om 617 engines performance

here I am again,
I talk to someone at G-center NL, apart of saying that the turbo version of the OM617 works great in the G en that they will do the swap, and saying that the pump must be regulated at a "BOSCH" centrum, they take the pump from the engine and install it on a special pump test bench , I mentioned that the test bench maybe had calculated the normal flow of air that a standard OM617 generates , and use this as one parameter (among more) to regulate the pump, but when the engine is modified for more air intake, easier exhaust enz...., the test bench doesn't keep this in mind, so the BOSCH regulation would be a waiste of money.
concerning the injectors, they always use the standard Bosch parts, and never tried something else, while this part is a very important one in the amount of power the engine delivers, the injector is regulating the pressure, a spring holds the pump flow untill the pressure is high enough to overtake the spring power, at that moment injecting an amount of fuel, because of the shape of the hole in the injector and the build up pressure, this results in a cloud of fuel which mixes with the air, and form the explosive gasses, so its not hard to understand that the injector plays a major role in this chain, and therefore would surely be a candidate to improve, but like I learned from my experiences with gasoline engines, you can only improve properly the performance of an engine if you change the hole "circle" not just change only one thing, like if you put a k&n filter, your engine is taking more air in, this by itself would not lead to a notable difference in power, but by the increased air you can feed it more fuel, now if you alter the ignition to adequate ignite the bigger gas cloud, and if you alter the exhaust system to let the increased burned gasses out enz....enz.... than you can increase power, that's how it works, now gasoline engines do not have any secrets for my, but the diesel engine is slightly different while there are some things that are common there are also a lot of differences, I'm not a diesel expert that's why I need some help
so if someone has useful information please let my know, maybe some good sites on this issue on the internet, or someone who has experimented with diesel engines, what ever, let my know
happy holidays for all of you, and may 2004 be a year full of G fun, Oswald