whos REALLY running < 1450F at high power?

[acannell]

90 daytona ES 2.5 turbo
lots of mods, dynoed at 230whp and 280wtq @ 14 psi

just installed exposed tip EGT probe on runner #4, about 1.5" away from head

EGT's peak at 1690F at WOT...

wideband O2 says AFR is 11.5 at that moment

soo.....is this too hot? is this normal?

who is REALLY running 1450F or less EGT's at these power levels, WITHOUT methanol or water injection?

i have a HUGE front mount intercooler (equivalent to 3 stock cores)

[xtrempickup]

ive never seen over 1300 on my egts running 23lbs of boost on a T3/T4 54 trim stage 2 turbo on a TIII motor. i run alki and pump gas. my car runs consistently cool on the egts

[jim34]

My car runs 1450 at 18 psi, at 26 psi she goes just a hair over 1500. Running cast pistons and 11.2-11.4 afr, 12 degrees timing 89 roller cam strait up and my probe placement is the same as yours.
I also have a very nice intercooler but my piston rings are a lil loose

[acannell]

now THAT is weird...i have a swirl port head..what head do you have? why would my EGT's be so much higher? are you sure your EGT probe and gauge respond fast enough for you to see the peak temperature? what kind of probe do you have?

[janus]

imho 1650°F is really a LOT. what pistons are you running??
i got this from another thread about EGTs (the high egt @cruisin thread)

Quote:

Originally Posted by speeduphoria you also get high EGT's from rich A/F, so you would need to know what side of stoich you are on before making adjustments. High EGT's during cruise wont kill your motor, you prob need more timing in cruise because some of the gas is burning late into the exhaust manifold causing the high EGT's. Same way people spool there turbos with lots of timing retard which causes high EGT's for a couple seconds as the gas is burning in the manifold.

might be your timing then? or let's say, your timing kinda "burns" the probe

[jim34]

I bought it from some aircraft supply on ebay it was a great price like $35 said it was the highest rating of any type k whatever that ment class a or somthing like that.
Im running a swirl head with stock chambers and a s5 fwd cal with the fpr turned way down and I have a dynojet wideband mounted 18" from the turbo and I am seeing a few degrees of retard on the scanner said it was pulling a few degrees from #1 and like 1 degree from cyl 2-4 but I think thats false knock because of the fact i had race gas in it with no change and ive been beating this motor for a year and a half now
I wonder if your having an issue with one cyl not firing right and the others are making up for it on the wideband since they all mix together and maybe your not seeing the real afr.

Your egt should immediatly drop when you let off the gas, it should not rise

[BobsBlackACR]

Keep in mind that distance from the head is what will make the thermocouple vary from car to car. IMO as long as you have the ability to also keep track of AFR's and you're fine there, then as long as your EGT readings are consistant, you should be fine.

FWIW, the closer to the combustion process you get the hotter the EGT readings should be. I mean at your tailpipe it what, maybe 200 degrees (if that) under full load? But most dont know that cylinder temps can momentarily (for a few milliseconds) exceed 3000 degrees. There is obviously an immediate cooling process that takes place between then, and the time it takes to go through the exhaust system.

$.02

[The Pope]

all 4 cylinders may not be 11.5:1 AF. The wideband and the EGT both read the whole engine. One lean cylinder can throw off the EGT.

Otherwise I would lower you timing a bit or your static compression. G head or a cal adjustment. Another way is bleeding off some cylinder pressure. With your mods you may not need to run a super tight 89 cam, try letting a little more air through.

[speeduphoria]

well the wideband is reading the entire motor and the EGT probe is only reading cyl #4

Upon recent research by myself I've found that EGT is basically useless. Now if you have 4 EGT probes(each cyl) then it is more help. But due to variances from motor to motor among other variables it doesnt mean much. if you have 4 probes then you can tell air flow and fueling differences from cylinder to cylinder, which unless you can tune individual cylinder ignition timing its kinda pointless also, but you could possibly switch injectors to even the fueling out some.

People w/ 2.5 g-head setups have a hard time keeping below 1700deg, they add timing till it pings and still high EGT's. So could be the cam timing/cam profile or other. They would run these 1700deg EGT's on stock cast pistons and never have problems with anything melting

Basically to use 1 EGT probe, get on a dyno and note the EGT for most power w/ A/F in a safe range. Then if you tune further on the same setup you can tune for that EGT(meaning max power). If you change anything then your EGT will be different again.

I have 2 EGT probes, #1 & #4, I datalog from cyl 4, now I still dont look at this while driving but mine also stays in check. If I had to do it over I would not even bother with EGT probes as they are somewhat meaningless. on my Logs the EGT still rises for almost 1 second after I let off, then fall, I think this is acceptable response time. This is a thick probe that does not taper to a point at the end.

[turbo minivan]

ive run 32psi with alcohol, pump gas and stock 12* timing at 4500* on the street with no problems.

[Dean Stillie]

I have found with the 8v head running as high as 40 psi boost egt's were always approaching 1700 degrees buy the end of the run. Probes in one and 4. Then with the same efi system cal turbo, injectors but with a 16v head egt's would be 1440 any higher the car was so lean it would hesitate.

[ATaylorRacing]

Hi Gang, I just had my digital EGT gauge put on my BONE stock SRT4 this morning and then proceeded to blast down the interstate at 120 mph+ and about crapped when I saw the gauge hit 1550! On my old carb Matchbox I would have already slowed down due to four pistons turning into liquid! I put the gauge on it because a bit later in the month we are doing a stage 2 set up, Mopar exhaust, CAI, and some leaning ouut of the system...wanted a base line. I guess these cars are a lot different than our old school cars.

[lametec]

My Daytona ('89 2.2 TII) regularly went over 1600° on a WOT run when running 16+ psi. Usually by the time top of 3rd gear came around, it would be around that point. Never melted any pistons. I have an EGT probe in each cylinder.

[acannell]

got my exposed tip probe installed. bought crimp pins from mouser so I could use this new probe with my existing autometer cobalt series EGT gauge. works like a champ. the needle responds fast enough to drop 200 degrees during shifts. THIS is how its supposed to be.

wow I wonder how much EGT information out there is totally wrong because people are using numbers from slow gauges and probes YIKES.

[janus]

would you let us know which probe you are using and exactely how you installed it?

how much is your peak EGT° now?