EGT temps for 1FZ turbo engines.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

jjdeneen918

SILVER Star
Joined
Jul 23, 2008
Threads
84
Messages
1,194
Location
Long Beach, CA
I would have inquired in the turbo gauges thread, but Wits End pissed everyone off & all the comments to that thread derailed it & it is now locked.

Anyways, currently running the JRP 14in1 gauge in the LX450 with the turbo kit that’s now gone extinct.

What would be an ideal temp setting for the alarm feature on this gauge.

I have EGT running behind my AFR reading.
So I’ll only see EGT temps if they go over a certain programmable temp threshold.

It’s currently set at 1,950 degrees F. I’m currently running very rich, so I’m getting temps pretty high at a few seconds at a time. That all is being discussed in my thread “Under 8 MPG”.

Question is too low, too high? What is a normal range & what is considered hot & too damn hot?

IMG_4641.jpeg
 
way too hot, your gonna damage something id think...
id guess thats a byproduct of your 'too much fuel' 8mpg issues
 
I don't let my Supra get over 1600°F. You're gonna melt pistons at those temps.
 
wont be too long till it turns into a forge
 
I would have inquired in the turbo gauges thread, but Wits End pissed everyone off & all the comments to that thread derailed it & it is now locked.

Anyways, currently running the JRP 14in1 gauge in the LX450 with the turbo kit that’s now gone extinct.

What would be an ideal temp setting for the alarm feature on this gauge.

I have EGT running behind my AFR reading.
So I’ll only see EGT temps if they go over a certain programmable temp threshold.

It’s currently set at 1,950 degrees F. I’m currently running very rich, so I’m getting temps pretty high at a few seconds at a time. That all is being discussed in my thread “Under 8 MPG”.

Question is too low, too high? What is a normal range & what is considered hot & too damn hot?

View attachment 3621816
Great topic, AFR plays a huge factor here.

Same principle different application, aircraft turbo charged piston engines.

The location of the probe / probes plays a part, we measured Manifold pressure fuel flow GPH, RPM, to determine percentage of power. Anyway best power occurs 125 degrees Rich of peak EGT, has the nose cylinder pressure and hi CHTs. Now peak egt dependent on altitude and temperature ect near sea level it was as high as 1550-1700 egt normally on most turbo charged aircraft engines but flown TIT near the turbo. Best cooling of cylinders same altitude flat out occured 200-225 degrees rich of peak. Hi power full throttle power, if the pilot didn’t run these engine with these things in mind cylinder cracking can occur. Once you in cruise you couldn’t make peak egts at lower available power settings. Therefore cruise egt would be 1400 ish degrees 1200-1250 at the cylinder heads ports, was good hi power. Now your question is a max egt, if compared to aircraft engines, where is the temp probe,

If your AFR is correct, .80 less Lambda under hi power Wot , egts should take care themselves and monitor that temp as a possible limit maybe 50-100 higher. Once engine power is down and engine feed back closed loop operation is occurring, 1.0 lambda average 14.7 AFR gas not ethanol it like airplanes will be lower.

But it not bad to watch egts, I would be more concerned of AFR at hi power settings. It’s a main component of EGT “mixture” as you add more fuel under high power it cools the egt, That simple. gas turbo engine, not diesel.

Components I would image high temp limits, aircraft was 1750 degrees was for a higher quality exhaust and 1650 was lower stock exhaust piping.
That temp was taken at the turbo inlet exhaust side.

It temps taken at exhaust ports was lower. Mutable probe egt engine Monitor we used.

I gave theory here, gas turbo charged engines. Aircraft we control the mixture manually to account for altitude and different power settings.

11.8- 12.5 AFR gas, runs great best power until it melts something. Hence 125 Rich of peak hi power hi cylinder pressures, ect … avoid that when Open loop under hi power is my recommendation.

There is a conversion for GAS to Lambda my AFR gauge does it for me. Boosted Supercharge 100 series intercooler v8 4.7. I keep it in lambda since I use premium fuel and E85. When boosting I keep an eye on Lambda AFR make sure wot hi power Atleast .80 or lower.

Hope it helps or was totally confusing.

Take care

Tex
 
I’m in need of replacing this gas temp sensor.

Anyone know if the sensor could be sourced locally or is the sensor exclusive to JRP?

I’ll ask here first before waiting on an email reply from JRP. I’d like this fixed this week, can’t imagine waiting on a sensor from AU, would be shipped overnight.
 
I’m in need of replacing this gas temp sensor.

Anyone know if the sensor could be sourced locally or is the sensor exclusive to JRP?

I’ll ask here first before waiting on an email reply from JRP. I’d like this fixed this week, can’t imagine waiting on a sensor from AU, would be shipped overnight.
My guess is it's a type K thermocouple. That is the style used by most egt gauges and after a quick search most type K probes are very close to the data that they have on the website. Whatever you order match the length of wire that is currently there. Resistance matters in this situation.
 
