im not sure if this has been discussed here already but i wasn't really able to find anything recent or helpful. anyways, i started tuning my car again and basically have a pretty good tune right now for CA 91 oct.

3600rpm 11.5AFR (peak boost)
4000rpm 11.3
4500rpm 11.2
5000rpm 11.1
5500-7000rpm 11.1-11.0

timing starts at 2* at peak boost and ends at 13* by 7000rpm.

mods: 05 evo with TBE (hfc), denso 720's, walbro, hks 272 cams (straight), aem cam gears zeroed out, boost set at 21-22psi, bpr7es @ 0.028 gap.

i'll log my car and get no knock, but my EGT's will go above 900C easy, like 920's by the time i hit redline. im not sure if my EGT probe is accurate or not, but it's easily less than a yr old.

should i be concerned with this? i've seen people say that as long as you're not running too rich or lean, and as long as you're not knocking that you should be ok. should i have this mentality?

i don't see anything wrong with the way my car is currently tuned besides the EGT readings, unless someone else has a suggestion as to why i am seeing what i am seeing. i'm running zeitronix to log AFR, boost, and EGT.

 

What if you lean the top end out to 11.5 or even leaner?

This would be good because then we can confirm/bust the whole 'add more fuel to keep temps down' theory...

 

those egts are pretty high. i wouldnt go any leaner for the sake of testing unless you have the means to repair your motor. the same theory can be confirmed/busted by adding some fuel and seeing if the egts go down. if that doesnt work maybe buy a new sensor to see if yours is fouled.

 

Where is the EGT probe located

 

(1st) far left runner, about 3 inches away from the block. im using zeitronix's EGT probe as well.

 

EGTs are meaningless. If you are not knocking, then you are fine. EGTs were used on DSMs as a substitute to logging knock. Knock generates higher EGTs. Now that we can log knock, then there is no need to pay attention to EGTs.

 

hey naji. well, i was just looking at some old logs from when i JUST installed the sensor. i noticed that my EGT's were 50C less than what it shows now. example. @4000 and 5000rpm my EGT's are 750C and 800C, respectively. in my current zeitronix logs my EGT's are 800C and 850C. i guess i won't know for sure unless i buy a new sensor. rofl

im thinking that i am ok though. right? haha

 

EXACTLY!!!

 

You are fine. The EGT is an old DSM practice that should not be used anymore. I bought an EFT gauge and I did not even install once I was informed that it is meaningless. EGT gauges, SAFC tuning and narrowband tuning should be banned from the Evo. Unfortunately, in SoCal they still use them

 

Oops...

He he...

BUT, I don't use mine for tuning, only to tell me that I am about ready to see my motor go ka-blewie!

 

off topic: hey naji, how much boost are you running on 91? u think you can show me ECU controlled boost sometime? hehe

i'm still running my dejon... :-\

 

EGT's will also be high if you don't get a good burn and some raw fuel ends up in the manifold and combusts there instead of the cylinder.

 

I got mine hooked up, but i never look at it. Besides EGT probes are known to take a crap AFIK. Probably more so with time.

 

my egt probe is on the 2nd runner right behind the heat shield. my afr's drop to about 10.9 by redline. doing wot 3rd gear runs (evo 8) my egt's get up to 1660*F or so pretty consistantly by redline. with evoscan I get zero knock. I've tracked the car many times in 100 degree weather like this w/o issue. I'd say you are fine.

I agree egt's arent very meaninful these days when its so easy to monitor for knock.

 

EGT are far from useless. The problem is people dont know how to use and understand whats happening. When you have a good safe tune your egt will be at 825-850.

There could be many things causing this.
1 probe could be failing. doubtful though as usually go way off scale or just die.
2 timing is too retarded. if burn cycle is retarded that means more heat will end up in exhaust manifold.
3 fuel is lean. are you sure your a/f is not going leaner above 7000 in 4/5 gears? injector duty should always be less than 85%. after that injectors are static. you get no additional fuel after 85%. dont be smarter than simple math. if see 85% at any time during tuning it time for more fuel.
4 knock. knock sensors are just microphones. they are far from perfect at detecting all kinds of knock. egts skyrocket when knock is bad. and they go up small amounts for small knock events.
5 preignition. hots spots in the chamber (spark plugs too hot) can cause combustion within the cycle no where near TDC. this causes egt to go up as well. there will be no knock on your knock sensor. simple rule of thumb. one heat range colder for every 100hp.

the first thing I would try is a colder plug. and prep the electrode correctly. file the sharp edges off.