There is a post on another board that quotes a Cummins engineer email stating that their recommended location for the pyro probe in a 2005 Dodge CTD is 2 to 6 inches post turbo and to keep max temps under load in the 700-900 deg range.

I am having a Pacbrake installed tomorrow and it has a post turbo port in it that I can use for a pyro probe. I understand and acknowledge the consensus here is that pre-turbo is the "best" location for the sensor.

If I install the pyro in the Pacbrake port and manage temps not to exceed 900 deg with a bone stock truck (aside from the Pacbrake of course), will the engine be safe under those conditions while towing my fifth wheel up grades?

In other words, is it possible for the EGTs to get dangerously high pre-turbo while reporting post turbo temps in the safe range - essentially giving me a false sense of security?

I'd really like to use the provided port but won't if it means risking an engine or turbo meltdown.

FWIW, I am using an Edge Insight CTS2 monitor with the accessory Edge pyro sensor.

 

I think you already understand the issue going post turbo. You will have to look at the gauge and mentally add 350 degrees or more to get an idea what you really are running.

If you can't look at a gauge and trust it, what good is it? JMHO.....

 

If I make 900 my "redline" instead of 1250 or 1300, I shouldn't have to add anything. I don't really care what the absolute temperature is - only if I am approaching or exceeding a safe threshold. The Insight can be programmed to alert me if EGTs exceed 900. I don't have a problem with any of that. I just wondered if it is possible for the post turbo temps to be under 900 while the pistons or turbo are melting down.

 

I would think 900 would be safe. In any event, if everything is stock, you generally have to pull up a long grade floored before temps will creep up close to where I'd be concerned.

 

the in-cylinder egr used on your truck is very confusing as far as egt go's. stock it can get as high as 1600 degrees but the peak temp at 20* after tdc is way lower than a early 04 at 1200 egt, as you bring up efficiency and eliminate the third injection pulse the the egt will drop to 1200 but it increases the peak cylinder temp quiet a bit, it makes it more like a early 04. the smarty jr does this, restores timing, and by eliminating the third pulse it eliminates a large amount of carbon in the oil. all of my big rigs have the probe after the turbo and i see nothing wrong with using the probe in the elbow but stock on a 04.5 it will be 1250* not 900, only after you add the smarty you use the 900* reading

 

Wow. What a great explanation! Thanks, Carl.

 

Why do all the guessing and "calculating" with the EGT probe installed post turbo?

It is so easy to drill the exhaust manifold for an EGT probe.

Just install it in the proper position, pre-turbo, and that's it!

 

there is no guessing or calculating, once you get the truck set up like you want it and see what the temp is then in the future if it starts getting higher than this then start looking for the problem. most older cat equipment has a lift pump gauge, there are no markings on it as far as psi go's, 3/4 of the gauge is painted green and 1/4 painted red, on the pyrometer use a red nail polish to mark the high and forget the reading

 

I bought my Smarty when my truck was still under warranty. I needed a pyrometer but I didn't want to risk trashing the turbo, so I installed it post turbo. I don't tow heavy, so I set my gauge to alarm at 850.

I've never had an issue. I do occasionally see the alarm start flashing when I lug the truck up hills, especially when towing my small dirt bike trailer.

 

First pull with my new Pacbrake and gauges (pyro post turbo in the Pacbrake housing) and new (to me) fifth wheel trailer (gross weight 12K lbs). Pulling a 6* grade (Sherwin Grade on Hwy 395) at over 100* outside temp, I easily hit 1200* EGT with less than full throttle in 3rd gear. I backed off to stay under 1200* (about 50mph). This supports Carl's statement above. Even so, it was stressful to be lingering in the 1200* range. Now I'm wishing I had ordered my truck with 4.10 gears. I thought a stock truck would be safe to run *****-out.

On a positive note, the Pacbrake held my speed nicely on the way down the same grade. In fact, I had to add throttle occasionally to maintain 55mph. Never touched the brake pedal until I got to a red light in Bishop.