I thought it was 22-23 down to 16? Then screenshots of 25-27?

I think you're just having an issue with #s. 15-16 average is normal. Enjoy your truck/exhaust and don't worry about it.

 

If you look in the "Cam phasers post tune" thread on post #14. The info that he posted shows on page 22 that Ford says "Common modifications include the removal of catalysts, mufflers and resonators. In turbocharged applications modifications to the exhaust system can reduce backpressure and may result in over-speeding the turbo(s)."

 

Another post in a forum means nothing. That's simiply not how things work. The less backpressure present in the system, the more efficient the system, mechanically speaking. Whether the control system can handle that is another story.

OP is definitely driving differently or has something mechanically wrong. That MBRP didn't change anything performance wise and in identical conditions will perform identically

 

So I guess you didn't go there and read the info that is given to Ford techs?

 

I read the whole thing and that snippet you shared is not how engines or performance or they physics those entail works, plain and simple.

That PDF is barely a PowerPoint that anybody can make, I have to sit through em all the time and they're constantly full of errors

 

I really have no dog in the fight as I have a 5.0. But a turbo runs off of exhaust gases and the aftermarket exhaust allows the gases to exit faster. Then it stands to reason that the turbo would then be able to spin faster. NO?

 

I didn't say that it wouldn't spin faster, I said it's more efficient and any problems that arise from it are from the control system not being up to par. It's not going to overspeed the turbo. But also, a catback isn't changing anything. An aftermarket straight through muffler flows just like the stock straight through muffler.