Up pipe and exhaust manifold will register the same before turbo reading. It would be the down pipe that would require you to think in terms of after turbo readings. Before turbo 1250 is max temp and you do not want to stay there long. Considering varryances in gauges,carbon buildup on the probe, etc, it's best to play it safe and keep it below 1150. I'll tow heavy and pull a mountain at 1100 -1150 all teh way up no worries. After turbo it's considered max around 950