Optimum Position for EGT Probe On Manifold

[Gernster]

Have bought myself an EGT guage (& Boost) whilst my head is off.

Looking for the best place to drill & tap on a 1.6 GTD (SB/RA) exhaust manifold. I know I need to get close to the Turbo, but can you get too close??i.e should I be fitting right next to the turbo joint ot after the bend as it goes down to the downpipe?

[dillenger1]

Nope,that will give false readings .It will be cooler there by hundreds of degrees.You need it in the the combined stream in the exhaust manifold,preturbo.

[saurkraut]

Put 'er here:

[arb]

I put mine at the junction of the 3 & 4 runners. My first attempt resulted in a cracked manifold - so I used the drill press after I welded my crack. Here's my post on that - towards the bottom.

http://www.vwdiesel.net/phpBB/viewtopic.php?t=15633&postdays=0&postorder=asc&start=0

[saurkraut]

The standard transverse manifold can easily be drilled with an electric hand drill.

Cobalt bits go through it like a hot knife through butter.  Make sure to cool the bit with some oil, WD40 works great.

[Gernster]

thanks guys, good job I asked!

[Smokey Eddy]

I see arb used high temp sealant. Did anyone not use any sealant? just drill tap and thread it in?

[saurkraut]

The Spruce and VDO thermocouples (The spruce thermocouple is the fastest) have pipe thread adaptors.

Pipe thread is tapered.

No sealant required.

[Jet A]

dont forget your antisieze....

[Gernster]

dont think I'll ever have cause to remove it mate

[Jet A]

Dont think youll remove it huh?

Seems easier to put the antisieze on that it will be to get back on here and ask how to get it out without damaging it....

[79rabbit4dr]

What about on a non-turbo'd rig? should it still be on the manifold, or can it be down on the pipe within the first foot or so of the block? Just wondering because I don't have a welder to fix my manifold if it cracks when tapping it for the probe. Picture for reference?

[zukgod1]

Put it in the manifold.

I've never seen one crack due to drilling/ tapping.

The sender needs to be as close to the head as possible and in the combined exhaust stream.

[rabbitman]

The sender needs to be as close to the head as possible and in the combined exhaust stream.

Why do you say that? If your running 1000 Degrees F in one cylinder, measuring two cylinders simultaneously won't show 2000 degrees.
Or is the probe in more exhaust so that makes it more accurate?
Seems to me if you put it too far from the head just to get all four cylinders it would read cooler because of the extra distance from the head.

[zukgod1]

The sender needs to be as close to the head as possible and in the combined exhaust stream.

Why do you say that? If your running 1000 Degrees F in one cylinder, measuring two cylinders simultaneously won't show 2000 degrees.
Or is the probe in more exhaust so that makes it more accurate?
Seems to me if you put it too far from the head just to get all four cylinders it would read cooler because of the extra distance from the head.

Correct it wont read 2000 deg, if you only stick it in the stream of one or 2 ports you wont know what the others are doing. If you have 3 cyl running 600 and one running 1200deg it will show up on your EGT as a higher reading than the 600 deg thus the "Combined stream" application.

You are looking for a average here.
I said in the combined stream as close to the head as you can get so the average you are reading is more accurate, yes the farther from the head the colder it will read.