Diesels - ECT vs EGT vs AFR ?? (1 Viewer)

[ATL Cruiser]

I'm about to finish this 1HZ turbo install and start cranking up the fuel pump.

Coming from the world of gassers, all we ever watched is Engine Coolant Temps and Air Fuel Ratios. That was how we knew if a head was about to blow or internal catastrophic damage was about to ensue.

EGT is a new one for me. I'd never seriously considered exhaust temps until starting this turbo install.

So that brings me to the question - do diesel guys watch ECT? If a good pre-turbo EGT gage is installed, is there any value in watching ECT or is it just redundant?

 

[Dougal]

Indirect injection engines like your 1HZ put more heat into coolant. So you will have to watch coolant temps under sustained high load (i.e. sand driving).

EGT is directly related to intake temps, injection timing and A/F ratios. Keep them all safe and you're good.

Your 1HZ was not designed to be a turbocharged engine. So keep boost sensible and A/F lean. An A/F gauge is actually better for tuning vs EGT as many people install EGT in the wrong place with probes too short. Tune for 20:1 min A/F under load and you should be okay.

 

[Dusten]

I'm about to finish this 1HZ turbo install and start cranking up the fuel pump.

Coming from the world of gassers, all we ever watched is Engine Coolant Temps and Air Fuel Ratios. That was how we knew if a head was about to blow or internal catastrophic damage was about to ensue.

EGT is a new one for me. I'd never seriously considered exhaust temps until starting this turbo install.

So that brings me to the question - do diesel guys watch ECT? If a good pre-turbo EGT gage is installed, is there any value in watching ECT or is it just redundant?

Big power gassers watch egt too.

 

[ATL Cruiser]

Indirect injection engines like your 1HZ put more heat into coolant. So you will have to watch coolant temps under sustained high load (i.e. sand driving).

EGT is directly related to intake temps, injection timing and A/F ratios. Keep them all safe and you're good.

Your 1HZ was not designed to be a turbocharged engine. So keep boost sensible and A/F lean. An A/F gauge is actually better for tuning vs EGT as many people install EGT in the wrong place with probes too short. Tune for 20:1 min A/F under load and you should be okay.

@Dougal thank you for this. I also read your entire thread on "how much boost can a 1HZ handle?" Tons of insight in there. Good stuff.

I'm working on sourcing a diesel AFR gage. Seems that most gages top out at 22 AFR. This 1HZ will hit 100 AFR at idle. Do you have an AFR gage you like?

' ISSPRO : auto / marine / diesel gauges, sensors, kits and instrumentation - https://www.isspro.com/products.php?productid=3597

 

[Dusten]

@Dougal thank you for this. I also read your entire thread on "how much boost can a 1HZ handle?" Tons of insight in there. Good stuff.

I'm working on sourcing a diesel AFR gage. Seems that most gages top out at 22 AFR. This 1HZ will hit 100 AFR at idle. Do you have an AFR gage you like?

' ISSPRO : auto / marine / diesel gauges, sensors, kits and instrumentation - https://www.isspro.com/products.php?productid=3597

View attachment 3162525

The issue is scaling. A wideband sensor is 0-5v

So for a gauge with a wide spectrum you lose fidelity.


The wideband in my lightning is 10-17 and is highly accurate because of it.

 

[KiwiDingo]

The latest Wideband O2 sensors available in diesel AFR gauges are very accurate and can read up to and over 120:1 depending on brand.

 

[ATL Cruiser]

The latest Wideband O2 sensors available in diesel AFR gauges are very accurate and can read up to and over 120:1 depending on brand.

I'm having a tough time finding some. Could you hit me with a few brands?

 

[Dusten]

The latest Wideband O2 sensors available in diesel AFR gauges are very accurate and can read up to and over 120:1 depending on brand.

I didn't say they were inaccurate. I said they lack fidelity.

 

[KiwiDingo]

I'm having a tough time finding some. Could you hit me with a few brands?

I'm using an Innovate AFR gauge as I can source them easily. Unsure what's available in your area? But with the digital display is very easy to see any AFR from 0-120:1. My FT actually idles leaner than 120:1 so goes off the scale but when A/C kicks in it drops back down to around 110:1. It's so responsive and accurate in displaying the AFR that I can easily see what effect small changes to the compensator pin profile has during spool as the pin moves through its travel.

 

[KiwiDingo]

I didn't say they were inaccurate. I said they lack fidelity.

