EGT temperatures

[horizontalkev]

I know this has been covered many times, but people seem to have different answers and I can't find anything on EGT temperature in different gears. In second gear WOT Im getting 1620F. Is this okay or am I running too hot? I run 11.5 AFRs full boost

 

[Breezio69]

This was taken off of another site.

When do EGTs become "too high"?

This is a highly debated topic and much was written on it by various sources. EGTs are too high when they begin to pose danger to engine and turbo components. Generally, 1600 degrees Fahrenheit (871 degrees Celsius) is considered to be a good number, borderline high EGTs. It is probably safe to briefly run up to 1650F (899C) degrees. Of course you find people running and various tuners recommending to run 1700F (926C), 1800F (982C) and up to 1900F (1037C) degrees.# These temperatures ARE causing damage to turbos and engine components. Here is an#excellent article on EGTs#by Banks Power, and it pertains to both gasoline and diesel engines.

So if you are running 1600F (871C) EGT, then the temperature of exhaust gas entering your turbo is about 1300F (704C) degrees – as you can see this temperature is at the limit of what your turbo can safely take. That's one good reason to keep your EGTs to 1600F (871C). Keeping in mind that key internal engine components on a road engine are not designed to operate at excessive temperatures (above 1600F (871C)),# the failure becomes certain if excessive heat conditions continue for any significant period of time.

Mods can be done that will help safely sustain EGTs above 1600F (871C). Such mods may include superalloy exhaust valves, oil squirters for pistons and ceramic coatings on all engine components subject to high heat, including pistons, and ceramic turbo wheels.

 

[boost97gst]

Interesting read. OP: 11.5:1, pump gas or e85? Those could be good afrs for both. Its kind of in the middle. Pump gas is running on the lean side and your tune is probably very good to do that without too much knock. If its e85 then your deep in the safe zone. 12.5:1 isnt unheard of on a good e85 tune.

Just checked your mods to answer my question. didnt find anything as to what turbo,cams,tuning, etc.

 

[horizontalkev]

So my 1600F is a little high? Especially for 2nd gear. (EGTs usually increase in higher gears)

Im on 91 pump gas.
T28 turbo @ 17PSI.
6 bolt swap
8an main fuel line 6an return, rewired wally 255 and AEM fuel rail. Cams & injector sizes are still a mystery. Will check injectors & Cams soon for exact size/type. Mainly tuning with crappy 1.3 MAFT. I do have ecuflash but my laptop got ran over. Don't ask.

 

[Pipnorcali]

Heres my egt gauge during a run I try to keep it under 875 c. But as u see this run went to 930 or so I added a lil fuel up top
https://www.youtube.com/watch?v=et97nHzUP2g&feature=youtube_gdata_player

 

[horizontalkev]

Wow that's about 1700f.. How many times can you do that before something melts or breaks?

So you run 875c without any problems?

 

[Pipnorcali]

I run it at the track a few times a year ..on the street I dont rev thst high usally...My a/f are a lil rich and my plugs always look good so I go with it.

 

[dharrison]

this is helpfull, i always wondered about this...

 

[Pipnorcali]

I used to top out at 875 but I switched to a fp mani and the probe was put closer to #1 during the video..right now it runs at a max of 875c as I added some fuel.

are u running a wideband? Or just a egt

 

[boost97gst]

If you can switch to e85 at some point i believe you will see lower egt. Plus all the other benefits.
Just curious but i wonder what an egt log of antilag looks like. I bet it makes 1600* look cold!

 

[LandSpeed-DSM]

Anything regularly over 1400*F is high in my opinion, especially for longer pulls. I rarely get above 1200*F upstream, or about 950*F downstream.

 

[horizontalkev]

Just curious but i wonder what an egt log of antilag looks like. I bet it makes 1600* look cold!

I heard at one point that antilag actually cools due to extra fuel. I could be wrong though. The ecu sometimes dumps extra fuel to somewhat cool down motor. Now seeing as how antilag ignite the fuel once in the exhaust it probably would significantly raise the temperature where the sensor is, while at the same time the piston themselves are getting an expensive cooling. Lol

Anything regularly over 1400*F is high in my opinion, especially for longer pulls. I rarely get above 1200*F upstream, or about 950*F downstream.

Where is your sensor located on?

 

[horizontalkev]

I run it at the track a few times a year ..on the street I dont rev thst high usally...My a/f are a lil rich and my plugs always look good so I go with it.

I mean my plugs look pretty good too. Still worries me though :/

Are u running a wideband? Or just a egt

I have a LC1 wideband and an AEM EXT gauge.

 

[LandSpeed-DSM]

I have two, upstream probe (Turbine Inlet Temp "TIT") is in the runner for cylinder #1 about 2-3" from the port.

Downstream probe (Outlet Temp "TOT") is about 2" from the turbine exducer.

Remember, as a general rule lower EGTs indicate greater overall system thermal efficiency. This is why individually or in combination: tuning for higher dynamic CR, spark angles closer to MBT and running as near to stoich as possible will decrease EGTs.

Because more of that energy is being used to turn the crank instead. Similarly, if you have enough data you can get an idea of how much you are wasting. With both TIT and TOT in addition to that you can determine roughly how much energy is being used by the turbine to drive the compressor.

 

[Pipnorcali]

1400 seems low to me but ive been tunning of the wideband as of late , its been running good (same motor since 2001) and just hit a 12.6@111 off the t28....I dont see how I would even get the egts down that low

a ol timer told me to keep it under 875 so thats what I've been doing..

 

[LandSpeed-DSM]

1400 seems low to me but ive been tunning of the wideband as of late , its been running good (same motor since 2001) and just hit a 12.6@111 off the t28....I dont see how I would even get the egts down that low

a ol timer told me to keep it under 875 so thats what I've been doing..

Also consider that my entire hot side, from port to atmosphere, is ceramic coated.

You could be losing >300*F between the engine and turbine wheel. That's before the wheel extracts energy from what remains, cooling it further.

Granted friction will transfer more heat locally at the wheel tips.. with EGTs leaving the port at those temps even with an Inconel wheel and substantial temp drop.. those tips could well be glowing if you could see them.

Because you are pushing that little T28 so hard, the lower bound for how much you could bring the TIT down is still probably greater than what I'm personally comfortable with.

 

[horizontalkev]

Well if 875c is bad, I was on the highway doing 70 and when I went wot in 5th, at around 4500RPMs, I hit 910C and immediately backed off. Its due to my car suddenly leaning out, was seeing my afr jump around from 9-10.5, then suddenly my afr hit 14 and that's when my EGTs skyrocketed. I might have other problems than high EGTs

 

[LandSpeed-DSM]

EGT vs. AFR will peak just on the rich side of stoich. Sloping down (cooler) the farther into rich or lean territory you go.

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EGT vs. Timing usually follows a horizontal "S" shaped curve

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(These graphs are just for example)

I should also point out that I run E85 and with my IATs having stayed within 20*F of ambient lately I'm going to have little issue with keeping EGTs in check. If it does become an issue I have 14GPH of water to throw at the problem.

 

[horizontalkev]

Yeah that's makes sense. Although I did find what my main problem was. I never drive the GSX, and getting it ready to be my new DD. Well had the shop replace my diff and transfer case fluids and I -think- one of the mechanics messed with my maft. Changed ATLEAST my base settings . And I wish I had an injection kit ): did you make your own?