Author Topic: Product review: Aircraft Spruce EGT Thermocouple  (Read 27129 times)

August 01, 2006, 04:27:10 am

fspGTD

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Product review: Aircraft Spruce EGT Thermocouple
« on: August 01, 2006, 04:27:10 am »
Hey folks -

I wanted to take a few moments to make a strong recommendation for a specific pyrometer thermocouple probe I have just completed testing on.

Result: Can you imagine an EGT gauge reacting nearly as quickly as the boost gauge???  VERY QUICK REACTION!!!  That's what I am seeing with this probe... I highly recommend it.

It's a model sold at a dirt-cheap price by aircraft spruce:

part number 10-01478
Here is the link to their website with it:
http://www.aircraftspruce.com/catalog/inpages/micro8egt.php

Aircraft spruce is very pleasant to work with and can ship small orders no problem by parcel post.  I opted for the 1/8" NPT version... which is a little less material to drill and tap into the exhaust manifold and a little easier to position than 1/4" NPT.

This unit is fully shielded (not an exposed junction) but yet very thin barreled, and with a skinny tapered tip, making it in theory quite quick reacting, only slower than an exposed junction type.  The fully shielded should make it long lasting and reliable in a sooty diesel exhaust environment (unlike an exposed junction type probe I'd imagine.)

As for an installation location, here is where I opted to install my thermocouple this time around:


Although I have previously gone straight into the turbocharger's turbine housing, I wanted a location that was preturbine and balanced across all four cylinders, but also allow me to swap between two different turbos without swapping the thermocouple or buying two of them.

I'd like to give fatmobile some credit for inspiring this location (via his excellent post with pics here), although I did change the location a little bit to avoid the downpipe support bracket bolt (to make it a little easier to maintain.)

After the drilling and tapping...


Can't forget the anti-seize (this fitting is very high quality stainless by the way.)  Copper-based is a good idea for any fasteners that touch the turbine housing or exhaust manifold.


And the final installed position of the probe.  I wanted it preturbine, and so all four cylinders supplied heat:

The hole had to be angled to be well centered in the exhaust port and also clear downpipe support bracket underneath:


Oh yeah - another thing I wanted to share: I have had problems in the past with my EGT gauge going out because of the thermocouple electrical connections in the passenger compartment becoming corroded.  My solution this time was replacing the connectors with some weatherpak connectors.


These very slick little guys are quick-disconnectable and completely shield the conductors from the outside atmosphere/moisture.


Jake Russell
'81 VW Rabbit GTD Autocrosser 1.6lTD, SCCA FSP Class
Dieselicious Turbocharger Upgrade/Rebuild Kits

Reply #1August 01, 2006, 10:18:06 am

larry104

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #1 on: August 01, 2006, 10:18:06 am »
Just curious, have you measured the temperature drop between the manifold (pre-turbine) and downpipe at the turbine exit? Just wondering if the two temperatures are consistently different, or if the delta varies significantly. Also, will that thermocouple work with a VDO pyrometer?

Reply #2August 01, 2006, 12:55:18 pm

malone

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #2 on: August 01, 2006, 12:55:18 pm »
Thanks for the info Jake. I will need to get a new EGT thermocouple for my next diesel build so this one will be considered. $24 USD!

I'm also curious as to know what pyrometer gauge you're using.
http://www.tunezilla.com
93 Eurovan AHU TDI
96 Golf 1.9L ASV TDI - I bought it back!
97 Golf Variant Syncro 1.9L 1Z TDI - sold and missed
11 Golf 2.0L CJAA TDI DSG - Stage 4
14 Golf Wagon 2.0L CJAA TDI DSG - Sold
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Reply #3August 01, 2006, 05:37:50 pm

Dr. Diesel

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #3 on: August 01, 2006, 05:37:50 pm »
Jake, will that TC work with any guage, or is there a specific gauge required?
I repair, maintain and modify VW's and BMW's.
Good work done at affordable rates. Welding and fabricating, too.
Performance Diesel Injection's Super Pump: gotta have one!

