Hp tuning

I'd agree, that's what I was getting at an additional 200° over the difference of a 200-250 on a single charger. Here is a 550 C-15 performance data I found I had on older computer.
Only ACERT I had saved was the 625 HP one and it had the better flowing/less restrictive high pressure turbo on the exhaust side.
It's in 300-400° swing range, but I believe the 550 setups was bigger temp swing.

 

Here's a 475 BXS.
550 MXS

 

Going off the numbers I see there I’m going to say that stupid little 2” pyrometer head in my ‘05 is probably sideways by 200* or so. Next to impossible to see, I guess it might as well be wrong. Thinking about conditions when it would usually read 600* or so it could well have been 800* easy enough. I’ll have a look into that when it gets back.