Failsafe Pt2: 4 Channel EGT

[bigBADbenny]

In Part One (yet to be summarized) I researched the best bang for buck AFR gauge and decided on the AEM 30-4900 Wideband failsafe to monitor boost and AFR, and more importantly, to provide a failsafe for overboost and AFR out-of-range conditions, both of which can occur due to mechanical failures, events as slight as loose vac hoses and related items.

I began to research other avenues for protecting my investment from self destruction, wilful or otherwise.
I had been aware of the term EGT, but had ignored it due to concentrating on AFR, which seemed to be somewhat more important as regards safety during E-tuning (AKA remote tuning).

At the same time I was researching the value proposition in street engine rebuilds and came across the Outfront Motorsports Closed-Deck Torture Test post on Nasioc.
In order to prevent another meltdown of their built for high boost motor, a 4 channel EGT kit was installed, in order to monitor individual Cylinder Head Temperatures and or Per Exhaust Runner temps. Overkill? Maybe, but I like overkill.

From research it appears that the major sources of 2.5T failures are related to uneven or out of control Cylinder Head Temperatures.
Specifically head gaskets, ring lands, pistons, and bottom end bearings.
Given the possibility, or likelihood even, of uneven external heating of engine components, uneven fuel delivery due to the configuration of fuel lines, fuel rails and injectors, stock or aftermarket, and the ability to adjust per cylinder trim in the tune makes 4 channel EGT monitoring an attractive proposition.

In this thread I intend to look at some of the kits on the market that allow quad channel (or per runner) EGT monitoring, the options available for gauges with peak hold, warning and logging of the output and the possibility of extending the failsfafe function employed by the AEM to EGT.
Recommendations for the install of the sensors and the gauges will be covered.
This post will be modified and corrected as we uncover more related information.
I'll be linking the sources of information and looking for a solution with a budget of $500 installed.

This thread got me thinking: Outfront Motorsports Closed-Deck Torture Test
Nasioc: Per Cylinder fuel comp. - Lets Discuss.
Food for thought: 4 channel EGT temps-WOW
Crucial reading: Relationship between knock, AFR, timing, and EGT?
Post 55 here amongst others: Please expain to me why 1600 degrees F is the magical number
Good read: EGTs 101/501
IWSTi: Defend against Knock

[bigBADbenny]

Available 4 Channel EGT Kits:

Auber single channel K type thermocouple pyrometer (x4)

Auber Instruments Manufacturer Site
eBay DIGITAL EGT THERMOMETER PYROMETER w/ RETRANSMIT & ALARM
Pros: Low cost, digital display with peak hold, warning/failsafe output, 0-5V output for logging, compact size, gauge colour options.
Cons: max 4x samples per second (not sure if this is an issue)

^ This is the solution that I'm most interested in pending more research and feedback.

AEM 4-Channel K-Type Thermocouple Amplifier
Pros:
Cons:

Innovate TC-4 4 Channel Thermocouple Interface
Pros: Integrates with the Innovate Modular Tuning system
Cons: as above.

4-Channel EGT Digital Pyrometer Gauge + Probe Kit
Pros: Low cost, digital display with peak hold, warning/failsafe output, compact size, gauge colour options.
Cons: max 4x samples per second, need to confirm if it can be logged.

DIY: Autospeed Tempscreen EGT
Pros: Do it yourself is fun...
Cons: Component cost is higher than available kits (Auber), extra features like logging and peak hold may add too much complexity.

Alternatives:
AEM 4-Channel Wideband UEGO Controller
Pros: monitor AFR's on each runner pre-turbo
Cons: price is around double a basic EGT kit once 4x probes and a post turbo pressure sensor is included.

Old School: as outlined in one of the linked threads, checking CHT's by looking at the plugs.
Pros: Do it once do it right. Nothing to install apart from new plugs.
Cons: Requires several sets of plugs. Not an ongoing failsafe solution.

Water/Meth Injection.
Pros: Protects from detonation. Cleans carbon deposits from the combustion chamber. Can have failsafes incorporated. Can be a headroom or power adder.
Cons: Complexity of install, issues with tuning with the stock ecu?

[bigBADbenny]

Reserved for bung install research.
I have a nice set of SS EL headers awaiting bungs and wrap
Here are photos of the headers used in the OutFront Nasioc build:

Custom KilleBee EL for stock location rotated turbo w/ vee band up pipe.


ETS custom big runner EL low front/side mount with twin EWG/twin outlet.

On both sets of headers near to the exhaust port flanges, the big bungs are for 4 channel AFR, the much smaller bungs are for the 4 channel EGT sensors.

Since I'm doing a budget version and already have post turbo AFR, 4 channel EGT will have to suffice.

The aim is to get the EGT sensors placed on the runners within 3" from the flanges but more specifically: at an equal distance from the exhaust valves themselves.

