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Discussion Starter #1
Alright so haven't received any response on where to stick a pyrometer if you don't want to delete the EGR and cooler. So I took H&S pyrometer location and adapted it to my stock system. I tapped the EGR intake as close to where it attaches to the manifold as possible. I've attached pics to help. I also spoke with my local dealer service manager regarding if he thought a pyrometer located on the EGR intake was a good idea. He really couldn't think of any reason why not. My only concern was that the exhaust flow might not be sufficient enough when the EGR was closed to provide accurate exhaust temps. He informed me that the EGR is open a majority of the time and I should be getting fairly accurate readings.

So the pyrometer has been in for about a week now. I've got an Edge Insight displaying both readings from the newly installed pyro and from the stock EGT sensors. The new pyro while towing is approximately 400-500 degrees hotter than the stock post-turbo sensors. The highest temps I've seen so far have been going up a pretty steep hill, towing about 7000 lbs, at 55mph. The EGT read at 1325 pre-turbo and about 800ish post-turbo.

I'll keep posting as I use the new sensor more. Has anyone heard what the max pre-turbo EGT should be? I know on the older pstroke max was 1250, hopefully the 6.7 is a little higher.
 

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1325 degrees is too hot for any turbo IMO
 

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Discussion Starter #4
1325 degrees is too hot for any turbo IMO
I thought so too, especially for a bone stock truck, not running any tunes. I sometimes haul up to 18000 lbs with this truck, I haven't yet seen what the EGTs are when I have that much weight behind me. Hopefully they don't get much higher.
 

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I thought so too, especially for a bone stock truck, not running any tunes. I sometimes haul up to 18000 lbs with this truck, I haven't yet seen what the EGTs are when I have that much weight behind me. Hopefully they don't get much higher.
It is probably well above that when it goes into regen for 10 minutes at a time.
 

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It is probably well above that when it goes into regen for 10 minutes at a time.
True. I think the problems with turbo failure start to occur when you have extended periods of high EGTs. I'd imagine that the high EGTs during regen probably decrease fairly rapidly once the regen cycle is complete... assuming that your not pushing the truck real hard.
 

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Has anybody tried towing a heavier load with a stock truck while monitoring the EGTs pre turbo compared to the Post turbo sensors behind the downpipe?
 

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1325 sounds about right for pre turbo, hell some of the dodges get 1600-1700 pre turbo
Sounds like they're all the same. My buddies Duramax sees 1400 all the time pre-turbo. My stock motor with Towing tune sees max 1000F at stock sensor 11 (concluding the pre-turbo temp would be in the 1400-1500 range during these peaks).

There's a lot of talk about high temps and impact on aluminum components, and I'm no turbo expert, but at last check the turbine housing (where these hot exhaust gases traverse) is all cast steel and the turbine wheel, or more importantly the bearing that suspends it, is oil-cooled for this very purpose. The compressor side of the turbo (where all the aluminum exists) isn't even directly exposed to these hot exhaust gas temperatures. So frankly I don't see where all this concern comes from...
 

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I don't fully understand. The OP (from 2011 mind you) states that he tapped the pipe as close to the exhaust manifold as possible, at the intake of the EGR. Now I won't say I'm an expert at this stuff, but doesn't that 1325* exhaust run thru the EGR to get cooled before heading back to the turbo?? Of course the intake to any cooler is gonna be hot, that's the point of the cooler. Maybe I am understanding the flow of the system wrong here...
 

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You are correct that the exhaust temp being taken is the EGR intake which will get cooled, but this is also the exhaust temp that has to go through the turbo then through the downpipe. The purpose of the EGR cooler is to cool the exhaust so it be injected back into the intake system to be used as dead cool air.
 

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You are correct that the exhaust temp being taken is the EGR intake which will get cooled, but this is also the exhaust temp that has to go through the turbo then through the downpipe. The purpose of the EGR cooler is to cool the exhaust so it be injected back into the intake system to be used as dead cool air.
Curious to learn more about the how the EGR functions on the 6.7l, can you or anybody else provide a little more detail? I get Exhaust Gas Recirculation for the purposes of emission control, but am not familiar with the "cooler" aspect of the diesel EGR.
 

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Curious to learn more about the how the EGR functions on the 6.7l, can you or anybody else provide a little more detail? I get Exhaust Gas Recirculation for the purposes of emission control, but am not familiar with the "cooler" aspect of the diesel EGR.

Exhaust gases exit the exhaust ports into the inboard exhaust manifolds. Exhaust gases are directed to the dual inlet
of the turbo via the right and left side up-pipe. The exhaust spins the turbine wheel inside the turbocharger. The turbine
wheel spins the compressor wheel(s) via their common shaft. Some of the exhaust from the passenger side manifold is
directed to the EGR valve through the EGR inlet pipe. When the EGR valve is being operated, exhaust flow goes through
the valve then either through the EGR cooler or bypassing the cooler. This is done by the EGR cooler bypass valve. The
exhaust gas enters the lower intake manifold and combines with the fresh air.



