Turbo's-"Wicked"?? Yep, Wicked good"!!!
The question of 200 hp didn't ask "easiest" it asked the most cost effective.
Same thing but different---
"Everything in the engine is designed to support that level of hp plus an unknown but substantial over engineering margin"===This is done for every quality engine build.
"Without reworking rods, rod bolts, engine cyl studs, main bearings, rod bearings, flywheel, flywheel mounting, balancing, pistons"=Again, accomplished on any quality engine build with higher HP in mind.
"cooling, oiling, filtering, and the like"=yes, we all want cooler, cleaner oil"
"just slapping on a turbo is likely to cause major problems"-in extreme use/cases.== Did you see the hot VW issue when they "slapped on" a draw thru turbo (not my choice) on the editors "STOCK" t-1 and dyno'd 110 HP without any internal mods? (Not the best plan but indicative of what can be done)
The flywheel to crank mounting is very weak...hence many people require 8 pin or flanged cranks....and extra heavy torque on the bolt....also, shuffle pins on the case, lightened and forged fly wheel (ever see a 20 pound stock flywheel come apart? ====Are you saying that 200 turbo hp blows apart a flywheel easier than a 200 N.A. H.P.?
Rods and pistons are very heavyly loaded in a turbo engine....the seal of heads to cylinders may require special gasketing=="special gasketing?",
need to make certain compression is not over x.0:1....need to know compustion chamber cc's, deck height, and a few other things----
All I'm saying Jim is that by stating the above the way you did implied that I suggested that you shouldn't upgrade the basic engine and perform a quality build because it's a turbo engine. The same precautions/quality should be included in any quality engine build wether it be normally aspirated, turbo or other. What I advocated and still do is that using a turbo motor will perform better all around and the "base motor" can be built to a lower state of tune (compression ratio's, stroke etc...) and get more HP.
If it's not too private ask the owners of the engines who have posted high HP figures what
cost high H.P.---It ain't cheap.
Remember George Brown's (R.I.P.) high H.P. T-1 motor? Tweaked to such a state that the words "unstreetable" were used. A turbo would have given him the same or more for less and been much more user friendly.
"Conversely, if one is to build an engine carefully around a plan to use a turbo, it can be done for not too much money, but it need be engineered for the tubo, not just slapped on top of the old clunker"----I never said slapping a turbo on top of a stocker was a good idea-- But a lot of fun for some that's for sure. Ever see an engine "blow-up" contest at a VW event? Makes no sense to me but very entertaining/fun for some.
I'm sure we're saying the same thing Jim. Any high HP motor needs to be addressed as a total package, put together with care, knowledge and thought. I'm not an expert in anything, jack of all trades-master of none. I can build, weld, wire, paint, drive most anything. Some of it I do well others I give it my best shot. Lifelong mechanic-- aircraft mech(career), auto mech. for fun(less fun as time goes by). Spent 5 years in a VW engine rebuilding shop(sorry, I didn't count "the engines I built") where we balanced, weighed, cleaned and measured every engine that went out the door. So impressed with our thoroughness that it came with a 12 month unlimited mileage warranty.