I'm going to sound like a broken record because I have said this so many times but I am going to say it again. Lets back up a bunch of steps:
In general, the purpose of buying a sports car is that a sports car is more fun to drive than is a standard poor-handling, slow-accelerating, numb-steering-feel car. I think sometimes you have to ask basic questions... why am I buying this car?
So most guys then get in this dilemma, like you find yourself in... how much performance can I buy? I am sure if we all could have Veyron acceleration and FXX handling, no one would say no. You want the most performance, because... you think that will be the most fun. But this is a myth. There are many cars that are very fast, but not that fun. If your car accelerates hard but the steering feel is numb, that's not fun. If the car has great performance but looks kinda ugly, that takes away from the excitement factor. If it has a great engine but the exhaust note is that of a UPS truck, that's no fun. If the car has great performance but you are forced to drive 35MPH in traffic, that too, is no fun.
Part of the appeal is the sound, the look, the design, the pizazz. Right? It isn't just about speed. This is part of the NSX's draw, its sex appeal. Now, you are sitting there like I did years ago pondering the purchase of a car, looking at the NSX's slinky body, and wondering if 300 HP will be enough for you. Right? I had a Comptech Supercharger on order BEFORE I took delivery of my car.
I put the CTSC on, and HOLY COW... now I could take off at the stop light like a bat out of hell and probably outrun most cars. Of course... it never really ends, then you need the next mod, the next set of wheels, etc.
Last week I had my 17th day at a racetrack. I went to Watkins Glen with the Ferrari club, and can tell you for sure that my supercharged NSX was probably one of the slowest cars there. In the hands of my instructor, my slow NSX could probably LAP the fastest Ferrari there. You soon realize that a bone stock NSX is FAR superior to what most drivers can handle. One has no idea how bad of a driver he really is until he is out on a racetrack with pros. Does it really matter if you have 550 HP but a better driver can school you in a 200 HP car? I am asking...
Suppose you have 600 HP in your car. What do you do with it? Race a Vette at a stoplight down Santa Monica Boulevard? OK... it's fun for about 20 seconds... unless you get busted. What else can you do? Put your girlfriend in there and as you enter the highway hammer the throttle and have it suck you into the seat... right? pretty cool... she says "wow"... OK... 10 seconds of fun are now over. Maybe you want to find a stretch of road and see how fast you can hit 150?
I am just trying to bring up any and all scenarios as to why people want 500 HP. If there are others, please chime in.
Now I can tell you first hand, and I am just a newb, that taking a car that is truly capable like an NSX on a real road course is about 15 levels up from doing any of the shit we mentioned above. It's then that you start to understand what real fun is. It's there that you go through an experience few people go through, because they are still busy modding a car they already can't handle well. It's there that you understand that "fast" has very little to do with horsepower.
I am really going off on a tangent, but I am trying to make you think a little. The NSX... in stock form... is faster on a racetrack than many many many cars. Do you want to know what that kind of fun is like? It is a rush that cannot be equaled even if you put 800 HP in your NSX. Imagine the height of your thrill when you take an off-ramp fast or accelerate hard out of a corner, multiply it times 5, and make it last 20-30 intense minutes at a time. That is what will happen when you have an NSX on a track. Even here on prime, few guys will ever appreciate that. And so the forums go on... about if a turbo is better or a supercharger is better.
To answer your questions:
1) No, you cannot just unbolt stuff and expect the car to run. Your entire fuel management must change with it. What you propose is extremely impractical.
2) I think most would agree that you are putting SERIOUS strain on the motor going much above 400 HP on stock internals. And that is not an on/off or strain/no strain switch set at 400. The stock internals by Honda were designed to go 300K miles easy with 250 or so WHP. Push that to 350 with a CTSC, and you are going lower its life. Go to 400, lower it even more. Or you can try 450 for a few weeks. I'm not against power... I would LOVE to have a 550 HP turbo... but try to go cheap and you will pay with a new engine.
3) building a motor with stronger internals will not affect emissions, so long as you do not alter the bore/stroke or engine management.
** This part is my opinion only ** : To me, the Comptech supercharger is the simplest and most reliable FI system there is. There are tons out there with many many miles and many are driven on the racetrack. Can a turbo be as reliable or even more so? Of course! But not on the cheap. The Comptech system also has the most NA like feel, and the most NA like power band. A stroker motor can be the same, but it is expensive, it is NOT SIMPLE (contrary to what many think), and it is just a bit shorter on power. A turbo also will generally not have the same flat power band as a roots type supercharger from 0-8K, but there is something to be said for all the extra power and torque it produces. Linearity only goes so far... It's like a girl with a terrific personality... you know what I mean?
Even if you try aftercooling the supercharger, you will immediately get into much more complexity. An intercooler, a heat exchanger, a water pump and all it's related lines. The extra power now requires fuel management, injectors, fuel pump, tuning. The cooler has to sit between the blower and the engine... imagine the heat it must dissipate... and as the engine works harder, that cooler becomes less and less effective. These are just compromises. Every design has compromises.
So what I am advocating to you, is just take your NSX to the track one time. Take it there bone stock. If you leave and feel the car is slow and you need 500 HP, then I will eat every word I have ever written. Start there. Start at the place where this car belongs. Then you will know how to mod, when to mod, and when and at what point you really do need 500 HP. The next time you are at a meet and a guy says "This car isn't fast, it only has 300 HP" ask him if he knows how to double clutch, heel and toe, rev match and drop down two gears heading into a right hand turn after hitting 135 on the back straight.
I just realized this reply is the longest I have ever written in the 5000+ posts I have on prime. And you don't even own an NSX. :wink:
I would have the sos kit hands down, no question. All other kits seem to have charge pipes lazily hanging down from your motor at a very low position. I cringe at the thought of driving over a dead animal with something like that. 
