My 04.5 runs a LOT cooler on a big hill at 60 mph in 5th vs 6th. Autos are a bit of a different story but downshifting WILL lower EGT's on a stick by quite a bit. 1500 empty is pretty dang hot. With my BDTD on 2, truck loaded up to about 11k, I wouldn't see more then 1300 over some big hills with cruise on 70 mph, even lower if I went down to 5th. Mind you i'm also 6" lift and 35" tires, they really don't make the truck work much more.

 

Its all in the rpms... at 60 your rpms are still low in 5th, and super low in 6th... Accelerate in 5th thru 2900, the EGT's will climb. Even on a stick, both my dad and i have 6 speeds... get the rpms above 2500 and the EGT's start to climb, especially stock.

If you have 3.73's then your below 1700 at 60 in 6th, so yes EGT's can drop when you shift to 5th and turn 2200 (2200 is the sweet spot on the HPCR)..

 

Anyone who has ran an exhaust drive pressure gauge will tell you that drive pressure radically increases with RPM. On a truck with a pre-programmed 28psi max sustained boost, increased RPM from down shifting will increase drive pressure with zero boost gain. This is why downshifting is hurting you as far as EGT's. If you had a boost fooler or boost fooling programming via smarty, downshifting would result in higher boost and thus cooler EGT's.

An 04.5+ turbo will run considerably cooler EGT's at 35-40 psi boost than it will at 28 psi. Stock fueling has enough drive pressure and heat to make 35psi when pulling a load up a hill so why limit boost and waste the exhaust energy with the wastegate?

 

Makes perfect sense. Thanks for spelling that out for me.

 

I am running a drive pressure gauge.. and the stock turbo will be above 60# DP by about 35psi, especially if towing, based on 33psi boost and 55psi DP when empty (stock fueling). I have seen your reports on the HE351 and what you report doesn't match what I have seen or other reports on the HE351. You're running it on a 2nd gen, don't expect it to be the same as a 3rd gen.

Yes HP is still increased with the HE351 above 35psi, but the DP is thru the roof.

Even with the WG disabled downshifting does not result in lower EGT's.. maybe on your 2nd gen, but not on a 3rd gen. And actually on a stock truck the DP is MUCH lower due to the WG opening, doesn't ever get above 50, and steadies about 38-40.

The best thing on the stock HE351 would be to get the WG to open about 35, better air for cooling and reasonable DP.

 

Maybe it's the design of the 3rd gen manifold that causes the difference in drive pressure. Boost is 40psi range on mine before it hits 60psi drive pressure. Drive pressure is nearly 1:1 at 35 psi if I'm only turning 1900 rpm. If I maintain the same boost but allow truck to hit 2600 RPM, drive pressure and egt's increase. However, the only way I can get same boost at higher drive pressure is to loosen the wastegate or reduce the load and fueling.

 

I think it's the manifold and the cam profile.

At anything above 1500rpms cruising DP is always 2-4 above boost. Pulling hills is generally 22DP 18Boost, so 1.2:1.

Here is a video of stock fueling WG off. This is two 0-60 gauges, I now have a 0-100 for DP as the EB hits 63psi.

DP on right

video

 

The cam profile drives DP at 1:1.2-1.5, go to a better profile and it will drop.

High DP is a function of the in-cylinder EGR and the 3rd event firing. Move these manifolds and turbos to 1st or 2nd gen and 35 is generally 1:1 and DP starts climbing faster than boost from there due to the housing restriction.

DP just doesn't climb as fast without the 3rd event driving it like the 600's. A HX35/12 modified to close to the same exducuer/inducer sizes reacts closely. The HE351's will flow about what an older 12 would but make better use of the exhaust.

 

I agree... except the 3rd event is gone when you get up to operating temp.

 

Nope, its activated when ECU parameters indicate it is needed to meet power or emissions parameters. If you watch your drive pressure gauge you will see a steep spike in the pressure when it activates. On mine that will be 2400 to 2600 rpms depending on throttle application and load.

