Your buddy needs to find his ...
Back in my previous life, how I put myself through college, I was a marine master mechanic for a little group called the Gentry (Bernie) /Mercruiser racing team who built race boats so I know a little bit, but have forgotten most of it.
Engine timing and fuel injection timing/amounts are the things that the ECU affects while the TCU takes care of shift points, etc., in the transmission.
In order to make massive more horsepower you need more fuel and air. The engine needs to breathe better which means better intake, better exhaust, better camshafts (without cams all the exhaust and intake enhancement is very limited and why the ECU reflash is limited to what it can provide) better compression ratio and then the hopes that the crank, rods and pistons will tolerate it as well as the heads and block... Thats why Chevrolet two bolt main blocks get drilled and capped for 4 bolt mains, to give the block more rigidity and to help keep the crankshaft from being able to flex or break.
People use forged rods and/or forged aluminum rods and forged pistons and that is why some Maserati's put out a puff of blue smoke when you first start them as forged pistons expand more than cast pistons and therefore have more tolerance in the cylinder as they expand more when they get hot. Cast pistons are usually fitted with .003 to .004 thousands clearance while forged are fitted with .005 to .008 clearance.
This is all in the case of a normally aspirated motor. Bolting a supercharger or turbo on is easier but the main components of the engine need to handle the additional stress added by the pressure, either way you are looking at much faster wear on the engine.
The major difference between our 4200cc engine and the 510hp 4300cc F430 engine is the heads, valves, camshafts, intake, exhaust, compression ratio and the ECU. If you want that kind of horsepower, it's a bolt on operation if you want to buy the parts. The difference in the engine size is in the stroke and not the bore from what I remember.
The guys at formula dynamics have mapped everything that is possible so if they are not getting it, chances are others are not as well.