Sorry I just saw the read it again and saw the confidential part.
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| How many injection events? http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=29940 |
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| Author: | nursecosmo [ Thu Feb 28, 2008 12:10 am ] |
| Post subject: | How many injection events? |
I have read from people who should know, that the Bosch common rail system with non piezo injectors has from 2 to 5 injection events per combustion cycle. Where can I find reliable info about this? Is a nox reduction injection used like the 05 Dodge Cummins? If we do indeed have more than 2 events I would like to ask Inmotion about a custom tune eliminating superfluous fueling events. |
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| Author: | gmctd [ Thu Feb 28, 2008 5:07 am ] |
| Post subject: | |
Unfortunately, that is the beauty of CRD pilot injection systems, and why you don't hear the hard rattle like the 12v Cummins and other mechanical and semi-EFI systems - ECM will inject as many bursts as necessary to meet requirements, starting with a lean 'pilot' burst to initiate combustion, several more across the combustion event as required for operator demand\loading, even at the far end of the c.e. to keep max push on the crank arm. Where Cummins is running into problems is with the 'intelligent' catcon - if it is loading up, ECM will inject additional fuel to raise EGT's which unclogs the cat - unfortunately, that hurts fuel economy, as the extra fuel doesn't make extra power, being too late in the c.e. to do anything butcept increase EGT, much like blowing black smoke from running too rich. Prollem with the Inmotion\kermit stuff will be if they cannot break the 545RFE transmission codes - DCJ already is detuning the engine to protect the trans (choked-up muffler, TMR sense, EMCC, F31\37, etc), so unless someone figgers out the magic, any 'custom tune' will also get you custom(er) time in yer fav transmission shop. It's gotsta be the same stuff in the Hemi and other DCJ gasser (patooie!) SBC systems with their own TMR, EMCC, etc, which is Mitsu on Mitsu, so it seems like it should be just a short step to the same end in the CRD Bosch on Mitsu system The Dodge Ram 6.7L on 68RFE is only 6mo old, so there's not much development, as of yet, but that would be the same scenario, with TMR, EMCC, and etc - whoever does that deed will kill three bugs with one fell swoop |
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| Author: | Uffe [ Thu Feb 28, 2008 6:48 am ] |
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If www.vmmotori.it is anything to go by, up to 5 injections happen every cycle... gmtcd you always come across as a funny guy. Funny, yet knowledgeable. Very interesting post. |
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| Author: | crd liberty [ Thu Feb 28, 2008 7:18 am ] |
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Uffe wrote: If www.vmmotori.it is anything to go by, up to 5 injections happen every cycle...
gmtcd you always come across as a funny guy. Funny, yet knowledgeable. Very interesting post. I went to the vm site above and there are some good cutaways of the engine and other parts that some of the members here maybe be interested in. I really like the cutaway of the FCV. Lots of gears there to jam up with slimy oil crud. Steve |
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| Author: | MrMopar64 [ Thu Feb 28, 2008 8:13 am ] |
| Post subject: | |
There are 2-3 injections depending on operating point. You'll only have more than 3 if you have a DPF and are post-injecting to regenerate the filter. |
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| Author: | nursecosmo [ Thu Feb 28, 2008 11:55 am ] |
| Post subject: | |
The 04.5 to 06 cummins trucks don't have a DPF but they do have what everyone refers to as the third injection. The third injection's sole purpose is to lower NOx emissions by binding any free O2 left after the main event, it doesn't recharge the CAT. There are a number of programmers which eliminate that last spurt and increase mileage considerably. Of course I do not want to eliminate the pilot injection but if the VM M fuel mapping is similar to the Cummins map, we may have a superfluous final injection which could be eliminated. MY problem is that I can find no official description of OUR fuel map. I have read gmctd's excellent CP3 writeup at Cumminsfourum many times but can't find specific fuel event descriptions there. My local Cummins guy who also happens to be a Bosch FIE repair instructor doesn't know either. Even if our system does not have that extra after dose, how much would mileage and or power be increased by a mild advance in timing. I would love for the jeep to sound like a real diesel. Thanks for all the great responses so far. |
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| Author: | nursecosmo [ Thu Feb 28, 2008 12:04 pm ] |
| Post subject: | |
Uffe wrote: If www.vmmotori.it is anything to go by, up to 5 injections happen every cycle...
