Lets talk acceptable EGTs

[emperorjordan]

So this is my first "fast" truck with a pyro, I have driven big trucks with pyros that I pay attention to while pulling a grade loaded for example, but never on a truck that I would do 1/4 mile runs in.

I recently installed my pyro in the driver side manifold in the end of it like suggested by the pix on Diesel Manor. Initially I wanted to install it in the down pipe right past the turbo like most big trucks I have seen have them, but the general consensus on here is to install in the manifold so I did.

My question is what is acceptable to see?

I have seen it rise to 1300-1400 when doing a 0-100mph run on flat land and the moment I let off it drops to 700 then 500-600 a few seconds later and continues to cool as I coast. What got me worried, last nite I was driving up a grade on a two lane highway going 65 or so pulling 850 degrees or so. I came up behind a loaded semi and stabbed it to pass him. The truck did so cleanly with ease but when I glanced at the EGT as I was getting back into my lane I saw mid 1600 degrees and let off the gas, and it promptly dropped down to 800 and then kept dropping as I coasted for a bit, then got back on it to keep my speed up and it stayed at 800 as it was before.

Are temps that high acceptable or should I not be stabbed passing up a grade, maybe stay part throttle?

I am running Erics Extreme Street and Race tunes, generally EGTs behave the same for both of those.

[colo_dually]

Those numbers sound right for what folks experiance out of Erics tunes. The threashold for me is 1200* if sustained for more than a few seconds. For acceleration, and quartermile runs, momentary spikes upto 1600* are ok. Not the best, but I haven't found much on drag trucks having failures caused simply by high EGT's during drag runs.

[emperorjordan]

Define "momentary" though. If I run 0-100 after a second it is at 1300-1400 and stays there for the 13-15 seconds of the run. Is that momentary?

[Jesse S]

I would consider that momentary. Alot of guys will be pretty conservative when talking egt's. I don't even look at my egt gauge when I race, pull, dyno etc. IMO spikes of 1600* while running the quarter, pulling a sled or messing around on the street are not going to kill your engine. I would not make it habit, but I wouldn't get too worried about it if it happens every once in awhile. You run into trouble when you hold high egt's for long periods of time such as pulling a long grade with a load behind you.

[worldwide73]

Think about saturation. How long does it take metal to get to 1600 degree or 1400 degree and start melting? A few seconds, no, but how long? I set my alarm at 1350, and usually when it starts going off I'm usually going way over the speed limit anyway!