EGT probe and Megga Squirt?
Turbo Mini Forums

can it be done easily and cheaply? if not ill do a stand alone job

thinking about adding an EGT probe to the center runner just after the head

itld be nice to have it log in MS

This circuit will allow you to connect an EGT probe to a free ADC input (ADC6 or ADC7): http://www.msextra.com/doc/ms1extra/MS_Ext..._Manual.htm#egt

That's from the MS1 doc but that will also work on an MS2 or MS3.

Note that the amplifier chip is somewhat expensive. And you can use the AD595AQ instead of the AD595CQ.

http://www.jbperf.com/

ive got two wide bands and an oil pressure log on both those inputs already : /

I might be wrong but I thought you had an MS3X card as well as the standard MS3 ???

If so it has another three analogue (0-5V) inputs or are you already using them too ?

The circuit Jean mentions just turns a thermocouple's very low voltage into a 0-5V signal.

If you've used all the available ADCs (analogue inputs) the simple solution, if you want an integrated setup, is to use one of Jean's IOx boards.
That's what myself, a couple of others on here, and lots of people who use Megasquirt do, and that gives you lots of additional inputs and outputs.

Schrödinger's cat - so which one am I ???

Can the MS read from Innovates serial stream ?

If so the Innovate TC-4 is handy, it'll do 4 thermocouples.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

http://www.jbperf.com/

My first thought is "why?".

In the early days, I had thermocouples on the manifold and on the cylinder head and logged lots of useless data.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

is egt not as inportant on a "petrol" engine i know that EGT and wide band are inportant on turbo diesel stuff just just assumed it was that same :/

Go back and find Paul's data... When you have twice as much exhaust going through the centre branch, it runs hotter so makes comparing the inner vs outer difficult / impossible. While you will see patterns, interpreting them would near impossible without already knowing what they mean (i.e. having 2 lambda sensors already plugged in there).

Having said that, SC used 3 thermocouples and suggested the data was useful.

Edited by PhilR on 29th Feb, 2016.

The centre port runs slightly hotter, but the fact that the thermocouple gets has two doses of exhaust gas per cycle means that it reads considerably hotter, around 120 Deg C on my engine.

Then you have to consider that the EGT is hottest around stoich and falls either side.

I've never been able to reconcile what to do with the data, other than to verify a simulation.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Work out how to get a thermocouple in each cylinder, and that would be interesting.

I think a lot of my original data plots have dissapeared, so here are some interesting sets of data:

Datalog from 2009, uses the Innovate TC-4 and MTS datastream, NA 998 before fitting the turbo and the code was still in the development stage but you can see the big difference in inner and outer EGTs.


Data from a simulation, this time a turbo 998 but shows the reasons for the big difference:

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

How useful did you find CHT Paul?

Useless, too much delay.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

well my thought for the EGT was to check i was not going to melt stuff really as far as alcohol fuel and boot ive been told that its possible to get it to hot with certan lambda ratios and timeing

for me its really just going to be one probe in the center branch the "hottest" and just to check it not getting to hot.. apart from that its not unlike wanting to know your coolant temp really

so what can i call a safe number to stay below for a second peak and also for a min or so power run

on my turbo diesel i run it at 750c for the most part when at 28-30 pound and it climbs to nearly 950c if i keep the the hammer down when up in the rpms where it boosts to around 37psi but i rearly punish that hard only when on the free way over taking and drag racing mates most of the time its cruseing around 13 pound and 350-400c big 600x300x76 front mounted IC intake air is mostly near ambint when cruseing and gets up to nearly 45c under short bursts and 60c if im pushing it hard its a chinese turbo that cost 230 aus..

any ways what should i look for as "safe numbers" for the mini about the same? what paul s has shown 800c ? 1300C? alu melts some where around 650C right? altho its only "hot" for a split seconds then has the intake to cool it off again so?

not so worried about the turbine as its way down stream the temp will likely be a bunch lower there

'Safe numbers' are only relavent to a particular engine. There are so many variables that affect it, you can't compare across different engines. Also, diesel runs cooler, and ethanol hotter (?). Even if you had the same engine spec as Paul, different ignition timing would also give you different temperatures.

I'm not saying "don't do it", but just know the results may not be that useful.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Swiftune just posted this picture on Facebook:



Very interesting.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Grab the toasing fork!!!

That looks like not only is it way too lean or retarded but that there's a distinct AFR mismatch between inner and outer cylinders.

http://www.jbperf.com/

Yes i moved to the darkside

Instagram @jdm_brett

Or it's showing they forgot to fit the turbo !

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

I don't think that the difference in LCB leg temperature is anything to do with AFR imbalance, if there is any.

More differences in VE and carry over of fuel on overlap.

Even though the centre LCB leg looks hotter at the head flange, it quickly cools whereas the outer cylinder leg gets hotter!

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

http://www.jbperf.com/