It is my first turbo car, can you elaborate on this?

So a turbo has a bit of lag, both before you get going and after you let off. For example if you want to go 50mph, accelerate to 60 and let the car coast back to 50.
The factory maps are weird in that they don't add any WGDC until 40%tps (probably to hit their quoted MPG). I suggest you either give it more thottle to hit your speed in a lower gear, and then shift up to cruise, or short shift at 3k the whole way.

Relative to a V8 which you can give a slow steady throttle and the car keeps moving, you need to give a boosted car some momentum (which is what makes them so fun). Also, since it's new, to break the engine in healthy, do some accelaring to like 5000 rpm at 50-60 throttle and let off (this will create a vacuum and help the rings fully seal around the piston). It may sound weird, but this engine BEGS to be driven hard, babying it is not good for long term health

I'm aware of turbo lag etc, however terms like WGDC...not a clue lol.

So WGDC is Waste Gate Duty Cycle, it's a way of controlling the amount of boost. If there is none, you aren't building enough boost, which makes the engine all loud and clangy because it has increased the timing to consume the additonal air.....that isn't there.

The valve in the muffler is not *that* big of a difference.

Here is a youtube vid of my X totally stock on the dyno. You can clearly hear the tone change when it opens, but you can tell it's not that loud

You got PM!

I'm glad that am not the only one. I definitely will be this getting it check out. Post up when you get your new exhaust and tell us if there was a difference.

Weird. If your balance shaft gets out of time somehow, it will get suddenly real loud at 4k+ rpm. If I'm not mistaken, I don't think it is possible to slip though because yours are gear driven unlike the evo 8-9 which are belt driven.

Nice vid, shows clearly how the valve works. As for OP's issue, I must second the exhaust, most likely one of the balljoint connectors. At a certain pressure they could open up and might be causing this, if not tightened.

Take it to the dealer asap.

Never experienced what you described on my 2012 X MR. Can you hear your engine noise clearly over this 'droning' noise? If not, that's definitely not normal.

4B11 does not have balance shafts.

You confuse me. The ecu has boost sensors as well as the MAF to know exactly how much air is entering the cylinders at all times. Actually it uses further information to calculate exactly how much oxygen is entering the engine. I don't think slowly accelerating and not giving enough gas to fully spool the turbo is going to confuse the ecu. So why would it increase timing? just on a whim?

Look at a timing map and imagine load staying relatively flat while rpm rises. What happens??

I have a 2011 evo x with stock exhaust and bought it brand new. I actually did a boost leak and checked exhausts for leaks and there were none. This car is ridiculously loud after 4k RPM. It sound more like its coming from the engine rather than the exhaust. I had my 03 evo for about 7 years and the noise was much more uniform throughout the rev range.