EGT

[03slvrstone]

What is the most reliable/accurate location to mount the probe for a EGT gauge? I have heard mixed answers from: mount in manifold, closest to turbo in DP and several others. Your input is greatly appreciated TIA

[SnowGti]

What is the most reliable/accurate location to mount the probe for a EGT gauge? I have heard mixed answers from: mount in manifold, closest to turbo in DP and several others. Your input is greatly appreciated TIA

You're going to get some mixed responses here:

1) Manifold Runner Closest to Cylinder #4
2) Manifold Collector
3) Downpipe immediately after the turbine discharge

Problems with 1,2 when using the stock exhaust manifold is that it's prone to cracking, and there is the possibility of  melting your EGT probe and sending the meltal bits into the turbine.  Installation is also far more involved and timing consuming.  The benfit is that you get the real EGT reading which is far more meaninful than the reading taken in the downpipe.

Option 3 is very very easy to install, and there is no chance of damaging the manifold or turbine, BUT the EGT readings taken in the downpipe just at the turbine discharge will not be very accurate and the EGT probe will likely read about 200 degrees cooler in this location.

Choose your whichever you feel most comfortable with.

[kilmer420]

I would suggest on cyl 1 not 4
but what he says makes sense

[03slvrstone]

so I should be safe installing it into the lower manifold in the picture on the runner furthest to the right.


picture from elitedubs


I would assume that the safest install method is to remove the manifold and then drill it? I have read and have found alot of answers saying yes and no about this...

[SnowGti]

I would suggest on cyl 1 not 4
but what he says makes sense

On my engine cylinder #1 has the highest knock voltage / timing pull.  ( However I run a TT intake manifold )

On the standard 1.8T Cylinder #4 has the highest knock/timing pull as it's at the end of the intake manifold and tends to run a little leaner.

That was my understanding?  Why is Cylinder #1 better on a stock intake manifold?  Just asking, not arguing.

[Spooled_AWP]

i really wouldnt advise putting it before the turbo....
alot of EGT probes are poorly made and like to break off from the extreme heat after an extended period of time....which could lead to turbo damage if the probe was placed before the turbo.

If you are looking for readings that are as close to accurate as possible...just get a wideband  :driving:

[03slvrstone]

:mswerd:  Thanks for the input

[HardIce2447]

put an EGT probe on each cylinder and see how they run across the board :evil3:

[AllofurVWRbelong2me]

put an EGT probe on each cylinder and see how they run across the board :evil3:

Thats evil.

....I LIKE it. :evil3:

[GraffixWB]

I know I don't know Too much about this , but I was told something that made a WHOLE lot of sence.  
Turbine Housing.      
 This is the place where ALL exhaust gasses collect. Your not looking for just one cylinder, but all of them. Don't worry about the probe breaking off, just buy a quality one. Buy a probe MADE for turbine engines.  Then your chances of having it break off as slim to none.  I've heard " you don't wanna destroy your expensive turbo, but wouldn't you want to destroy your turbo before you pop your motor?
Plus , your really not supposed to hit it hard before the engine is up to temp anyway...

I believe this is how Javad does it ?!?!?!  maybe  

[Spooled_AWP]

but like said....probe's like to break...often times VERY quickly...i had a probe break on me weeks after i installed it...im sure you definately wont want to replace a turbo often because of the placement of an EGT probe would you?

and if you are relying on an EGT gauge to determine whether you are going to pop a motor...then you should be driving the car...get a wideband so you know the REAL, MORE ACCURATE A/F mixture.

[GraffixWB]

I totally agree. I was just sayin that if you buy a HQ probe it should never break. One made for an airplane or a jet engine. Something that is meant to be run at high temps all the time. They have those suckers running in turbine engines for quite awhile.

What kind of probe were you using so I know which one not to buy?
 

[Spooled_AWP]

the gauge that comes with a probe is calibrate for THAT probe...if you switch out the probe to a different kind of probe then the calibration may be off causing the readings that come through on the gauge to be off.

i was using a VDO probe...and then didnt have much luck with an omori probe

[GraffixWB]

Well THAT stinks, So if A  probe goes bad then you gotta get a new gauge too?!?!   that's F'ed up..

[Spooled_AWP]

well no...if a probe goes bad on say a VDO gauge...you should probably get another VDO probe(even though we all know they are shit)...same goes for all the other ones out there for the most part

[enginerd]

VDO gauges with the big fat sensor are garbage. They respond slowly and can be off by 50+ degrees C.

You can find many different kinds of gauges that use a K-type thermocouple. I just did an install for a buddy using a k-type probe and an autometer  carbon series EGT gauge. When shopping for a gauge look and see that it says K-type probe.

Then Go here and get a high temp K-type thermocouple. Dont get the autometer/vdo/whatever probes they are cheap fat probes.

http://www.omega.com/ppt/pptsc.asp?ref=KMTXL_NMTXL

A 1.5 mm/ (1/16") probe will respond quickly and has a low likely hood of cracking off so long as you only stick it out into the gas stream about 1/8-3/16" of an inch. If you stick it out 1" it will surely vibrate itself to death. If your still scared get a 1/8" one. It wont respond as fast, but it will be twice as strong.

To install the probe, I use a stainless steel 1/16" NPT x 1/16" Compression fitting. I use a 1/16 drill bit to drill through the fitting (these fittings are for tubing and have a stop for the tubing) and insert the thermocouple in the compression fitting end,  and let it stick out the NPT end just 1/8 - 3/16" of an inch. Then tighten the nut and crimp the ferrule onto the probe. Back off the nut and you now have a removable gas tight probe.

Drill and tap into the exhaust manifold or turbine housing. Thread in the NPT fitting tight with anti seize (stainless is a bitch). Then install the Thermocouple and your set. Hook up to K-type probe and your done.

I get a fast response and accurate probe, and no worries about it flying off into the turbine. If you notice the gauge stops working get it out asap, and put in a new one. Gauges will fail electrically before they fly off. most people keep on driving fo rmonths with a bad gauge and then are pissed when if fly's off into the turbo.

If your really into EGT's you can get a digital thermocouple meter from omega. Digital readout responds faster, you can set alarms, and even get some with programmable loggable outputs. My egt's drop hundreds of degrees in half a second and i see them. i even see blips when the car missfires. Can even hook it up to other probes and switch between EGT, AIT temp, CAI temp, pre IC temp.......

Here's my setup

[GraffixWB]

UGH!!!  so what' the ANSWER!?!>!#Q@$%@#*(

So, does a good EGT probe hold or not?  I'll Start a pole here sooner or lata

PEACE :bowrofl:  

[enginerd]

A good probe that is properly installed will hold together no problem.