EGTs, how hot for short runs.

[drees1]

Pre Turbo Temps

Just some 2 cents.



Preturbo, because thats where it is important to measure.



Preturbo is better for performance enthusiest who wants to be closer to the acceptable edge of operation.



Preturbo probe failure will eat the hot side wheel if it fails under any kind of load. You will not see it unless you pull the housing off to inspect.



Cracks are the result of rapid heating and un even temp distribution, and to a degree total temperature.



At about 1,300 deg F, the ductile Ni-resist material of the manifold rapidly vaporizes which thins out the manifold over time. Same with the turbine housing, especially the divider walls between the front and rear 3 where they join. That area has no outside world cooling.



For racing or short term excursions beyond, only experience can predict how high and how long is ok. I guess this might be more like 4 cents!! For what it is worth.



Doug Rees

 

[K_Arts]

Thanks for the answer Chris... my curiosity had the best of me.



Kev

 

[CumminsPower98]

Well I feel a lot better now after reading all the replies. I have had mine up to 1600º a few times very briefly and past 1600º only once. I also always make sure my engine is fully warm before I poor on the juice. I know what sudden temp changes can do and it takes the life out of an engine to run it hard before all the parts are up to temp because of the different expansion rates.

 

[b.j.oneill]

So what is the max you want post 1100? I have noticed my truck gets about that or higher when pulling fairly heavy loads what is the best thing I can do to lower the EGT's go to a smaller plate? That high EGT makes me very nervous I try not to get over 900 post.

 

[Brandon]

1700 pre cuz thats where the guage stops... .....





head looked good after 6months of abuse

 

[P Madrid]

Thanks for the input. I'm going to experiment pre turbo and post at the same time, just for my own info. I figure I can set up a relay to swicht back and forth between the thermocouples. Any one has an extra thermocouple they want to sale for an AutoMeter Ultra-Lites?

 

[CumminsPower98]

P Madrid,

You don't need a relay to switch between thermocouples. I have a duel setup which works great. I just bought a tiny 6 leg two position toggle switch from Radio Shack and mounted it next to the pyro in the pillar. I hooked the gauge wires to the center terminals and then the two thermocouples hook to the terminals on either end. I soldered all the connections to make sure there was no signal loss.

 

[P Madrid]

Once again thank you for a great idea. I guess we sometimes get all wrap around fancy set ups that we forget about the easy approach.

 

[Forrest]

b. j. oneill,



With the HX35-12, 950 post turbo @ 32psi was approx. 1500 pre



I thought I was safe, but noooooooo.

 

[Cummins Corvette]

Originally posted by Strick-9

K_Arts,

My spa gauge doesn't read higher than 1747°.

-Chris

LMAO!!! Is that like saying "I dunno how fast I was going officer. My speedometer only goes up to 120. " when he pulls you over and askes you how fast you were going?

 

[Deezul1]

A Cummins rep said 1250=all day long, 1350= 1minute, above that= 10seconds.



Chris

He would mess his pants if he knew your peak EGTs

 

[drees1]

That verifys how critical the 1300 mark is, and how important preturbo measured would be to run any time at the limit.



Doug Rees