JRP was quick on the email response. I ordered this. $33 sensor, but $20 to ship, from Australia. So expensive & probably longest possible way to order, but 100% correct part for my application I guess.

IMG_0393.png
 
I have the same turbo kit and gauge - been running it since 2020. I'm now working with JRP to figure out a warning I'm getting on the display for High EGT. I dont have the EGT sensor plugged in. The warning, when it happens, its popping up over the AFR readout. The EGT warning kicks on around 1400 F and I've seen it climb to 1650 F. - that's when I pulled over and let it cool.

JRP sent me instructions for a hard reset thinking perhaps theres a fault that needs to be cleared - I've also just replaced the wideband O2 sensor seeing if that would fix the issue - it did not.
*** @jjdeneen918 - Question is what is the proper temp to set the EGT temp warning to for the same turbo set up you have / what did you land on?
Thank you
 
I have the same turbo kit and gauge - been running it since 2020. I'm now working with JRP to figure out a warning I'm getting on the display for High EGT. I dont have the EGT sensor plugged in. The warning, when it happens, its popping up over the AFR readout. The EGT warning kicks on around 1400 F and I've seen it climb to 1650 F. - that's when I pulled over and let it cool.

JRP sent me instructions for a hard reset thinking perhaps theres a fault that needs to be cleared - I've also just replaced the wideband O2 sensor seeing if that would fix the issue - it did not.
*** @jjdeneen918 - Question is what is the proper temp to set the EGT temp warning to for the same turbo set up you have / what did you land on?
Thank you
So it’s been several months since this happened to my rig.

I upped the temp value “temporarily” to keep the audible alarm from going off constantly.

I did purchase a new wide and O2sensor from JRP.

I since discovered I was running super rich due to a collapsed vaccum hose & the MAF sensor was bad too.

I’ve since corrected those issues, rig is running perfectly.

BUT, I never did get back to replacing that sensor or adjusting the temp value back down.

I forget what the temp was originally set at, I’d have to do some research for our engines to determine that again.

Sorry I’m not better help at the moment.
 
So it’s been several months since this happened to my rig.

I upped the temp value “temporarily” to keep the audible alarm from going off constantly.

I did purchase a new wide and O2sensor from JRP.

I since discovered I was running super rich due to a collapsed vaccum hose & the MAF sensor was bad too.

I’ve since corrected those issues, rig is running perfectly.

BUT, I never did get back to replacing that sensor or adjusting the temp value back down.

I forget what the temp was originally set at, I’d have to do some research for our engines to determine that again.

Sorry I’m not better help at the moment.
Which hose was collapsed and where is that?
Thnx @jjdeneen918
 
Last edited:
This high EGT warning is new within the last two weeks. Rig has ran perfect since 2020 with no issues. Im miffed
 
From what I recall…

It was a vacuum line related to the fuel pressure or fuel rail somehow.

A wire had pulled away from the harness for the MAF & it was cleaned too.

I had Topline in Huntington Beach diagnosis & make the repairs.
 
From what I recall…

It was a vacuum line related to the fuel pressure or fuel rail somehow.

A wire had pulled away from the harness for the MAF & it was cleaned too.

I had Topline in Huntington Beach diagnosis & make the repairs.
Hey just to note, if fuel pressure regulator is plumbed to intake it vacuum at idle and low throttle applications and while boosting it raises fuel pressure to enrichen fuel mixture when boosting. Normal fuel pressure regulators should raise 1 psi per 1psi boost. Some aftermarket ones can raise 3 psi fuel pressure to 1 psi boost. This pressure raise to needed to maintain a differential pressure across the injector. When boosting.

This vacuum line collapsed it would have higher fuel pressure idle to zero boost and leaner mixtures under boosting and can cause higher egts. As you past 12.5 AFR to richer side of peak egts will start dropping , called fuel cooling. You want that when boosting. Depending on amount of boost your needed AFR could be as rich as 10.5 or in the 10’s for best cooling.
AFRs in the 12’s isn’t good boosting for cooling and cylinder pressures. Everything has to be just right or engine damage can start happening

Take care
 
Test run last evening shows I was successful. EGT warning did not appear. Cleaned the air filter / MAF / and changed out the O2 wideband sensor. JRP sent me instructions on how to do a hard rest for the control box, which i haven’t done. If youd like those instructions let me know and ill share - just to have. Anyhow - appreciate you guys
Other thing to ask - the Tial blowoff valve hose - can that vent into open atmosphere? I had mine originally tucked into a rubber grommet in the firewall and noticed it had worked its way out.
Does that even matter per this set up?
Ive had other turbo vehicles and it didnt matter
 

Users who are viewing this thread

Back
Top Bottom