I just picked up an autometer pyrometer gauge and im looking for a thermocouple/probe and im not sure which one I should get. A google search turns up a bunch of links to forums that almost all say get the TRE probe. Do they even still sell them because all I saw on their site was transmission stuff.

Are all probes ment for automotive applications universal? Is one better than another? Which one do you guys recommend? Thanks

I don't know if TRE used a proprietary or custom EGT probe (also known as a thermocouple) but I'm going to go out on a limb here and say that I highly doubt it. I'm pretty sure it was stated before that TRE simply stocked K-Type "exposed junction" probes, which simply means that the 'wires' (for want of a better description) that measure the heat (or more accurately reference it) are exposed and not protected by any sheath. This leads to a very fast response time and is why many users report being able to see temperature variations whilst changing gear and simply revving on their driveway. As is always the case, you don't get something for nothing and the downside of the faster response time is a shorter service life. These type of probes do not withstand pressure or any type of corrosion well so you may find that probe placement or the type of fuel used (plus your tune) could affect service life. That said, plenty of people seem to see 15-20K service lives, which might not be as good as the life span of a good quality O2 sensor but it's not that bad either.

If you really want the TRE probe, maybe try sending Harry (number3) a nice PM. He is good friends with Jon and seems to be able to get a hold of him when others can't. I'm sure he can find out if TRE still sells these and even if they don't, I can't see why Jon wouldn't want to disclose which manufacturer they used. Post up if you find out, it would be good information for the board to know even if today the EGT is a less widely used tuning tool than the AFR Gauge. I'd almost put money on it being a big brand name like Bosch.

If you have no joy with the TRE probe then start shopping around on the net for exposed junction K-type EGT probes.

Paul.

Edit: No, not all thermocouples are universal in application or intended for automotive use. The designation "K-Type" indicates that the thermocouple has a specific temperature range in which it can be used. These links have some basic but quite useful information.

Introduction to Thermocouples

How Thermocouples Work

Great information Paul. Thanks. Ill be sure to get ahold of number3 and ask him.

Im not dead set on getting the probe from TRE bit I figured of it worked so well for everyone that used it I would start my search there. So what im looking for is a k-type thermocouple? Is there anything wrong with the one that autometer sells fpr their gauges? If I can't find the one TRE used what would be a good one? I realize that using an EGT gauge isn't used as often as a wide band, which I already have, but it was a good deal and complements the other two phantom gauges I have.

Have you got a link to that probe? What does it say about it? And I'm not knocking you installing the gauge. I bought one too for exactly the same reasons LOL.

web page

This is autometers street probe. I'm not set on it but I figured the people who made the gauge would be a good start.

I don't think there would be anything wrong with that probe but it's a closed tip probe so expect slower response times coupled with a longer service life. Another thing I read after looking at your (and Chris') reply in my own EGT thread (thanks by the way!) is that exposed tip probes aren't recommended for pre- turbo installation because if the tip breaks off it will destroy the turbo. I think another selling point of the TRE probes was the size of the tip and the suggestion that if it did break off it wouldn't take the turbo with it. /ubbthreads/images/graemlins/dunno.gif

Personally, I'll be using the EGT as a warning device, rather than a tuning device, although realistically, I am sure if temperature readings are consistent, you can use it to tune by looking at fluctuations in temperature rather than the actual temps themselves. I see it in the same light as a dyno in that respect. The figures are meaningless but the differences in figures allow you to tune very effectively. In any event, I myself would want a fast responding probe (think milliseconds rather than seconds). If the TRE one is no longer available, I personally would look at the Stinger series from Exhaust Gas Technologies. As I said before, I suspect if you ever get an answer from Jon you will find out his sensor was produced by someone like these guys.

Great information /ubbthreads/images/graemlins/applause.gif, I will be sure to put it to good use. /ubbthreads/images/graemlins/grin.gif
Thanks for all the help.