Long reply...
Nope, no boost module nor elbow. Just a K & N air filter.
I didn't set out on a mission to get this MPG..... but I was P---ed off big time over the rotten mileage I was getting, and the complete lack of power in the stock configuration. Stupid thing wouldn't pull itself out of a mud puddle... ... . it was that bad.
I decided that before I went back to the Powerstroke (22 mpg, and pulled circles around this thing), I would first attempt to resolve my issues with the dealership. LESSON #1: If you want your engine looked at by professionals, TAKE IT TO CUMMINS. I went round n round n round over this..... hearing the same old crap about how this is how all Cummins powered rigs are. Well, I knew better. Finally got DC to ok this thing being dyno'd and they'd pay for it. WELL... ... . I ended up looking like the proverbial jackass... ..... as it dyno'd out to 201 HP--the RPMs escape me at the moment.
So, what to do? Was dumping the thing, when 18-11-99 came along. YAHOOOO. It wasn't the best thing since sliced bread, but it worked somewhat. MPG went way up, as did the pulling power. But still couldn't hold a candle to my 95 Powerstroke. Then, I spent lots of time on this site, and decided for stealth purposes the VA box would be the way to go: power and stealth. Wanted to keep my warranty. And for all those who take issue with stealth vs. warranty issues, well, I/WE paid big money for a vehicle that should do what it is advertised to do, which is to pull heavy objects appropriately--I define "appropriately" as meaning my measly 22' travel trailer should go up our grades here in Oregon at the speed limit, if not well above..... and not drain my fuel tank. My Powerstroke would do it..... the Cummins is the better engine, so what the hay?
Got a VA from Ted J (paid too much, but so what, we paid too much for the truck in the first place

) and I have never looked back (BACK=BACK AT THE POWERSTROKES TRYING TO CATCH ME GOING UP THEM THAR GRADES

) No, the VA is not the "big answer"... . from what I see lots of progress has been made, and there are other products yall have that probably work as well if not better.
Bottom line, is for me, this VA made the diff between me dumping the Ram and going back to the Powerstoke. Why did I sell the Phord? Hmmmm... . after they dropped the engine on the truck (no kiddin. . hoist broke), after they couldn't fix the oil leaks, and after the trans was going, I figured Dodge hadda be better, and I liked the quad cab/short bed combo, especially with the Cummins.
Sorry for the long posting.
Rogue