I noticed the difference right away with my ECU tune, when I let off the gas at higher RPMs there's a definite change, not quite a "backfire" but way different. All I have to do is downshift using the paddle and it's there. Do you guys with the add-on units notice that? JC. I realize I have a different car yes.

 

Naw, the modules only increase boost by fooling the ECU about MAF sensor, or the MAP sensor readings.
Pop and burble is a result of fuel and ignition timing, which units like JB+ don't change.
No difference on my 2013.
I have a Dinan arriving for the 2017, Ill let you know.

 

ECU tunes, for example Bytetronik modify what causes the pops so they are more frequent, or louder, or something.

Piggybacks will not affect the pops.

A catless downpipe REALLY makes the pops loud.

 

Might just be me, but mine seems to "pop and burble" more since I had my software updated.

 

Same - it's popping and burbling in normal and even occasionally in green mode.

 

I wonder if it's ASD doing it. I've disabled ASD on my '17 JCW and although people say it's only about Engine noise, I found the exhaust "highlights" are noticably absent, even on Sport mode. I used to hear them over the music and now I strain to hear them with the music off.

 

An update to this - I pulled my NM Power Module off last week to get some warranty work done, and on the drives to/from the dealer, there was more popping and louder popping without the power module than with it on.