gmtcd you always come across as a funny guy. Funny, yet knowledgeable. Very interesting post. Uffe, you are referring to the RA 428 DOHC with piezoelectric injectors. Our jeeps have the R 428 DOHC which has solenoid driven injectors and can't achieve as fast of a response time. We "might" get 3 injections per cycle but I am still waiting for someone to supply me with the link to an exact description. |
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| Author: | gmctd [ Thu Feb 28, 2008 12:20 pm ] |
| Post subject: | |
If Bosch did it for Cummins, they prolly did it to us, also - I searched the 'net hi and lo at dark and lite, but couldn't find anything on the CP3, just bits here, a piece there - took months to even find a suitable pic - did get some courteous 'invitations' to attend some expensive seminars: "ain't my job, lady - it's my hobby!"- but it's likely that Dodge CRD got close encounters of the third kind for oxides of noxious, and we got 'intelligent' EGR - so, I would guess no binding injection event. |
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| Author: | nursecosmo [ Thu Feb 28, 2008 12:43 pm ] |
| Post subject: | |
gmctd wrote: If Bosch did it for Cummins, they prolly did it to us, also - I searched the 'net hi and lo at dark and lite, but couldn't find anything on the CP3, just bits here, a piece there - took months to even find a suitable pic - did get some courteous 'invitations' to attend some expensive seminars: "ain't my job, lady - it's my hobby!"- but it's likely that Dodge CRD got close encounters of the third kind for oxides of noxious, and we got 'intelligent' EGR - so, I would guess no binding injection event.
That's what I have run into as well, just bits and pieces of info. Just because we have an EGR and the 5.9 Cummins doesn't, Does not really mean any thing in relation to extra fueling. The late model 5.9s use exhaust/intake valve overlap to keep a significant amount of burnt gas in the chamber. The EGR on ours does the same thing just slightly more selectively. Our engine would benefit (benefit only from the EPAs viewpoint) from a late injection the same way that the Cummins does and I can't see the EPA Nazis letting that one pass. If the injections can be reduced by one shot we would potentially achieve an incredible jump in economy. |
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| Author: | gmctd [ Thu Feb 28, 2008 1:12 pm ] |
| Post subject: | |
What does Inmotion say about it? If they're moving code, they must have some idea as to what's happening during the combustion event - the regular 'tune' is 300, custom is 500, so someone must have some deep skinny on the functional routines. |
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| Author: | nursecosmo [ Thu Feb 28, 2008 1:14 pm ] |
| Post subject: | |
I'm just trying to get some info before I call them so that I can know what questions to ask. |
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| Author: | Uffe [ Thu Feb 28, 2008 2:43 pm ] |
| Post subject: | |
nursecosmo wrote: Uffe wrote: If www.vmmotori.it is anything to go by, up to 5 injections happen every cycle... gmtcd you always come across as a funny guy. Funny, yet knowledgeable. Very interesting post. Uffe, you are referring to the RA 428 DOHC with piezoelectric injectors. Our jeeps have the R 428 DOHC which has solenoid driven injectors and can't achieve as fast of a response time. We "might" get 3 injections per cycle but I am still waiting for someone to supply me with the link to an exact description. You are right. Ah sorry, I got confused by it all. The new JK CRD uses the piezo injectors I believe. The engine is very smooth compared to my CRD... |
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| Author: | nursecosmo [ Thu Feb 28, 2008 3:02 pm ] |
| Post subject: | |
gmctd wrote: What does Inmotion say about it? If they're moving code, they must have some idea as to what's happening during the combustion event - the regular 'tune' is 300, custom is 500, so someone must have some deep skinny on the functional routines.
