Thank you for the reply.
With regard to the following statement: "On its own an intercooler doesn't make any power, it just allows more air in to the engine." I agree that the intercooler allows more air into the engine, because the cooled air is denser, more compressed, than the hot air exiting the turbo. To my way of thinking, delivering more oxygen to the engine would increase combustion efficiency and result in higher horsepower. Without a turbo though, an intercooler would not be worth the cost of installation.
I would be interested to know what amount of horsepower, if any, is derived strictly from direct injection vs indirect injection. I'm unable to find this information on the web and I'm not versed in the volumetric efficiency of the two different methods of getting fuel into the combustion chamber. Still, "direct" always sounds better than "indirect."
I have a low mileage (61k) 1z engine on a stand equipped for installation into my 1986 Westfalia. I also have a very nice LR300tdi pump with machined hub, alh shaved sprocket, and enlarged ahu/1z bracket. I've located an aaz, also low mileage, that's ready to go as is for $1950 shipped. I'm trying to decide which way to go, hence the discussion on horsepower of the ahu/1z vis a vis the aaz.
I realize this is my decision, but I am wrestling with it because I've no experience with turbo charged diesels, only the na models.
foxfour