aha...you keep arguing against something I NEVER EVER said. Is this to make yourself look good? nope just to get you to show us all how a professional engineer should conduct personal behavior over an interenet forum I have no problem with a good discussion..but when you start arguing against things I NEVER EVER said...it's kinda childish isn't it??
Never ever said you couldn't have significant gains in an engine...what I said...and what this whole discussion was about...was getting significant gains from simple mods like a K&N air-intake system or a new exhaust. Significant gains from those type of mods are NOT going to happen.
Turbo charging an engine like the one you show above...yea..that's a great way to get great hp improvements. In fact if you look back at my earlier posts I even said so. Supercharging is also another great way to increase HP. There are probably many mods not yet listed...but that's NOT the discussion. Most if not all mods that are going to give you great gains are going to cost you significantly...or won't meet emissions....or both. It would be far cheaper (but less fun) to buy a vehicle with that kind of hp you wanted in the first place. The other problem with some of these performance mods is it puts significant strains on the engine. You run the risk of greatly reducing the longevity of the engine. Not saying that's a bad thing..but something to keep in mind when doing those mods.
I have installed a supercharger on a friends 1969 Trans-Am (Pontiac Big Block 350). The gains were extremely significant. I think he actually cut 3-4 seconds off his best quarter mile time. The cost back then (1974) was well over $1000. That's a months pay for a decent job back then.