Inmotion's lips are sealed tight about what they do if anything to the fuel mapping code. My theory is that they change the TPS, MAP and engine speed sensor response portion of the code. |
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| Author: | MrMopar64 [ Thu Feb 28, 2008 8:29 pm ] |
| Post subject: | |
The KJ has 1-2 pilot injections and 1 main injection. The pilot injections will drop back to 1 when the second...can't really talk about when/where/why (it's confidential) but it happens. The 04.5-06 Cummins truck are the same setup. 1-2 pilots and then the main = 2-3 injections. These trucks are also solenoid injectors, just a bigger version of what's in the KJ. The pilots' main contribution is NVH, turn it off and it sounds like a 12-valve. There is no post injection on these engines for NOx control, etc - this I do know for a fact. The Cummins engines use only Bosch injection components. They write their own software in-house for their ECUs. On the KJ there is no "superflous" final injection for Nox control, the ISB325/610 engines have no "final" injection for NOx control. If it did, you'd watch your EGTs run 500-650 degC all the time then. For the Cummins most programmers will cut it back to one pilot all the time and advance the timing with a slight increase in rail pressure. That will help both mileage and power noticeably. If you advance the timing you'll see a definite increase in mileage. You want to focus on the light load / low RPMs areas to realize the most benefit. Of course the noise can be horrendous but the mileage increase can be stellar. For the DPF regeneration that gmctd mentioned farther up, these injections are actually torque forming, especially the post injection closest to the main injection. Because these are torque forming injections, the main injection is reduced so that the transition from non-regeneration to regeneration and back is seamless. Also, the Lean NOx trap that is used requires a "rich" phase to purge the accumulated oxides off the catalyst substrate. This rich phase is accomplished by a slight burst of post-injection. Because the EGTs haven't risen yet, the raw hydrocarbon from the burst cleans off the catalyst. For the regeneration, 20 min at 600-650 degC and you're complete. Of course, if you work the truck hard pulling down the road and manage to keep the EGTs above 400-450degC then you're accomplishing passive regeneration which will extend the interval at which the regen due to post-injection is required. Lots more to share later, that's enough to digest for one post i think. |
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| Author: | nursecosmo [ Thu Feb 28, 2008 10:41 pm ] |
| Post subject: | |
MrMopar64 wrote: The KJ has 1-2 pilot injections and 1 main injection. The pilot injections will drop back to 1 when the second...can't really talk about when/where/why (it's confidential) but it happens.
The 04.5-06 Cummins truck are the same setup. 1-2 pilots and then the main = 2-3 injections. These trucks are also solenoid injectors, just a bigger version of what's in the KJ. The pilots' main contribution is NVH, turn it off and it sounds like a 12-valve. There is no post injection on these engines for NOx control, etc - this I do know for a fact. The Cummins engines use only Bosch injection components. They write their own software in-house for their ECUs. On the KJ there is no "superflous" final injection for Nox control, the ISB325/610 engines have no "final" injection for NOx control. If it did, you'd watch your EGTs run 500-650 degC all the time then. For the Cummins most programmers will cut it back to one pilot all the time and advance the timing with a slight increase in rail pressure. That will help both mileage and power noticeably. If you advance the timing you'll see a definite increase in mileage. You want to focus on the light load / low RPMs areas to realize the most benefit. Of course the noise can be horrendous but the mileage increase can be stellar. For the DPF regeneration that gmctd mentioned farther up, these injections are actually torque forming, especially the post injection closest to the main injection. Because these are torque forming injections, the main injection is reduced so that the transition from non-regeneration to regeneration and back is seamless. Also, the Lean NOx trap that is used requires a "rich" phase to purge the accumulated oxides off the catalyst substrate. This rich phase is accomplished by a slight burst of post-injection. Because the EGTs haven't risen yet, the raw hydrocarbon from the burst cleans off the catalyst. For the regeneration, 20 min at 600-650 degC and you're complete. Of course, if you work the truck hard pulling down the road and manage to keep the EGTs above 400-450degC then you're accomplishing passive regeneration which will extend the interval at which the regen due to post-injection is required. Lots more to share later, that's enough to digest for one post i think. Finally! Some meat! But how are you privy to this info? What was the change in programming between the 03-04.5 and 04.5 610 that makes them produce so much soot at the tail pipe drop the MPGs as well as having lower NOx? How can any of this info be used to our advantage in the Jeep? |
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| Author: | nursecosmo [ Thu Feb 28, 2008 10:43 pm ] |
| Post subject: | |
Sorry I just saw the read it again and saw the confidential part.
