Hey guys I was just about to drill a hole for my pyrometer I just got but...
The instructions clearly say for turbo engines, to install the probe after the turbo? I have read on here before to install it before the turbo. I am running a second gen elbo after the turbo, and a second gen down pipe, and the elbo has a boss cast into it for a pyrometer. Does this mean cummins wants you to read the exhaust temp after the turbo?! If this is so, then from what I here most of us would be running cooler than we think, or what cummins thinks safe. So now I dont know wher to put the probe?
Please help.

 

Put it in the manifold. It's not accurate after the turbo, it changes a lot based on how much boost you are making.

 

I think Cummins is trying to cover their rear, by saying to put the thermocouple post turbo. So just in case the probe would break loose, you wouldn't have an expensive repair bill.

As long as you stay within the temp limits of the thermocouple, it should be just fine. No problems with mine. Still looks like new.

 

Most manufactures will tell you to put it after the turbo in case the tip of it breaks off. Being before the turbo would cause much damage to the turbo. After the turbo seems to be industry standerd for this reason.

However before the turbo is a bit more accurate and I have never heard of a pyrometer breaking off and going thru a turbo.

So its up to you. Personally mine is after because thats where the previous owner put it and I don't think its a big enough deal to to bother moveing it. If I was installing one myself I'd probably put it in the manifold but since you already have a bung in the down pipe for it I'd be tempted to put it there as well.

 

Put it in the manifold. Unless your hitting 1800 degrees and melting the tip off, it won't do any harm. Much more accurate and it's what you need to drive by.