does not double, you would just have values 0-2048 for PDU 1, and 0-2048 for PDU 2.



Marco, how much power can your ECM produce with a truck equiped with DD3's and a stock HX35/14 (yep my ETH came with a 14cm Housing)

 

[Diesel Freak]

it can get even worse

this was sent to me today!



The "command value" must be the portion of the CAN identifier that

J1939

designates as the PDU. That's the only thing that fits the rest of her

question.



As to the maximum value of 4096, well yes, kind of, but not really. It

depends on exactly what level of PGN/PDU you are talking about. The

following is from the J1939/21 standard:



5. 2. 5. 2 Group Extension (GE)

The Group Extension field, in conjunction with the four least

significant

bits of the PDU Format field (note that when the four most significant

bits

of the PDU Format field are set, it indicates that the PS field is a

Group

Extension), provide for 4096 Parameter Groups per data page. These 4096

Parameter Groups are only available using the PDU2 Format. In addition,

240

Parameter Groups are provided in each data page for use only in the

PDU1

Format. In total, 8672 Parameter Groups are available to be defined

using

the two data pages currently available.



The total number of Parameter Groups available can be calculated as

follows

in Equation 1:

(240 + (16 * 256 )) * 2 = 8672 (Eq. 1)

where:

240 = Number of PDU Format field values available per data page (i. e. ,

PDU1

Format, PS Field equals Destination Address)

16 = PDU Format values per Group Extension value (i. e. , PDU2 Format)

256 = Number of possible Group Extension values (i. e. , PDU2 Format)

2 = Number of Data Page states (both PDU Formats)



So you see, there are 4096 type 2 PDUs per data page (of which there

are 2

although only the first one is defined). There are also 240 type 1

PDUs per

data page.



As for absolute min/max values of this identifier, well, 0 is obviously

the

minimum, since this is an unsigned value. The maximum value that can

fit

within 16 bits is 65535, so there is your range (per page).



Unfortunately, that doesn't mean much. First of all, not all PDU

formats

(msb of the PGN) are defined by the standard. This doesn't keep

undefined

PDUs from being used, however. There is provision for proprietary

PGNs.

And not everybody adheres strictly to the standard.



Further, if the PDU format is a type 1 PDU, the lsb of the identifier

is the

destination address and the lsb of the PDU is 0x00. As stated above,

there

are 240 of these per page (0x00yy thru 0xEFyy where yy is a destination

address 0x00 thru 0xFF; the PDU itself is of the forn 0xZZ00, where ZZ

ranges from 0x00 thru 0xEF).



If the PDU is a type 2, then the lsb is really part of the identifier

(the

group extension discussed above). As stated above, there are 4096 of

these

per page (0xF000 thru 0xFFFF).



I'm sure the SAE standards committee cares about this definition. As

someone who uses the J1939 protocol quite heavily, all I care about is

whether the PGN is a type 1 PDU or a type 2 PDU so I know whether to

break

out a destination address or treat the whole 16 bits as a single value.



Hope this helps.