EGT Temp?
BOMBARDIER
Joined: Mar 2007
Posts: 23,293
Likes: 1,322
From: North of You
If its not preturbo you are pretty much guessing what the actual exhaust temperature is. I have seen that it can be 100-400 degrees difference. Which is a HUGE difference.
What size is the probe?
It shouldnt be too hard to locate a fitting for preturbo.
What size is the probe?
It shouldnt be too hard to locate a fitting for preturbo.
Diesel Bomber
Joined: Jan 2008
Posts: 4,525
Likes: 103
From: Havre mt
Its not to hard to believe actually. Its pretty much simple math if you think about. In the space it has to go before hitting the probe, the exhaust has been intrain with air and can cool down quite rapidly.
Say you pour a cup of coffee at 200 degrees, but the time you actually pour the cup, put the pot back, and take a drink, the coffee has already cooled down 30-40 degrees. But the longer it sits it starts to cool down more slowly. So basically, at first the temperature drops rapidly but as it sits it goes down more slowly. Its pretty much all based around the algebraic concept of half life, if that makes any sense...
Say you pour a cup of coffee at 200 degrees, but the time you actually pour the cup, put the pot back, and take a drink, the coffee has already cooled down 30-40 degrees. But the longer it sits it starts to cool down more slowly. So basically, at first the temperature drops rapidly but as it sits it goes down more slowly. Its pretty much all based around the algebraic concept of half life, if that makes any sense...
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i know i can get him one at napa here i cracked mine during the rebuild and got another, just waiting on the tap i sent him in the mail
Last edited by 94cummins12v; Jul 16, 2009 at 01:03 AM. Reason: Automerged Doublepost
N.M. Bombers Director
Joined: Sep 2008
Posts: 797
Likes: 40
From: Corrales New Mexico
Yah I figured that really didn't make too much sense. I can do math but can't explain it. But with heat and other things, it initially has a rapid decrease rate then after a certain amount of time the rate of decrease begins to slow to the point where you don't see any change, which would explain why a pyrometer could be off 100-400 degrees off if its post turbo.
Diesel Enthusiast
Joined: Jul 2008
Posts: 177
Likes: 2
From: Southern Indiana
The temperature drop is more closely related to the work output from the turbine than it is to the heat transfer to the outside air that occurs in that small space. I say that since the basic principle is the same for all turbines, the greater the temp differential, the more work you get out.
In the end you need to get the probe pre-turbo since the temp difference post-turbo is going to vary somewhat accordingly with how much boost is made, so it really is a guessing game.
In the end you need to get the probe pre-turbo since the temp difference post-turbo is going to vary somewhat accordingly with how much boost is made, so it really is a guessing game.
Thread Starter
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Diesel Bomber
Joined: Mar 2009
Posts: 1,007
Likes: 11
From: Arizona
wat you mean get what i paid for? bc it got put post turbo and welded in?
but he said he didnt put it in the manifold bc it would crack. why would it crack if you drill it clean and every thing good? idk but i know im guessing on the temp thats why im goin to move it. nothin in the mail yet brandon maybe the post man needed to put a pyro in his truck. 
but he said he didnt put it in the manifold bc it would crack. why would it crack if you drill it clean and every thing good? idk but i know im guessing on the temp thats why im goin to move it. nothin in the mail yet brandon maybe the post man needed to put a pyro in his truck.
Diesel Enthusiast
Joined: Jul 2009
Posts: 217
Likes: 5
From: natchez, ms
i beleive hes talkin about the cheap glow shifts...some people have good luck with them some dont, seems like about 1 out of every 3rd guage is off on the reading. I know first hand, i tesed mine up against an auto meter and an isspro egt, the autometer and isspro were the same reading the glow sift was about 150 to 200 low, all off the same thermocouple spot.
BOMBARDIER
Joined: Mar 2007
Posts: 23,293
Likes: 1,322
From: North of You
I wouldnt put it in those words but yes, thats what I was meaning. Quality and accuracy count, and most bargain guages arent up to the task.
Diesel Enthusiast
Joined: Jul 2009
Posts: 217
Likes: 5
From: natchez, ms
yeah you would think they work fine unless you actually put different gauges in the same spot. and drove under the same conditions. I thought my truck was running 450 degrees at 70 mph till my buddy told me no way and we swaped in his autometer and it read 650* then i was like ok what if your guage is off so we stuck in an isspro in it read 650* as well in my case the glow shift guage was off. Also the boost guage i had wouldnt read anything under 10psi for some reason. I do like the way they look and would run them but i would check them to make sure they are correct before trusting the readings.
