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EGT measurement, probes, amplifiers, etc

cwdodson88

cwdodson88

Well-known member
Joined
Oct 27, 2011
Location
The Dalles, Oregon
Alright, so I literally blew a perfect 5/16" hole in my exhaust manifold.
<iframe width="560" height="315" src="https://www.youtube.com/embed/3I1jczE6IKI" frameborder="0" allowfullscreen></iframe>

So I'm in a perfect position to knock the other 3 plugs out and get some EGT probes in there. After looking at some amplifiers/datalogging stuff I have come up with a few options:

Innovate TC-4 and 1-4 K-type thermocouples. I was thinking that I could run one to a guage, probably runner 3, plug 1 and 4 and datalog off of runner 2.

AEM 4 channel K-Type and 1-4 K-Type thermocouples

a SymTech EGT interface and 1 K type and log with MS. Only problem is logging more than 1 runner at a time. But if I upgrade to MS2, I can log 2 at a time, and run 2 guages for the other and see any differences.

Any opinions out there?
 
cool, but not exactly in my budget to do all 4 at once.

Theoretically speaking, I could grab and Innovate TC-4, 1 thermocouple and 3 plugs, and plug it into my MS1 for the time being, and when I go to MS2 later in the spring, I can add a 2nd thermocouple to monitor the other bank (while staying alternating batch) and then when I decide to upgrade to sequential and COP, I can add the other 2 for individual cylinder trimming?
 
I'm using the 10 pack of egt probes from eBay for 40.00 with great success and the canegt
 
nathaninwa said:
I'm using the 10 pack of egt probes from eBay for 40.00 with great success and the canegt
Click to expand...

Nice! I'm hoping to do this in a staged configuration. Starting with only measuring 1 cyl at a time, then 2, then all 4, determined by funds. I would like to be able to log this with TunerStudio, and not have to use LogWorks for one and TS for the rest.
 
Well, you asked for options......

If you want to make life simple for your "staged" upgrade path, why not just construct the same thermocouple amplifier circuit used in the GPIO board for single sensor logging?

Seems kind of foolish to spend money on a product that isn't supported by the data collection you're trying to integrate into.
 
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gross polluter said:
Well, you asked for options......

If you want to make life simple for your "staged" upgrade path, why not just construct the same thermocouple amplifier circuit used in the GPIO board for single sensor logging?

Seems kind of foolish to spend money on a product that isn't supported by the data collection you're trying to integrate into.
Click to expand...

Yes I did, thanks for your input.

The reason I was thinking a prepackaged deal was to have less junk in my MS box, that way if some auxiliary crap bites it, I dont have to open the entire MS box. But you're totally right, Ive heard of people using the GPIO board for EGT, but I just havent looked around enough any documentation.

I do want to be able to log them together at some point, but cost is my limiting factor, spending $300 on a can-egt that simply will not work with MS1 would be worse of an option than having to use log works to datalog EGTs on the side while I log MS with MSDroid on the tablet or something like that.
 
it doesn't matter if you have MS1, 2, 3, pro, etc. You'll never be able to log anything from the innovate junk to the MS because there's no analog outputs to interface the EGT with the MS.

If you knew how to read, you'd find that I never suggested running the GPIO. The issue here is you're using cost limitations as an excuse to overlook the inherent limitations in the setup you propose that'll meet none of the criteria you've established as to how you want to integrate external data into the same log. It's just wasted money. I gave you a cost effective option that not only allows you to interface outside of the MS, but entirely integrates with your current ECU setup and is expandable as budget allows.

Learn how to read, comprehend, and how to look outside of your very narrow and distorted view of what you're trying to accomplish, then respond.
 
Gross Polluter, thanks for the input. Those had just been the options I found that fit my current budget. I was looking for advice and opinions, and stupidly, I didn't do much research before hand. I sincerely apologize for wasting your time. I'll just have to do better next time, I am only human.

What I'm am understanding, from your experience and Nathan's, is that the CAN-EGT works well and plays nice with the future plan. If I'm going this far, why mess around, just do it well once and go drive the piece. In order to do this, I need to upgrade to ms2. So, based on that, I must decide which limiting factors that I can remove. Easiest are my budget, and a staged installation. Thanks again GP, that's what I shall do. Cheap plugs, and a larger contribution to the car fund is what I'll do for the new year. If you don't mind, can I pm you for future advice on the subject of egt, and tuning with it?

I do still want to hear anything from anyone else in the mean time.
 
I was able to diagnose a top stumble, in high gear only and above 5500. The data told me otherwise, but when I brought up all 8 egt's in the log, I had one cylinder cool down. It was a miss I could only hear too, everyone at the track told me I didn't

So being time limited i swapped plug, coil and swapped two egt probes. The cooling trend went away on the next pass

Problem came back on another cylinder about 4 passes later, this time swapped coil and egt probes. Problem went away

So my super sweet eBay deal on gm truck coils might have 300,000 miles and don't like that dwell and boost combo!

What I'm saying is logging egt sure is a nice tool in the datalog
 
cwdodson88 said:
If I'm going this far, why mess around, just do it well once and go drive the piece. In order to do this, I need to upgrade to ms2. So, based on that, I must decide which limiting factors that I can remove.
Click to expand...

I'm honestly baffled why you pick-and-choose what information you read and regurgitate it in a fashion that's not presented from people giving you helpful advice on the subject, but that's not really my issue.

Yes, what we're saying is paying the cost up front gives long term benefits. Yeah, it's cool to do it now with something cheaper, but when we find the cheaper options has far more limitations than usefulness we always end up going back to the instrument that costs more up front, but does what we want it to do. I just learned this lesson by tossing out $100 worth of Chinese pressure transducers and spending six times that for instruments that will work as intended.

