all -- I need to correct a previous statement I made and present the pre-versus-post issue more clearly. <br><br>before, I suggested that the 300 degree pre-versus-post difference was applicable up to 370 HP. The issue is not HP, as I was rightly corrected. <br><br>The issue at hand is temperature differential as a function of air flow in the turbo. the 300 degree differential only applies to boost pressures of 28 lbs and below and for the HX and HY 35 turbos -- this is because the higher the air flow across the turbo, the greater the temp differential will be. when you boost higher than stock, you fall outside of the operating parameters that cummins has established, and the 300 degree difference may not apply anymore. ergo, post-turbo readings are not accurate for protecting your pistons. great for shutdown, but not for pistons.<br><br>I'd be interested to hear from guys that have installed both pre and post thermocouples, and run high boost pressures. The point is that, especially when you exceed the efficiency map of the turbo all bets are off, with regards to the 300 degree difference.<br><br>so if you disable the factory wastegate, you better be measuring pre-turbo. you don't want your pistons to get too big

 

I read another post that concurs with what you stated.<br>The individual was getting 1000 degree post turbo readings using about 32-35 lbs of boost and 1500 pre-turbo. Looks like post turbo readings may be risky if one is pushing high boost numbers.<br><br>Jerry