Competition pre or post egt probe

[twotoe]

my box has arrived i installed every thing but the egt probe. i am hearing two ways to install pre and post. im told some people have had the probe melt off pre turbo and hurt the turbo? what is the best way to get good safe readings ?

2004. 5 ram 2500 4x4 auto 600 tst power box

 

[Cummins4Life]

Put it in the manifold. Drill and tap and set the probe so that the tip is in the middle of the exhaust stream and feel safe in the fact that you're getting accurate readings.



I cant say I've ever read a post in which someone melted a tip off and huffed a turbo, but I have read a few in which people have melted the #6 piston even with the pyro in the manifold. You want to gauge the gasses coming out of the head.

 

[JGheen]

I don't know who told you that if you put the probe pre-turbo that it will melt away, but IMO, I would never speak to them again. There is no way that a thermocouple will melt away from the exhaust of a diesel engine. Just put the probe in pre-turbo and don't go over 1300-1400 for longer than 10-15 seconds or your pistons will be what melts down, not the probe. If you put the probe post-turbo be prepared to do a lot of math when the temps get high as there is at least a 300*F temp drop after the turbo.

 

[snowracer69]

If I can't, and the big sled-pulling guys can't, melt a pyro's thermocouple at 1800*F for 15 seconds at a time, then you being stock are never even going to have to think about it.



Extensive testing by many respected people on here has led to the discovery that the given 300*F difference from pre to post turbo readings isn't the norm. Sure, under a no-load, cruising situation it may be, but put a trailer behind your pickup and go pull a hill and it won't be the case.



Oh, and why in the world would you want to know what is going on behind the important part? Who really cares what temperature the muffler is seeing, it's that turbine wheel that costs the big $$$. Ya, ya, ya... shutdown temps... blah, blah, blah. Let it cool down to 350*F pre-turbo every time and you won't have any problems with coking (sp?) oil on your bearings.

 

[y-knot]

I guess I'm just one of those guy's that care what is happening before and after twister. I would mount the probe pre turbo if you have to choose between the two. If you get it hot enough to melt off, don't worry about the tip there will be plenty of other part that fail as well. For the most part there is about a 100-150 degree differance between pre and post temps. At idle and while hard on it, the temps can get pretty close to the same, but just normal cruising down the road they stay about that apart. Take your time and use some grease on the drill bit and the tap, it will catch most fillings. Then take one of those extendable wands with a magnet on the end and reach down in the hole, and get what metal shavings are left, not a big deal. Good luck

 

[BRayls]

I don't know who told you that if you put the probe pre-turbo that it will melt away, but IMO, I would never speak to them again. There is no way that a thermocouple will melt away from the exhaust of a diesel engine. Just put the probe in pre-turbo and don't go over 1300-1400 for longer than 10-15 seconds or your pistons will be what melts down, not the probe. If you put the probe post-turbo be prepared to do a lot of math when the temps get high as there is at least a 300*F temp drop after the turbo.

van haisley told me that,not really the melt part. but he said to mount it post,so if there was a problem ,I would not be buying a turbo. but what does he know.

 

[JGheen]

van haisley told me that,not really the melt part. but he said to mount it post,so if there was a problem ,I would not be buying a turbo. but what does he know.

Yeah, but what are the chances of the probe breaking and going through the turbo?? The melting part was what got a laugh out of me. I would just rather be safe than sorry on EGTs and not have to do the math everytime I get on it.

 

[Pinion Twister]

Thought i was safe being post turbo, but after switching to pre boy was i wrong.

Seeing almost 600 deg. difference. Same gage and no changes in engine.

If planning on bombing better go pre.

 

[Deezul1]

aircraft use pre turbo so I guess we are ok to do it too

 

[snowracer69]

aircraft also call it "TIT" or "Turbo inlet temp". Oh, and in the two turbo-normalized airplanes that I fly, we run both at 1550*F TIT for as long as we are on the throttles. At 1500*F and below we get severe carbon buildup on the turbine wheel... . so why can't I run 1400*F in my Cummins all day long? Oh, that's right, the pistons aren't the same material, nor are they the same design.



BTW, the planes are a Cessna 206T and a Piper Turbo Seminole.

 

[RCone]

I don't know how it is on a 04 but on a 03, you had better be more carefull with regard to drilling. The process of greasing the bit and using a magnet works fine on the 2gens, but on the 3rd gens the turbo hangs straight down from the manifold. You would need to remove the turbo bolts and drop the turbo down just a tad (that's all it will go) and put a piece of cardboard between the flanges.

 

[Old Man]

Pyro depth

I "think" I read in the past to set the depth of the pyro is to bottom it out in the exhaust manifold then withdraw it 1/2 in. and then tighten (secure) the pyro. How are you guys doing it. TIA.

 

[JGheen]

I "think" I read in the past to set the depth of the pyro is to bottom it out in the exhaust manifold then withdraw it 1/2 in. and then tighten (secure) the pyro. How are you guys doing it. TIA.

My Banks pyro that came with the kit was already pre-set. It didn't have a ferrule on it, but the pyro itself has some kind of ferrule "style" hump on it that would seat against the boss fitting when tightened down. My depth was set by how deep I screwed in the 1/4" NPT boss fitting. I would have to say my probe has about at least 1" to 1. 5" of it in the exhaust stream.