Hi Todd:
I hope you received my email reply to the discussion between you and Sheldon. But perhaps some pictures of where my thermocouple is placed might help.
I picked this spot because it was easy to get to with a drill and tap without having to remove my turbo and exhaust manifold. Even though I have a turbo gasket kit with me, the last time I had to take off the exhaust manifold and turbo to replace a broken manifold stud was a pain in the butt...so I did it this way.
I realize that if I placed the thermocouple further up the exhaust manifold, it will give me a more accurate reading as to what is going on in the cylinders...but this spot is not bad, easy to do, and is a lot better than putting in post turbo.
After you get the right tap, make sure nothing will hit the wastegate rod after everything is put back together. Just remove the heat shield, drill, and then measure how deep you want the thermocouple to go into the elbow. You don't need to stick the whole thing in, and Sheldon measured several times trying to get the right depth. After you decide this, mark the depth on the threaded portion of the theormocouple bung and slowly work your tap until you can tighly screw the bung just deep enough to hit your mark. Make sure it's tight...and you're done!
For my turbo boost gauge, the guys at Piers Diesel gave me a plastic T so I could tap off of my wategate tube. Works well.
Many thanks to Sheldon and Greg B for lending me a hand. And yes, drilling and tapping into the turbo exhaust elbow is a little bit scary. I measure several times before drilling that first pilot hole, that's for sure.
HTH.
So if you can get a 90' drill use it. If not, its probably not a huge deal.
