Exhaust Gas Temperature Probe

[GregATL]

I am looking into putting an EGT sensor on my car. I plan on using a standard thermocouple(type J,K, etc) and using my multimeter for the readings as it has thermocouple capability.

My question is what is the max temperature I should use when spec'ing the thermocouple?

1600F, 2100F, more? I don't really know much about acceptable EGT's so I need some guidance here.

Thanks.

[turbodan]

I'm not certain, but I would think 1500C would be absolutely scorching. I can't imagine you would need any more range than that.

[Ken H.]

1500 deg Celsius = ~2700 deg F. Most pyrometers (EGT probes) and related gauges are set up for ~1600 deg F. as a max reading. The probe can be set up at the top of the exducer downpipe.

[GregATL]

Thanks for the info Ken. So you are saying the entrance of the downpipe is the best place to get the reading from? That's good to know.

[karl]

I think the most desirable location is in the exhast manifold pre turbo where you will get the highest temp/pressure readings. rule of thummb in oil burnrers is over 1200f sustained here can cause problems. A temp drop of 200f is what I have found across the turbinne.

[Ken H.]

I think the most desirable location is in the exhast manifold pre turbo where you will get the highest temp/pressure readings. rule of thummb in oil burnrers is over 1200f sustained here can cause problems. A temp drop of 200f is what I have found across the turbinne.

No question. Difficulty is getting a workable location pre-turbine on the M30 log manifold that accurately reflects the EGT. Using the post-exducer location will yield a lower temp, but knowing that, it's easy enough to establish what normal working temps ought to be.

[Maddog]

The EGT sensor should be placed in front of the hottest cylinder in the exhaust manifold. This isn't particular easy in a log manifold as has been stated. Heat loss in a turbine housing is not linear with temperature which is why is isn't a good idea to put the EGT sensor after the turbocharger.

If you are using a TCD manifold and want a general EGT reading, I would place the sensor right before the wastegate on top of the manfold. That is the best place I have found for it based on the casting thickness and best cylinder coverage. This won't cover all cylinders but should give you the best general reading without being affected from being too close to the edges of the manifold.