The best thing to do is save your pennies to add CAN bus abilities to your setup by upgrading to MS2. BUT, since that seems to be an issue, there's a far cheaper option to suit your short term goal, but it takes a little more work on your part.

In fact, DIYAutotune has done all of the hard work for you:
https://www.diyautotune.com/product/gpio-application-kit-egt-input/

Get yourself a small proto board and assemble the parts just like the schematic describes in the GPIO manual:
http://msgpio.com/manuals/egt.htm

Put that small proto board in a box, feed it 12V, ground, your thermocouple, and it spits out a 0-5V signal that can be integrated into an AD input on your ECU.

This will allow you to integrate a single EGT measurement directly into your ECU and datalogs for less than $50.
 
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As an observation. The video wasn't super clear; but, it looks like the hole in the header is on the side of the header tube? If so, that may or may not present some problems in terms of installing a probe.

The first potential problem is that the ALCOR application data that I have seen (www.alcorinc.com - which is for piston engine aircraft) suggests installing the probe a minimum of 2" from the header flange for NA engines. Farther for engines that are FA. They don't give details on why. Judging from your video, I don't think you are going to make that minimum distance. The photos of automotive applications that I have seen look like the bungs tend to be fitted around 3" - 4" out from the flange.

The second potential problem is space. The better quality probes (that withstand cooking temperatures) seem to use mineral insulation within the probe itself and up to the transition to the connecting cable. The application data recommends that the transition portion not be subjected to tight radius bends. Some of the EGT probes do come with a rigid 90 degree bend in the transition. However, those transitions look like a 2" or so radius. With a little searching, you may or may not be able to find a probe with a tighter radius bend. However, by the time you get a bung fitted on that hole, I suspect that you might have some space issues in terms of fitting the probe into that location on the side of the pipe.

This isn't an EGT issue; but, I would be concerned about the integrity of the exhaust header. I am assuming your reference to blowing a hole in the header meant that you didn't intentionally create the hole. If that is the case, I am thinking that you might want to have a really close look at that header pipe (and the others) before trying to fit a bung onto the pipe.

Some stuff to consider.
 
If I'm not mistaken, that's a '75 cast iron exhaust manifold that was equipped with air injection. The hole in his "header" is actually a blown out plug.

75B20ExhausetManifold.jpg
 
142 guy said:
As an observation. The video wasn't super clear; but, it looks like the hole in the header is on the side of the header tube? If so, that may or may not present some problems in terms of installing a probe.

The first potential problem is that the ALCOR application data that I have seen (www.alcorinc.com - which is for piston engine aircraft) suggests installing the probe a minimum of 2" from the header flange for NA engines. Farther for engines that are FA. They don't give details on why. Judging from your video, I don't think you are going to make that minimum distance. The photos of automotive applications that I have seen look like the bungs tend to be fitted around 3" - 4" out from the flange.

The second potential problem is space. The better quality probes (that withstand cooking temperatures) seem to use mineral insulation within the probe itself and up to the transition to the connecting cable. The application data recommends that the transition portion not be subjected to tight radius bends. Some of the EGT probes do come with a rigid 90 degree bend in the transition. However, those transitions look like a 2" or so radius. With a little searching, you may or may not be able to find a probe with a tighter radius bend. However, by the time you get a bung fitted on that hole, I suspect that you might have some space issues in terms of fitting the probe into that location on the side of the pipe.

This isn't an EGT issue; but, I would be concerned about the integrity of the exhaust header. I am assuming your reference to blowing a hole in the header meant that you didn't intentionally create the hole. If that is the case, I am thinking that you might want to have a really close look at that header pipe (and the others) before trying to fit a bung onto the pipe.

Some stuff to consider.
Click to expand...

Thanks.

The hole is TDC of the each tube. Some of the emission year start manifolds had been cast with a knock out for for EGR ports. The casting was such that it would take some force to remove them *edit* they actually may be tapped and blew from the threads of either the manifold or plugs being rusted out, and you have a little more than 1/4" of cast iron to tap for the bungs.

These are about 1/2" from the flange. I have found some EGT probes that are "ok" at this close of distance, but longevity is a concern.

Space is at a premium in my engine bay, and from what I've found from the drawings of possible probes, and my bent coat hanger mock up, is that I can get either a 90* or straight probe that will fit, the 90*'s offer a lot more cleanliness to the install.

I did hit my rev limiter, so there may have been one or 2 pops from the spark cut, but I had run nearly all summer and fall banging the flat shift limiter (same spark cut) without issue. I guess that a combination of cold ambient temps, and the violent effect of the spark cut lead to the blow out.
 
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hiperfauto said:
If I'm not mistaken, that's a '75 cast iron exhaust manifold that was equipped with air injection. The hole in his "header" is actually a blown out plug.
Click to expand...

Ian, mine looks almost identical, except for runner 1 and 4... Runner 1 is positioned closer to the head than yours, and runner 4 is a mirror image. They are spaced form the flange the same length as runners 2 and 3 as well.
 
hiperfauto said:
If I'm not mistaken, that's a '75 cast iron exhaust manifold that was equipped with air injection. The hole in his "header" is actually a blown out plug.
Click to expand...

Interesting. I don't think air injection ever showed up on B20s north of 49. Shouldn't be a surprise because Volvo was selling non catalyst equipped 240s until 1979 or later in Canada.

Looks ready made for the insertion of some EGT probes.
 
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