With stock internals:

What is a safe Maximum EGT?
What is a safe WOT Maximum AFR?


Cooling Mods = Pheonalic Spacer, OTTP Stg1 HE, Dual Pass Endplate

 

You have an EGT sensor?

 

NO limit really, just at some point something will go boom.

 

Well once you find out the answer to question one the answer to question 2 is, whatever afr causes you to not have to pull spark but still results in an EGT lower than the max recommended. I havent seen any cobalt specific information but from a couple sources I've seen the 1600*F number coming up from engines with aluminum blocks and heads.

 

I believe you wanna stay under 1640* I'd have to check to be sure

 

Yes,
Aeroforce Analogic gauge with the probe in #4 riser on the header, approx 2" from the head.

 

Cool.

I only know of a couple of people who have ran them on the LSJ. But as mentioned earlier, there has not been a lot of information shared about what the actual values are under different conditions.

Stock GM tunes command and AFR of 10.8 in PE. For my street tunes I use a commanded afr of 11.8. There are some people who say you can lean that out to 12 or even 12.1 but its really not worth it. No one has ever once proved (on this platform) that a leaner AFR will make more HP.

https://www.cobaltss.net/forums/dyno...s-fact-230350/

If you have some time and want to do some good research on this platform, search for all threads started by 100% Meth and read them all.

 

I also have a EGT in my car. Unfortunately pretty untuned and 10AFR. Goes to about 1400 on those pulls have never seen it go over that. Once i get my car retuned i will post some numbers again so be more accurate.

 

a/f should be lower then a 12.7 of wot otherwise you will go boom shot for an 11.0 or an 11.XX to keep it safe and lars i think your right its 1400 normal and 1200 or something like that with meth. quote me if im wrong

 

Whoa, just stop now. 12.7 would be way to lean with the blower. BUT 11.0 is the lowest you should ever go on gas, below that, power produced drops exponentially in every engine. With 10:1 afr like ULWiz says he has such a low wot egt isnt surprising. When making power you typically want to be seeing the highest EGT you consider safe, the higher the egt the faster the gas moves in the pipe and the more scavenging you have with the least back pressure, it also can show efficient combustion when it is not being caused by insufficient spark advance.

 

EGT's cyl #3, 2"s from the head on stock tune, max out at around 1600*, idle around 900*, cruising around 1200*




...with my first tvs setup/tune(running 6* max timing), Vortex(noodle)header, and probe mounted in the dp right behind the flange(so about 17-18" from the head reading from all cylinder) would hit 1800* if i stayed in it, saw it hit 2000* once(never let that happen again) however i believe that some of those high temps i believe were from unburnt fuel from the cylinders igniting in the exhaust causing the high readings(i hope) either way my car has survived so far

 

Holy ****, that high and 14 inches further from the head than it should have been. Damn, though knowing the the noodle header its a good possibility that you could have just chosen a hot spot to mount the sensor.

 

like i said, 6* MAX timing so im pretty sure it was fuel burning in the header itself causing false readings


but yeah noodle + 20psi = fail couldnt get more than 6* in it(on cali **** 91octane) on an 11.6afr

 

On TVS on a 2.7 and E85 with a 11.8 AFR at redline, at the top of 4th starting from 40mph I dont think ive ever seen my EGT's go over 1400*. They seem to be between 1350 and 1400* at WOT, although at higher speeds I typically just take a few quick glances at my gauges. Cruising on the interstate at 80mph is around 1150-1250*

 

11.8 afr or 0.80 lambda? aka 7.78 afr for e85.

 

oops i forgot i was on the addictive stuff :P :cough: :cough: meth

 

.80 Lambda. I always state AFR in a gasoline value to keep it simple lol

 

I wonder how much EGTs change with E85?

 

Thats good question. I was going to test it this past year but I decided not to put the car back on 91....ever

The only cars I know of around here with EGT gauges are on E85 so I personally haven't been able to get any comparisons.

 

stock tune 3.35" m62 91-93octane never go over 1600*

 

 

It should go down, but only after you increase your advance in all cells to compensate for the slower burn speed of e.