Reply #4August 01, 2006, 08:20:25 pm

hillfolk'r

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #4 on: August 01, 2006, 08:20:25 pm »
hey thats where i put mine,sweet

 mine came with a chart that told ya the different voltage outputs at different temps

im not sure if its guage specific,but i think ya may wanna keep the manufacturers the same
yours is a little newer style than mine

um,why not get 2 probes,"spruce" offers guages that have 2 egt guages in one guage
put one per+post turbo
Throttle cables ftw

Reply #5August 03, 2006, 01:54:26 am

starrd

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Re: Product review: Aircraft Spruce EGT Thermocouple
« Reply #5 on: August 03, 2006, 01:54:26 am »
Quote from: fspGTD
Hey folks -

Oh yeah - another thing I wanted to share: I have had problems in the past with my EGT gauge going out because of the thermocouple electrical connections in the passenger compartment becoming corroded.  My solution this time was replacing the connectors with some weatherpak connectors.


These very slick little guys are quick-disconnectable and completely shield the conductors from the outside atmosphere/moisture.


Jake, I just read this and thought I had read that introducing a connection point other than at the cold junction will cause problems.

I did a search and found the following:

"Connection problems. Many measurement errors are caused by unintentional thermocouple junctions. Remember that any junction of two different metals will cause a junction. If you need to increase the length of the leads from your thermocouple, you must use the correct type of thermocouple extension wire (eg type K for type K thermocouples). Using any other type of wire will introduce a thermocouple junction. Any connectors used must be made of the correct thermocouple material and correct polarity must be observed. "

In other words the metal in the plug should be of the correct material for a proper reading.

Don
Black 1996 Passat TDI Malone tune, K03/04 Hybrid, Keyless, VR6 Clutch & PP357's
White 1993 Passat TD - GTD nozzles, Keyless - Giles pump, K14, Intercooler, 228mm VR6 clutch & PP, CTN Trans etc
Red 1990 Corrado - custom chip by

Reply #6August 06, 2006, 12:51:59 am

935racer

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #6 on: August 06, 2006, 12:51:59 am »
Quote from: libbybapa
It is my understanding that any gauge of a given type (type K, type J, type R/S, etc) will work with any thermocouple of the same type.  The manufacturer doesn't matter, the type does.

Andrew


I have swapped gauges meant for the k thermocouples before and they appear to read the same.

One thing I would like to see is how fast this thermocouple responds compared to my autometere and isspro gauges I usually install.

Reply #7August 07, 2006, 10:28:01 pm

fspGTD

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #7 on: August 07, 2006, 10:28:01 pm »
I made sure the connectors I used (the standard weatherpak ones by the way) are the same material as the original standard "lug" type pyrometer connectors... tin plated metal of some type (I'm gonna say going from memory I believe it's tin plated copper, but could be remembering that wrong.)  I made sure to crimp them on instead of soldering them, just like the original connectors. :)  As I understand having solder in the thermocouple signal can mess up the reading accuracy.

I should take a video of the pyro gauge reacting...  I'm serious that it's almost as fast as the boost gauge!  What's really amazing is how fast it cools down now.  The motor is cooling down a lot quicker than I thought.

With my old setup, I could determine how long to idle the motor (before shutting it down, to cool down the turbo) by watching the EGT gauge and just waiting until it dropped below 200 deg. F.  With my current EGT setup if I did that, it would take barely any time at all before the gauge reads that cool!  I like it.

I am using it with a VDO "cockpit" series non-powered pyrometer, but it should work with any other automotive pyrometer ("K" type.)
Jake Russell
'81 VW Rabbit GTD Autocrosser 1.6lTD, SCCA FSP Class
Dieselicious Turbocharger Upgrade/Rebuild Kits

Reply #8August 08, 2006, 12:01:23 am

QuickTD

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #8 on: August 08, 2006, 12:01:23 am »
Quote
The motor is cooling down a lot quicker than I thought.  


My EGT guage reading drops fast after a hard run too, but if you go back 5 minutes after shut down it'll be back up at 500º. Seems the actual gas temperature drops quite quickly, the manifold and turbo temperature does not...