With a manual you may have a hard time seeing that as you cannot get a smooth curve across the rpm range. Too much rev up and down as you run thru the gears.

 

That what I had thought for a while, mainly from reading on here; however Marco (of Smarty) recently told me that the 3rd injection event is little more than a myth. All of his work in programing the 5.9 has shown him that the only exists at low engine coolant temps to increase the temp in the cat sooner.. Which once he told me made sence as I have always noticed a higher EGT with a cold engine than a warm one.

As for the 2400-2600 I don't see a real big spike in DP there as evidenced by my video posted earlier. Anytime I am WOT the DP increases faster than the boost, and really starts to climb about 30psi boost.. Which makes sense, Holset lists the HE351 as a 3:1 turbo.

 

Ummmm.....hmmmmm......uhhhh.....since I wasn't part to this conversation I cannot comment on what was said, but, there is a very good chance the language barrier created some serious communication issues.

Couple of things don't add up when this is examined critically:

1. Cummins has unequivocally stated there are 3 events

2. The distinct events show on an oscilliscope

3. Marco has stated turning off the 3rd event lost max HP

4. When you move an HE351 to a single injection event engine DP is NOT a huge problem until you start out of its map

5. DP shows a significant jump when something is activated under hard throttle or high load and the jump is not there under other circumstances.


For the RECORD, I am open to new ideas and information but it has to make some kind of SENSE in the observed reality. NOTHING I see in real world experience puts any faith in the statement "the 3rd evet is an urban myth". How can you discard hard facts, validated observations, design specifications, and real experience for a contradictory theory that has more holes than a cheese grater.

I don't know what the Smarty Jr does with its parameters. I don't know why your truck reacts the way it does, but, its way different than the Smarty Sr works on mine.

Higher EGT's on low coolant temps is the ECU compensating with timing and fueling adjustments. Those are known parameters and reactions. I have run too many miles in varying conditions watching gauges not to know there is a fueling enhancement that is activating right where Cummins has stated a 3rd event to be. Since Marco has stated he has not broken the code that does the actual table interpretation in the ECU and all he can do is change parameters in known tables to achieve rersults, I think he misunderstood your question and you misunderstood his answer.


Sorry to be the bearer of bad news, but, that dog won't hunt.

 

i have same symptons/temps. i can see 1500 easily pulling up small hill with edge juice on level 0,1,2. i see 1000F pulling my same 10,000lb camper on straight highway. even with edge unhooked same temps...i have a 2004.5...

I ended up melting #1 piston, putting hole in valve and dropping seat all on #1 cylinder. thats because i went 115 km / hour???

 

I dont think there was a language barrier. Question "Quick question... The 3rd injection event on the 04.5-07 5.9, when does it occur? Always, low rpms, high rpms?"

Answer "A single word answer. Never!
The third injection event is a myth!
Well almost. Only at very cold temps ( engine temps ) they split the main injection event into 2 in order to help the cat warm up."




If its wrong thats fine, but its the only answer i have heard from someone who has looked at the ECM. There is a guy at Cummins who I have been working with for a few weeks who can't find squat about it.

And the low temp profile fits if the Cummins statement was along the lines of "A 3rd injection event to help reduce NOx emissions"... Well if the Cat is the main way they do it the sooner they heat the cat up the sooner it meets emissions.

Retarding the timing wouldn't help heat the engine up sooner, it makes it warm up slower. More of the heat from the combustion is dumped out the exhaust in a retarded situation, hence the higher EGT's. So dodge can't be trying to warm the motor up, makes sence they are warming up the cat.

As far as the Jr vs Sr I am not sure. That video I linked in stock fueling. And with your Sr are you talking about a spike when you start from a stop? I am not sure at what speed the ECM stops derating the engine, but I would assume a spike in DP/Boost at that speed, probably only noticeable in an auto.

 

so thee is no 3rd stage? why o why are all these stock 04.5s so hot without mods?