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| Author: | Uffe [ Fri Feb 29, 2008 3:34 am ] |
| Post subject: | |
MrMopar64 wrote: The KJ has 1-2 pilot injections and 1 main injection. The pilot injections will drop back to 1 when the second...can't really talk about when/where/why (it's confidential) but it happens.
The 04.5-06 Cummins truck are the same setup. 1-2 pilots and then the main = 2-3 injections. These trucks are also solenoid injectors, just a bigger version of what's in the KJ. The pilots' main contribution is NVH, turn it off and it sounds like a 12-valve. There is no post injection on these engines for NOx control, etc - this I do know for a fact. The Cummins engines use only Bosch injection components. They write their own software in-house for their ECUs. On the KJ there is no "superflous" final injection for Nox control, the ISB325/610 engines have no "final" injection for NOx control. If it did, you'd watch your EGTs run 500-650 degC all the time then. For the Cummins most programmers will cut it back to one pilot all the time and advance the timing with a slight increase in rail pressure. That will help both mileage and power noticeably. If you advance the timing you'll see a definite increase in mileage. You want to focus on the light load / low RPMs areas to realize the most benefit. Of course the noise can be horrendous but the mileage increase can be stellar. For the DPF regeneration that gmctd mentioned farther up, these injections are actually torque forming, especially the post injection closest to the main injection. Because these are torque forming injections, the main injection is reduced so that the transition from non-regeneration to regeneration and back is seamless. Also, the Lean NOx trap that is used requires a "rich" phase to purge the accumulated oxides off the catalyst substrate. This rich phase is accomplished by a slight burst of post-injection. Because the EGTs haven't risen yet, the raw hydrocarbon from the burst cleans off the catalyst. For the regeneration, 20 min at 600-650 degC and you're complete. Of course, if you work the truck hard pulling down the road and manage to keep the EGTs above 400-450degC then you're accomplishing passive regeneration which will extend the interval at which the regen due to post-injection is required. Lots more to share later, that's enough to digest for one post i think. I love those technical posts! I crave for more! 
Sometimes I wonder if I should have chosen the mechanical engineering route instead of the electrical one... A little question regarding EGTs. Can you define a few ranges for me, I consider buying an EGT gauge to monitor the EGTs so I'd like some CRD specific knowledge of the EGTs. Range 1: Low temperatures (idle, newly started engine, idle to allow turbo to cool evenly) Range 2: Medium low temps (cruising at 50mph flat country) Range 3: Medium high temps (cruising at 65-75mph various country) Range 4: Towing at speeds over 50mph I'd like this just to give me an idea of where I should expect the temps to be... |
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| Author: | MrMopar64 [ Fri Feb 29, 2008 9:06 am ] |
| Post subject: | |
Yep - I've spent the last 3 years in various forms of involvement with KJ, the new KA/KK/JK/RT platforms with the Panther engine, and then the work here at the university with the 2.5L so you tend to acquire all sorts of knowledge. For the Cummins trucks, a lot of changes were made. The ISB325 engines had a different camshaft with more overlap so that it would trap more combustion gasses in the cylinder and effectively have some EGR. However, the more EGR you run (from any source - camshaft design, EGR valve @ intake, etc.) the more soot you'll make since the combustion chamber is filled with inert products. EGR also makes the combustion process much cooler. This is where the increase in soot comes from as seen at the tailpipe. The mileage drop comes from the pure fact that to make power you have to inject more fuel and then run more boost so it doesn't smoke. The emissions reduction came from the addition of an oxidation catalyst (DOC) in the exhaust pipe. Generally, a C.I. engine is considered a "lean burn" engine because