'm with Jim on this one.  The easiest way to have EGT is by just putting one sensor in the pipe.  You could try to install two in the manifold, but I'm not sure you'd really get two independent readings. 

 

Hey Todd, didn't you do something like this with the turbo manifold? 

        In the turbo manifold there is a switching valve that is unnecessary in our applications, so while removing it there is a 1/4" hole to fill. So I tapped this hole to 1/8"NPT. Then I took a 1/4" tube X 1/8"NPT, 316 compression fitting (Parker) and drilled out the shoulder to allow a 1/4" tube to pass completely through. Threaded this into the manifold. Then I took a 2" piece of 1/4" tube and TIG welded the end to form a thermowell. Into this I inserted the K-type T/C that I made by twisting the ends of T/C wire together and TIG the ends.

         At the time I did this I wasn't aware of the difference between T/C wire and T/C extension wire. The T/C I installed downstream of the turbo, only saw temps in the 700F range and continues to work, while the T/C in the manifold saw temps in the 1400F range for a little while. When I recently removed it the end was completely gone, but the homemade thermowell still looks like new.

        I've spent the last day perusing through the Omega catalog and found that they sell compression fittings with the modified shoulder for exactly the same use as the ones I made. At work here we have a huge roll of K extension wire leftover from the old days before the switch to RTD's, but nothing else so I'm going to order a selection of goodies from Omega tonight. They actually have an amazing selection of T/C's and accessories for almost any application, so I'm confident that I can come up with an efficient terminal block design for the engine compartment.

        One question that I have regarding location involves my downstream EGT sensor. I was previously seeing temps in the 700F range. At first I was amazed that there would be this much temperature drop through the turbo and was impressed that the turbo could absorb that much heat energy from the exhaust. However my probe is located approx. 12" and 2, 90degree bends downstream from the turbo. Could it be that it is just cooling off that much? I find this very hard to accept as well. Located approx. 2" closer is my O2 sensor. Reading my EMU manual, I read a warning that O2 sensors will only work when heated to 800F or higher. This was connected to RWS's mixture monitor, which seemed to work but I did find it a little unstable, which could be due to insufficient heating (Tracy, any comments?)

S. Todd Bartrim
Turbo 13B
RX-9endurance
C-FSTB
http://www3.telus.net/haywire/RV-9/C-FSTB.htm

        "Imagination is more important than knowledge"
                                        -Albert Einstein