EGT probe in Jake elbow

[UpstateNYoilburner]

So I did a search on this, and holy smokes! I have on '05 3500, NV5600, 4:10 gears. I want to install a basic edge module for towing. Engine will be stock, other than K&N, and straight piped exhaust. Without the wirlwind of pre/post probe arguments, can anyone with experience tell me safe temps to watch. Towing about 16k.

Thanks

Matt

 

[NIsaacs]

All 3 of my rigs are post, I use 1000* as max.

Nick

 

[Wingate]

When pulling hard in high ambient temps at less than 500ft. A. S. L... my POST turbo temps run approx. 950 degrees if Im below 2K RPM and at max boost(34 psi) for over about 10 seconds... . IF I am running above 2K RPM, the exhaust temps drop to about 800 with the same load. . The temps ran approx. 150 degrees higher before the Smarty Jr. when in the same conditions.

 

[cerberusiam]

If you took anything away from the discussions around probe location it should have been there is no one number that is valid. Too many variables will impact what is the max sustained post turbo temp for an individual truck.

You can guess and use the typical 900 degrees max on a stock engine. If you modify the engine, exhaust, air intake in any way then the number is invalid. At one point you may want to limit post turbo temp to 800 degrees, at other times 1200 may be fine. You will not know what number is valid where until you put a probe pre and post turbo then drive it in multiple conditions with multiple loads.

Even though the pre turbo is still a representation, it is still much better and more indicative of actual temps and fluctuations than post turbo. Really, the only question you need to answer is how much of a gamble are you willing to take with the location of the probe.

 

[rbattelle]

In my opinion, it depends on what you're trying to accomplish with the gauge.

Post turbo more accurately indicates the temperature of the turbo, which s useful to prevent hot shutdowns.

Pre turbo can't tell you anything about what the turbo temperature is, but provides an accurate reading of what the engine condition is. Nevertheless, I suggest NIsaac's advice is reasonable if you're looking to estimate the engine condition fro a post-turbo gauge.

On a stock engine, do we really need to be concerned about excessive EGT from the engine? My understanding is that these engines, stock, are rated for max continuous power at 100% throttle, full load, 2800(?) RPM. That assumes, of course, no stuck injectors or other malfunction.

-Ryan

 

[cerberusiam]

He is looking to install an Edge. At that point any and all info about temps and a stock engine are invalid, too much variation in driver and usage to guess at.

Bottom line, EGT probes are installed after the turbo in well know engine configurations and fueling maps. They have been extensively tested and compared to pre-turbo to determine what the optimal max temp is.

The scenario the OP describes is NOT well known and documented with accompanying max temps. Considering the Edge's potential to run hot, its a no brainer where the EGT probe needs to be.

 

[AH64ID]

As it has been pointed out the post turbo is good for turbo temps for shutdown, otherwise it's not really useful in determine what's too hot for the motor. The temp drop across the turbine can be 50° or 400°, depending on load, rpms, etc. This variable is especially true with the very high backpressure created by the HE351.

I would drill/tap it before the turbo and then you know what your looking at.

I don't like the Edge for towing, it runs too hot and it's hard to tell how much timing it has added. I would look into analog gauges and a Smarty Jr.

Also, do NOT run a K&N air filter they are called turbo killer for a reason.

 

[Wingate]

k... i gotta throw this one wrinkle out there... the stock manifold is a split design that has a divider at the turbo flange. If you drill the back side of the divider, then you are only reading an average of cylinder 4,5, and 6. Drill the front, and you get 1,2,and 3... . So pre-turbo only tells half the story. ????

Individual port temps would be the way to go if one is serious about pre-turbo port temps.

As for myself, I spent several years pulling various loads in extreme heat with the stock fueling and a post turbo thermocouple. I added the Jr, and have seen the temps drop across the board...

ANd I completely agree with AH64ID... ... Almost ANYTHING but a K&N...

 

[cerberusiam]

At any point on the manifold your only in 1 to 3 cylinders, but, the readings are closer to true and the reaction is a lot faster. Choosing rear cylinders(3) is recommended because they run the hottest. The danger of 1 injector going bad and not catching it is there unless you have a probe outside each cylinder, no matter where a single probe is located.