I was talking to my mechanic today about EGT location and he thinks it is a waste to put the probe pre turbo. He always puts his post turbo. His thinking is it gives you a collective reading of the whole motor that way. Just curious what the reasoning is for pre turbo as that is the way I installed it on my X.

Thanks

 

The concern is the temps going into the turbo.. Thus the pre-turbo thermo

 

Actually, the concern is temps into the motor.
My egt's are monitored both pre and post turbo (not downpipe but intake).
I tapped the intake Y to keep an eye on the real temp my engine is breathing.

For the record, after the intercooler, average temps are - 200 degrees.

As for mounting the probe in the downpipe... worthless.

 

Exactly. The turbo draws a lot of heat out of the exhaust gasses, so post-turbo egt readings can vary wildly depending on load, air temps, boost, etc. The one thing you are trying to protect first is the pistons. Those will melt long before any damage to the turbo could possibly happen. Having a probe in only one manifold is fine. Nothing wrong with monitoring one bank. If there are problems on the other side, you'll quickly know even without looking at a gauge.

 

Sorry, that's what I meant to say. Came out wrong. There was a pyrometer on my truck when I bought it and the probe is on the downpipe. I'll be tapping my intake when the new 4" downpipe goes in this weekend.

 

Iam a little confused. Where is the best place to tap in for the EGT probe
Thanks
Nick

 

As you can see in the pic, my EGT probe screws into a threaded bung that's welded to the drivers side up-pipe, near where the up-pipe attaches to the exhaust manifold. Some drill and tap the cast iron manifold, just forward of my location.

A primary reason for putting the EGT probe in either of these two locations vs the DP is response time. If you put your foot in it to start towing a steep grade, your post turbo EGT reading will have enough time lag that you might burn a piston before you realize it. The up-pipe or manifold location responds very quickly to increases in fuel.

 

There are some mis-use of terms here as well. EGTs have nothing to do with the intake. That's the AIT or MAT measurement (Air Intake Temp & Manifold Air Temp respectively). There are two choices for EGT -- post turbo and pre-turbo. Some after-market down-pipes come with a bung installed for an EGT sensor which is very tempting to use because it's so much easier. I wouldn't do that. It's not that big of deal to drill & tap the manifold or up-pipe, and keeping more accurate tabs on those temps at that point will save your pistons like already mentioned. People have been getting the misconception that EGTs are monitored because of the turbo, which as has already been mentioned is not the case. Aluminum pistions will melt in the combustion chamber way before any steel or alloy part of the turbo will further down the exhaust path, which was also mentioned already...

 

Thanks for the info guys. It makes since to me now, I just wanted to know the logic behind the location.

 

Thanks for clearing up all the terminology Joe.
So I've got an EGT probe mounted as an AIT...

Who'da thunkit.

 

Alrigth so post turbo is where I want to tap into,
Thanks
Nick

 

pre turbo, pre turbo, pre turbooooooo!!! not post turboooo!!

 

That's right, I only really used the egt probe in my intake Y because of removal of a NOS jet.
Figured, why not put a guage on it.

For an accurate reading of 'exhaust gas temperature' you need to tap an up-pipe or exhaust manifold. I tapped both uppies, the temps are about 100 degrees different, left to right bank, left bank always hotter.

Analyze that Gene!

 

I already did that analysis here...

Does EGT give a false sense of security?
https://www.ford-trucks.com/forums/590447-does-egt-give-a-false-sense-of-security.html

... and your observation is why I recommended in that thread to never exceed 1100 F when towing a grade. You need to provide a safety margin to account for variations in fueling from the individual injectors. Unless you've an EGT probe in the passenger bank, you'll never know for sure how hot its running.

 

So to REALLY know... you'd have to run eight different probes?

Imagine keeping up with eight EGT gauges!

CSIPSD could show where to mount 'em.