Unsure what you're on about mate, I was replying to wesdaniel post.

 

[Dusten]

Unsure what you're on about mate, I was replying to wesdaniel post.

Your reply was directly under mine and was a long the same lines. Because you hadn't quoted him I took it as a reply to me.

 

[ATL Cruiser]

I'm using an Innovate AFR gauge as I can source them easily. Unsure what's available in your area? But with the digital display is very easy to see any AFR from 0-120:1. My FT actually idles leaner than 120:1 so goes off the scale but when A/C kicks in it drops back down to around 110:1. It's so responsive and accurate in displaying the AFR that I can easily see what effect small changes to the compensator pin profile has during spool as the pin moves through its travel.

Thank you. Innovate is exactly who I was looking at. Their Products website is currently down, so I'm waiting for it to come back up.

I currently have their handheld AFR gage, and it works great. Looking to add an AFR gage to my pillar pod now.

 

[JDM Journeys]

@wesdaniel with respect to egts... I found way back when I first started driving small turbo diesels, that they acted opposite to what I thought. Higher revs should mean hotter? Not colder? But driving in the Rockies AND towing got me very quickly figuring out what worked and what didn't.

High egts can be usually lowered by dropping a gear (if auto then def out of o/d). I guess this should be intuitive since you're evacuating gasses faster, but it didn't make sense to me at first.

In terms of gauges... I've had a few different types, but my favorite is my digital auber instruments. Even avail in 24volts! It's mounted on top of my steering column so very visible.

 

[Dusten]

@wesdaniel with respect to egts... I found way back when I first started driving small turbo diesels, that they acted opposite to what I thought. Higher revs should mean hotter? Not colder? But driving in the Rockies AND towing got me very quickly figuring out what worked and what didn't.

High egts can be usually lowered by dropping a gear (if auto then def out of o/d). I guess this should be intuitive since you're evacuating gasses faster, but it didn't make sense to me at first.

In terms of gauges... I've had a few different types, but my favorite is my digital auber instruments. Even avail in 24volts! It's mounted on top of my steering column so very visible.

High egts are caused by more fuel than air. That's why lugging causes egts to jump and dropping a gear lowers them.

 

[ATL Cruiser]

@wesdaniel with respect to egts... I found way back when I first started driving small turbo diesels, that they acted opposite to what I thought. Higher revs should mean hotter? Not colder? But driving in the Rockies AND towing got me very quickly figuring out what worked and what didn't.

High egts can be usually lowered by dropping a gear (if auto then def out of o/d). I guess this should be intuitive since you're evacuating gasses faster, but it didn't make sense to me at first.

In terms of gauges... I've had a few different types, but my favorite is my digital auber instruments. Even avail in 24volts! It's mounted on top of my steering column so very visible.

Thank you. Good insight on the Auber gauges. I didn't realize they made a 24V version.

I've been thinking a lot about the "approved" tuning method for these engines. Essentially it is fully loading the engine and checking AFR and EGTs at 1000 and 3000 RPMs. This would simulate a worst-case condition of towing and/or driving up a long, steep incline.

Tuning via this method keeps the engine safe even when those condition are met BUT it means that the engine is weaker in all other scenarios.

 

[Dougal]

I have an innovate motorsports gauge, I think this is it: MTX-L PLUS: Digital Wideband Air/Fuel Ratio Gauge Kit (3 Ft.) - https://www.innovatemotorsports.com/mtx-l-plus-digital-wideband-air-fuel-ratio-gauge-kit-3-ft.html

Runs down to 100:1. I have it setup on a cigarette lighter plug and exhaust clip-on section so I can swap it from vehicle to vehicle.

 

[svsisu]

x2 on Auber gauges, I've been very pleased with my 24v versions from them- using for coolant, EGT, and boost.

 

[Morrtac]

I'm about to finish this 1HZ turbo install and start cranking up the fuel pump.

Coming from the world of gassers, all we ever watched is Engine Coolant Temps and Air Fuel Ratios. That was how we knew if a head was about to blow or internal catastrophic damage was about to ensue.

EGT is a new one for me. I'd never seriously considered exhaust temps until starting this turbo install.

So that brings me to the question - do diesel guys watch ECT? If a good pre-turbo EGT gage is installed, is there any value in watching ECT or is it just redundant?

If you or anyone else is looking for afr gauge or great gauges for diesel check out www.justraceparts.com.au . I about to pick up their stuff for my 1KZTE Prado.