Reply #9August 08, 2006, 01:24:32 am

hillfolk'r

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #9 on: August 08, 2006, 01:24:32 am »
yea on mine,it drops rightoff whenits unloaded,i think its like 10x more responsive pre turbo,as opposed to post turbo
i have had this thermocouple in both places
when im cruisin,its like 600-700 f
and if i nail it it leaps right up to 11-1200 like an electrical guage almost,ona major burn it down run,ive seen 14-1500 on the tdi(preturbo)
yea when i pull in the driveway,it goes to 300 pretty quick,then i let it run till it says like 200-250,that takes it a min or 2
overall view
guages from l to r on top of dash
 the little 3 pod setup on extreme left  has volts,water temp,oilpsi
tach  is in middle
egt,boost,oil temp on right on that old gti guage face plate painted black

egt,boost,oil temp,close up

air cleaner restriction,boost pressure,fuelpressure

im lying here a little,the aircleaner+boost guage arent hooked up,they just fill the holes
the "fuel pressure" guage is actually a summit brand digital oil pressure guage,reads from 0-99 psi
guage was 30 bucks,and sender was 12 i think
i drilled and tapped one of the fuel filter banjos for 1/8 npt for the sender for the psi guage
Throttle cables ftw

Reply #10December 09, 2006, 08:18:08 pm

klr650@

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #10 on: December 09, 2006, 08:18:08 pm »
Ok here's a dump question. I order the 1/8 npt egt probe (10-01478) from air spruce. I have the manifold off the block and I would like to drill and tap the manifold while its off (just like in the pics).

What size hole and tap do I need to make it? I don't have the probe yet so I can't go off of it.

Thanks,
Dave
1993 Suzuki Sidekick w/ 1.9TD

Reply #11December 09, 2006, 10:24:10 pm

klr650@

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #11 on: December 09, 2006, 10:24:10 pm »
That's what I thought, but I wanted to make sure before I go drilling holes.

Thanks
1993 Suzuki Sidekick w/ 1.9TD

Reply #12December 10, 2006, 05:11:29 am

Hillshy

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Aircraft Spruce EGT Thermocouple HAVE UK REP TOO!
« Reply #12 on: December 10, 2006, 05:11:29 am »
Hi Jake n all,

cheers to the link in ref to "Aircraft Spruce EGT Thermocouple" i went to their website to check EGT related stuff, i knew they are based your side of the pond, but they have a UK rep, so we too in the UK can benefit from their products without having to pay massive shipping costs.

 :!:
the link to the uk side of their business is www.airworlduk.com and he's friendly and easy to deal with.

as theres other uk poster here i waned to let them know also.

i managed to get a thermo extension cable for my EGT as mines a Brick, only cost £7.00 :o . well chuffed, been hunting high an low for the right cable. :lol:  :lol:

Thanks again,
hillshy
Hillshy T25 caravelle "Hilli" currently thrashing 1.6 td GTD engine
NOT SO FRIGGEN HILLSHY ANYMORE!
15psi of BOOST set my c'velle free

Reply #13December 10, 2006, 03:34:23 pm

Black Smokin' Diesel

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Re: Aircraft Spruce EGT Thermocouple HAVE UK REP TOO!
« Reply #13 on: December 10, 2006, 03:34:23 pm »
Quote from: Hillshy
i managed to get a thermo extension cable for my EGT as mines a Brick, only cost £7.00 :o . well chuffed, been hunting high an low for the right cable. :lol:  :lol:

Thanks again,
hillshy


Do you know if it's a UK only item and can it be bought on their american website? Do you have a part number?

Thanks.
91 Passat syncro 1.8T swapped.

Reply #14December 26, 2006, 07:30:01 am

carrizog60

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Product review: Aircraft Spruce EGT Thermocouple
« Reply #14 on: December 26, 2006, 07:30:01 am »
i am a bit rookie...
can someone please give the the part numbers or links to what i need for a complete setup?
i dont like very much the gauges i saw on theyr site...can i buy other and link it to theyr probes?

thank you
vw golf gti G60--vw passat 1.9td gt2052v
yamaha vmax 1200- yamaha tdm 850
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