just got my egt gauges installed a few months ago and noticed im getting some pretty high egt readings under boost. seeing anywhere from 1600-1900* f by end of 4th gear

setup is:
s5 streetport
t61 running at 16 psi twin scroll with twin scroll fd manifold
3"down pipe with no cats
greddy heat range 10 plugs on stock fc coils with hks twinstrike
m2 pre turbo and m10 post straight water with 150 psi pump
denso fuel pump with base pressure at 40 psi
mid to low 10 afrs (93 octane)
leading is 13* if i remeber and 10 split

im using a lc1 wideband with a heatsink, im wondering if maybe my sensor could be reading off or what. at cruise i get about 1500*f at 14.7 afr, not sure if that helps or not. i havent upped the boost yet or dynoed because im afraid of the really high egts especially since im shooting in so much water.

im using an fittings and braided lines for w.i. system as well so i eliminated any leaks there. its progressive as well, start at 7 psi and max at 15

 

What are you using for engine management?

Sounds like your timing may be retarded to much which I believe would cause EGT's to rise even at such a rich A/F.

 

oops haltech e6k

 

it is most likely a calibration issue. i suggest you re-calibrate your timing to make sure it is really on the mark.

normal peak EGTs should be no more than 1750. they can be around 1550 if everything is correct.

your settings, 13/10, are fine at 16 psi... the question is, are they accurate.

howard

 

do u think it could be more of a wrong o2 reading or timing issue howard?
and how can i recalibrate timing?

 

since you are running in the 10s AFR-wise i would look at the plugs and confirm you are not very lean. at 10 your plugs should not look tan.

pull a lower plug and post a picture and i am sure you will get good feedback from others.

once you have confirmed that your AFRs are about correct, that you are not super lean, it would be time to focus on the ignition timing.

i don't know how Haltec's work but on my ECU i just change the map so it is all 15 degrees. i find 15 on the crank pulley, hook a timing light to L1, start the motor and check to see the light is on the mark. make sure to do it up the rpm scale as there is always the possibility of higher rpm drift off the mark.

howard

 

Lock the time timing to -5 in Setup -> Ignition Setup. Verify the leading spark plug is hitting the correct mark on the pulley with a timing light.

thewird

 

Where are you taking these readings? pre or post turbo?

Also howard, what are your egts while crusing in 5th at 70-80 mph? At idle as well?

 

readings are pre-turbo. readings post turbo are very close to useless as the relationship between pre and post changes w load.

so you can't just add X to derive pre from post.

from my logs a week ago:

idle at 980 rpm preturbo EGT is 854 F

steady TPS at 2800 down the road EGT is 1150 F (-7 psi)

hc

 

another area that fits in the "useless" (well almost) category are gauges.

w re to EGTs you want logged data on an X Y grid that you can lay up against various other readings. it is extremely difficult on a run to watch a fast moving gauge.

 

Yes, you need to read thermocouple data in realtime. The AEM 4 channel thermocouple amplifier can convert thermocouple data to an analog signal that you can log.

It's always a good idea to verify your base timing is correct in the Haltech.

Post data logs of these pulls and post your timing maps (screenshot so everybody can see it).

 

I was asking, I figured maybe you were reading post turbine. My sensors sit about 2 inches from the exhaust port.

I see similar idle temps, around 900-1000deg at around 1000rpm idle.

But steady state cruise(70-80mph) I see around 1400 to 1500degrees with a/f in the 14 range. Simliar to the op. Holding steady speed the gauge doesn't move much. Don't need to log to see this on a 6 1/2 hour road trip. I can add fuel to cool things down a bit but MPG suffers.

Just curious how you are coming about getting 1150 steady state. I have played with all sorts of timing maps and a/f mixtures and have never seen temps close to 1150 @ 70mph in 5th gear

I know of someone that does log egt and his readings were similar to mine. Plus his egt at the end of a boosted run(7000rpm) were 950c or 1750f.

 

here's an EGT chart from my Jan 16 run. 514 hp at 23/24 psi. the motor suffered a backfire (see the outlier reading at P20) but still kept running.



i am especially happy re the EGTs given the motor was really cranking. it ran to 8650 and unfortunately i hadn't re-scaled the RPM range which ends at 8000.

there are a lot of factors that can influence EGTs... some software and some hardware.

also, the numbers at 2800 were in 4th not 5th.

howard

 

timing w 11 split in boost...



P7 is crossover between vacuum and boost. peak torque 6450.

i may be a bit advanced on the timing V other maps since 30% of my fuel was methanol.

howard

 

That makes a little more sense. Re cal the map, have mine to 8800 and it nice to make adjustments up there.

One other question, what are your egts at a steady cruise and 70-80ish,5th gear?

BTW- glad to see you are back with the turbo test. Thanks for sharing your knowledge, always a good read.

 

interesting

 

Im sorry been away for a few days. I will pull plug and get a pic. The temps are preturbo and are about 2" away from exhaust port.

 

Forget about trying to read the plugs unless you done a plug chop with new plugs at full load where your suspected issue is. You can be extremely lean at full load but fat at idle, as soon as you come off the throttle the plugs will color up. Unless you do it right, you're wasting your time at best and providing yourself with false information at worst.

 

what is the A/R on the exhaust side of the turbo?
what are the EGT's on low boost say around 7psi with no water
how old is the wideband sensor and was it recently calibrated

cheers

Lance

 

Think ar is 1.00
Calibrated 02 out of exhaust, I have not tried lower boost without water. Im afraid to turn off water in case something is wrong heh

 

got a pick of your manifold by any chance ? Ive got a similar turbo and 44 tial WG and over boosting something chronic

 

I had same problem. I went with jgs 50mm and port wg runner hole some and creep went away

 

i havent forget just been trying to get a working laptop. have stayyed of hitting it hard because im afraid of hurting my seals.

im runing a rewired supra pump,can it be im running out of pump?

 

here is a datalog for it.

 

opps here it is, error on above post ha