Unless you stroke, for now the only way to get 300 NA (on a roller dyno) is to use ITBs.

 

You need to expand your horizons a little and look at the problem from an engineering standpoint. There's nothing "fake" about forced induction. Arguments like that walk hand-in-hand with carburetor vs fuel injected arguments.

Anyway, there are basically four ways to produce increased power (in comparison) in an internal combustion engine:
Increased displacement.
Increased RPMs.
Increased compression ratio.
Forced induction.

The function is the same - moving a greater volume of fuel/air per given unit of time. They all do it. However the most efficient way to do this is through turbo-charging (the second being mechanically-coupled supercharging).

More and more modern vehicles are turning to turbo-charging due to the greatly increased volumetric and specific efficiencies gained through their use (Audi, VW, Porche, Volvo, Saab, BMW, Acura...).
Turbos weren't widely used in the past due to the complexities associated in system design and control, making them much more expensive and prone to failure than N/A designs.
Modern design, production and control systems have made turbos much cheaper and much more reliable.
If done in moderation (~350whp), you can turbo-charge your S2000 without having to modify anything outside of the plumbing and engine management associated with the turbo kit itself.
However, if your intent is to impress people with your dyno printouts - you'll need to invest a lot more in your car to keep it running reliably long-term.

 

Inline Pro made 300whp on thier 2.7 stoker kit with stock header and intake.

 

is the stroker kit only for the more rescent S2k?

 

What is the "more recent s2k"??? a stroked motor is a stroked motor honda didn't change the engine compartment.

And to the OP and some of his posts, please do some research in the FI forum and post the phrase "in the back of my mind, that the FI is faking power" and see what some of the guys say.

 

sorry I should have said "does it work only on the 2.2L s2000"

 

No such thing as fake power, results are results.
For the longest time I used to dog people who use Nitrous, but in theory for a lot of people it makes more sense. It cost less for a properly tuned nitrous setup than say a supercharger, and you can switch it off when you don't need the power (however, if you're constantly tracking your car, makes more sense to go with FI cuz you don't have to refill the bottle, so again, apply as appropriate). I think it rubs people the wrong way, including me, because it kinda takes away from the whole aspect of knowing and working on cars and engines and such; anyone could just slap on a nitrous kit. But these days, people aren't piecing together turbo kits and fabricating makeshift parts and such, most peopel buy kits and have shops install it and tuning it.
So in regards to your view of NA vs. FI, I appreciate where you're coming from, but if you're looking to make more power plain and simple, go with the most cost effective way.

 

A 400whp turbo build can be done for 2/3 of the price of a 300whp NA build. However, the only place the turbo car will have the advantage will be in a straight line. The NA car will have much better engine response and a flatter torque curve. My favorite combo is a built bottom end, supercharger, and nitrous. Slow Motion built an S2k to 528whp with a fully built motor and a supercharger. It also had a 200 wet shot, making over 650whp with nitrous. I had a 500whp turbo setup that was pretty sweet. GT35r ball bearing turbo, 750cc RC injectors, JE pistons, Eagle rods, spearco 600hp intercooler, Walbro 255 fuel pump, custom manifold, tial wastegate and BOV, etc. The only problems were, lots of maintenance, didn't run the best on pump gas, straight line car. However, with the GT35r ball bearing turbo, it spooled a little above 4000RPM. PM me if you want to know more about the turbo or SC setup.

 

Turbo cars are light years more reliable then they were 20 years ago, but they still fail at a greater rate than NA cars. NA cars today, from an engine standpoint, are almost bullet proof. Money shifts not withstanding.