it always operates with excess air. However, if you can run slightly "rich" (i.e. when you make a little soot) then the DOC will oxidize the NOx into N2 and O2. This only happens when it runs rich which isn't fairly too often, so a combination of overlap to have EGR and injection timing are the main factors for NOx reduction on these trucks. The tailpipe emissions levels are so much lower because of the DOC which uses excess O2 to oxidize HC (hydrocarbon) to H2O and CO2, and oxidize the CO into CO2. The big thing for diesels is the regulation of total CO2 output. Some regions regulate this more strictly than others, but in Europe for example, vehicles get taxed/penalized based on how much CO2 (grams/km, etc) it makes based on homologation. |
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| Author: | gmctd [ Fri Feb 29, 2008 11:47 am ] |
| Post subject: | |
Good posts, MrMopar - keep'em coming That emissions timing scenario is why the proliferation of aftermarket "racing" camshafts amongst the Cummins groups - alter the intake\exhaust duration to keep the exhaust valve open as the intake valve begins to open, such that Boost pressure will blow the combustion residuals out of the cylinder, ensuring a fresh cool charge of O2 for the next combustion cycle = more power - plus, helps to control overall engine coolant temps by lowering residual EGT-induced temps in the head and piston crown Result is cooler operating temps under load, with more power and better fuel economy from each injected fuel charge - the first week after purchasing the mechanically-injected 12v CTD 3500 dually in my sig, my first tank of fuel netted 25mpg, because I was driving it like an old man in a big Diesel truck - it dropped from there as I installed the upgrades, not because the 'tune-ups' ate more fuel, but because I began using\craving the increased power - yet, even with all the enhanced perks, I can still achieve that mpg by taping a fresh egg to the exhiliarator pedal. And, no - that's not a mispelling - also, unfortunately, I prefer the egg with bacon, toast, and hot coffee, so you know how that goes, eh..................... Also, Uffe - EGT isn't dependent solely on rpm - loading raises EGT's as the engine makes more BTU as required to move the load and keep it moving - generally: Idle - 275*F (Idle loading increases when transmission is in any gear-range - more aggressive torque convertor (lower stall) = higher loading = necessity of add-on cooling - on the other hand, lower stall reduces operating temps because of lower slippage when not in lockup) 30mph - 350-400*F 50mph - 450-500*F 70mph Cruise - 550-650*F 70mph cruise, 5000lbs trailer with heavy wind resistance - 750-900*F, depending on head-wind and terrain - 1150-1200*F pulling that load up a hill (which is where I back off, btw) Boost pressure is a good indicator of loading, as was the old Economizer vacuum guages for the gassers (patooie!) - low Boost, low EGT's = low loading, good economy - hi Boost, EGT's increasing rapidly = hi loading, economy down the tube (which is why you, as a Diesel owner\driver, need Boost and EGT guages: to keep an eye on the life-pulse of your engine under all conditions - still cain't figger out why oem's didn't use EGT's to monitor\control Boost\fuel rates\Boost) For those spark-infested engines (shudder!), which sometimes have dual exhausts - - hi vacuum = low loading, throttle plate(s) nearly closed, good fuel economy - low vacuum = hi loading = throttle way open, economy down the tube(s) |
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| Author: | warp2diesel [ Fri Feb 29, 2008 2:26 pm ] |
| Post subject: | One of the hop up chips |
Just before I bough my CRD and a little time after I found a hop up chip manufacturer selling on eBay stating that his has up to 7 pulses per cycle and generates more power with out jacking up rail pressure. I figured that since we do not have piezo electric injectors, this would cause premature wear and not be what the advertising claimed. Would Piezo Electric injectors and a flash not yet developed by InMotion give us the performance of the newer version of our 2.8? Any thoughts? Steve |
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