m16' - i understand that's what the vendors say, 200° - 300°. but then they also say it could be as much as 500°. that doesn't seem like a large margin of error?
the point is that there are a tremendous amount of variables that alter accurate indication, way more than pre-turbo. the deviation is not constant (linear).
no need to patronize John - you, too, also know that the
'just add 100° and you'll be fine' advice that was given is not correct. i'd love to install a 2nd gauge to note variances. but to map the actual deviation you also need to record rpm, boost, and drive pressures in addition to both temperatures. however, i also don't want to that much trouble. so, for all intents and purposes, i'm wrong. and that's ok.
however, if you would still like to do it, i'd love to see your observations. exhaust manifold, near the turbo flange, at the collector, rear bank please.