Since on each head, the front and rear exhaust ports differ slightly in shape or length, then ideally one EGT bung will be arund an inch closer to the flange than the other, something which can perhaps be seen in the placement on the ETS headers.

[bigBADbenny]

2nd post edited! Bump for feedback/comment.

[bigBADbenny]

I've been to the Auber Instruments site and the entire kit with all the fruit including 0-5v output, 4M sensor cables and SS weld in bungs...
is around USD $440 delivered...

I'm just trying to establish the best method to log the 4x 0-5V outputs in RomRaider logger.

[<GB>]

Sounds good and im very interested in seeing the results this brings, I want new headers at some stage so might be an option to set this up the ceramic coat them

[bigBADbenny]

The rationale is simply increased confidence at higher boost levels.
Over limit EGT would indicate either a too rich or lean condition and or a turbo operating over its surge limit.

IMHO a fully built engine (like yours) would justify 4 channel AFR as well .

[Boostaddict]

Some big dollars your talking here BBB??

But you know what, I get this!!

I've heard a few times that particular cylinders can be more prone to failure in the EJ's due to many reasons.

This would help control and hopefully stop a motor going boom.!!! Would have been good for my head issues as I'm sure there would have been differences in the side/cylinder that's lifted!!!

If you factor in the 4 channel EGT & AFR & the header & the ceramic coating / heat wrap ...... What are you at $$$$ wise??

$1,500-$2,000?? Dependant on the header I suppose.!

Not a bad idea tho when I go bigger turbo down the track.!!

Also, some aftermarket computers MAY have this input to monitor these perhaps !!! That would be awesome!!!

[bigBADbenny]

As stated, 4ch AFR is around $1k due to the greater expense of the sensors, amps and post turbo pressure sensor.
The plan here is to tune with post turbo afr and per cyl trim, monitor and failsafe with the 4ch egt.

The kits can be ordered with plain bungs if you choose to use your stock headers, further saving on cost.

[jaydece]

Some big dollars your talking here BBB??

But you know what, I get this!!

I've heard a few times that particular cylinders can be more prone to failure in the EJ's due to many reasons.

This would help control and hopefully stop a motor going boom.!!! Would have been good for my head issues as I'm sure there would have been differences in the side/cylinder that's lifted!!!

If you factor in the 4 channel EGT & AFR & the header & the ceramic coating / heat wrap ...... What are you at $$$$ wise??

$1,500-$2,000?? Dependant on the header I suppose.!

Not a bad idea tho when I go bigger turbo down the track.!!

Also, some aftermarket computers MAY have this input to monitor these perhaps !!! That would be awesome!!!

BBB? I understand the above idea and all? but I think for most of us? except for dr20t I believe this to be bit overkill?

why? cause please correct me if I'm wrong? But before spending $$$$ on temps, gauges and probes my 1st step in relation to what Dan said above is to run a parallel fuel system...and maybe a FPR to back it up?

just my thoughts people..

[bigBADbenny]

It was the experience of certain prominent members, and posts in built motor threads everywhere, that inspired this research.
Members that either went through numerous built engines, stock engines with power adding mods and tunes, both with and without supporting mods, and those that were unwilling to lean on their builds potential due to some unknown factor related to Subaru flat fours.
I beleive part of a solution is monitoring per cyl egt trim and monitoring.

[bigBADbenny]

BBB? I understand the above idea and all? but I think for most of us? except for dr20t I believe this to be bit overkill?

I did state in the OP that I like overkill.
I'm sure you can relate based on your experience in this field.

why? cause please correct me if I'm wrong? But before spending $$$$ on temps, gauges and probes my 1st step in relation to what Dan said above is to run a parallel fuel system...and maybe a FPR to back it up?
just my thoughts people..

I never stated that this was a step before other supporting or related mods.
I'm talking about both exploiting and protecting thousands of dollars of investment with some basic monitoring.


Regardless, from much research I can state that given the huge debate over the various approaches to fuel system upgrades concerning serial vs parallel, equal length lines, T vs Y joins and vapour lock etc; that having 4 channel egt would really give me peace of mind (being able to monitor if the fuel was indeed being delivered appropriately to each cylinder).

[jaydece]

I'm talking about both exploiting and protecting thousands of dollars of investment with some basic monitoring.

Ben? This aint no longer basic monitoring.... All good man! Keep up the good research and work

[jslayz]

I'm looking into 4 channel AFR at the moment, want to get car back for a while first.
Outfront builder has had to trim each cylinder so guess all of us will have to do this if wanting to increase reliability.
Side effect is more power, niiiice!

[bigBADbenny]

Outfront builder has had to trim each cylinder...

What are you referring to here?
An Outfront Motorsports turnkey built motor?
What trim? CC'd heads?
Intriguing!!!