The EGR system allows cooled (inert) exhaust gases to re-enter the combustion chamber, which lowers combustion
temperatures and Oxides of Nitrogen (NOx
) emissions.
EGR system control is based off an air system model to estimate the percentage of exhaust gas in the cylinder. The
PCM looks at engine temperature, intake pressure, exhaust pressure (EP), RPM, and engine load to determine the EGR
flow rate. The ratio of MAP and EP is used by the PCM to estimate a desired EGR valve position. The desired position is
compared to the actual and the duty cycle is adjusted to meet that desired position for the required EGR flow rate. If the
rate is not achieved with EGR valve position, the intake throttle body closes to a desired position, reducing intake manifold
pressure. Reducing the intake manifold pressure increases the pressure ratio allowing more exhaust to fill the intake
manifold at a given EGR valve position. As more exhaust gas is introduced into the intake manifold the amount of air
measured by the Mass Air Flow (MAF) sensor is decreased.
The 6.7L has a hot side EGR valve due to it being before the EGR cooler. Once past the EGR valve, the exhaust gas is
either directed through the EGR cooler or bypasses the EGR cooler. This is done by the PCM controlling the EGR cooler
bypass solenoid which turns vacuum on or off to the actuator on the bypass door. The EGR outlet temperature (EGRT)
sensor measures the temperature of the exhaust gas leaving the system for cooler effectiveness and bypass control.

Also the cooler is split, the "hot" side is connected to the primary cooling system, the "cold" side to the secondary.

The original idea to have the regen exhaust stroke on the left side only was to protect the EGR system from the heat of regen.
 

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Exhaust gases exit the exhaust ports into the inboard exhaust manifolds. Exhaust gases are directed to the dual inlet
of the turbo via the right and left side up-pipe. The exhaust spins the turbine wheel inside the turbocharger. The turbine
wheel spins the compressor wheel(s) via their common shaft. Some of the exhaust from the passenger side manifold is
directed to the EGR valve through the EGR inlet pipe. When the EGR valve is being operated, exhaust flow goes through
the valve then either through the EGR cooler or bypassing the cooler. This is done by the EGR cooler bypass valve. The
exhaust gas enters the lower intake manifold and combines with the fresh air.



The EGR system allows cooled (inert) exhaust gases to re-enter the combustion chamber, which lowers combustion
temperatures and Oxides of Nitrogen (NOx
) emissions.
EGR system control is based off an air system model to estimate the percentage of exhaust gas in the cylinder. The
PCM looks at engine temperature, intake pressure, exhaust pressure (EP), RPM, and engine load to determine the EGR
flow rate. The ratio of MAP and EP is used by the PCM to estimate a desired EGR valve position. The desired position is
compared to the actual and the duty cycle is adjusted to meet that desired position for the required EGR flow rate. If the
rate is not achieved with EGR valve position, the intake throttle body closes to a desired position, reducing intake manifold
pressure. Reducing the intake manifold pressure increases the pressure ratio allowing more exhaust to fill the intake
manifold at a given EGR valve position. As more exhaust gas is introduced into the intake manifold the amount of air
measured by the Mass Air Flow (MAF) sensor is decreased.
The 6.7L has a hot side EGR valve due to it being before the EGR cooler. Once past the EGR valve, the exhaust gas is
either directed through the EGR cooler or bypasses the EGR cooler. This is done by the PCM controlling the EGR cooler
bypass solenoid which turns vacuum on or off to the actuator on the bypass door. The EGR outlet temperature (EGRT)
sensor measures the temperature of the exhaust gas leaving the system for cooler effectiveness and bypass control.

Also the cooler is split, the "hot" side is connected to the primary cooling system, the "cold" side to the secondary.

The original idea to have the regen exhaust stroke on the left side only was to protect the EGR system from the heat of regen.
A lot of awesome info here! Thanks!

Follow up question tho, what makes an EGR so bad for the engine then?? Sounds like it has certain advantages to help it perform more efficiently and cooler so why delete it automatically? I get the dpf and scr system's drawbacks, but don't really see one here..
 

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Is that condensed soot or oil from the CCV? Maybe a little coctail of both?

Exhaust gasses don't burn, they had their chance. They rob available potential power which would reduce fuel consumption, which would reduce primary emissions. If the EGR was a good thing for the motor they would have been on engines before mandated by the EPA. The only upside I see to this design is a coolant warmer, and would aid in engine warmup. Older engines had intake air heaters.

Remember all that black diesel smoke is still getting produced, it's just being masked and "cleaned" by the engine, exhaust, and your wallet. The cooled exhaust gasses still contain soot which when cooled condenses in the intake system further reducing potential for power and efficiency. This starts in the EGR cooler, then the lower intake, turbo, CAC, upper intake, the back of the intake valves, injectors, exhaust valves, and then into the DPF. Also with direct injection there is no fuel washing over the intake valves to help keep them clean. This is referred to as coking. I'm quite sure there is a huge carbon footprint from manufacture, distribution, repair, and disposal of all this "green" stuff.

Let's not forget it takes MORE diesel fuel to reduce emissions, which more fuel takes more fuel to deliver, and more energy to refine, and more oil derics to get more oil, and less service life of the engine. The means don't justify the ends in this case. People just see less end product emissions and are happy.

There was a thread where a member bought a 6.7 in Mexico City there wasn't an EGR, DPF, SCR, or DOC on it, but last I heard it only made 350hp. Not sure if it would have a CCV or not.
 
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