BHAF - HP vs. Efficiency once and for all

[JWareing]

Hey all - thought i would post this here because im not sure it fits neatly into a "generation" discussion, maybe it does - but i was thinking of it as a more general question:

I have done a lot of searching and reading threads here on the merits of adding a BHAF in to the system on CTD engines... but most of these discussions seems focused on "upping horsepower" or "getting that great turbo noise louder" neither of these am i against on principle.

But i am having a hard time findind a real answer to the question: all other things aside, does putting in a BHAF increase the efficiency/fuel economy of running my truck? and in what other ways does it affect it - both good and bad?

My 1996 2500 4x4 bought used this summer came to me with a home made "medium honkin air filter" basically a medium K&N cone clamped to a homemade PVC elbow routed into the turbo intake..... propped up where the stock filter box used to be with some home-made hardware....

After I did my first oil change - ( i dropped the filter to turbo elbow to get at the oil filter) I noted dust on the collar of the turbo - and said "Uhoh!"

worried about doing further damage before resolving my questions- i put the stock filter box back in and put a stock flat air filter back in. I cant say that i have noticed a big change in fuel economy, but i havent been driving the truck alot lately for a fair comparison....

but i do notice i dont hear the turbo spool up anymore, and it does seem to "hesitate" on acceleration, and that if im on the pedal, then let off- there is kind of a "cough" from under the hood that i didnt notice prior to making the change....... any connection? and - does more air flow only contribute to noise/acceleration- or does it make me more fuel effecient also- or none of the above?! lol im confused!

PS- the only other thing I wanted to note for you sharpies is that the guy i bought the truck from had removed the "resonator" from the exhaust.... what effect if any does this have on things?

Thanks again for entertaining my long post and questions, and I look forward to any insight you guys can offer -

Sincerely- an enthusiastic but still green CTD newbie-

Jim