Strongly recommend you tap the thermocouple BEFORE the turbo to get the most accurate readings. The turbo extracts heat and the temp differential pre-and post turbo will vary depending on the engine loading situation.
The exhaust runners are separate - there are actually two of them (carrying 1/2/3 and 4/5/6) separated by a casting. So don't tap in the middle - you need to offset the hole and get in the center of the runner to miss the center casting.
The exhaust runners are separate - there are actually two of them (carrying 1/2/3 and 4/5/6) separated by a casting. So don't tap in the middle - you need to offset the hole and get in the center of the runner to miss the center casting.