Lets clear up a few falsities here. The larger SOS blower does not inherently produce ANY more power than the Comptech 1.7L. The extra power comes at higher boost levels.... which absolutely REQUIRES aftermarket fuel injectors, aftermarket engine management, tuning, fuel pump, and in some applications, an intercooler and heat exchanger which costs $2700 more money. The extra "$500" does not take into account any tuning, which is absolutely necessary when running this kit. Also, the Comptech kit comes with a new triangular brace that is $650 extra at SOS, and a new targa cover that is $1000 extra at SOS.
If you simply swap from a 1.7L to a 2.1L, and keep it at the boost level the Comptech 1.7 runs with to start with, I doubt you will see any more power if not less power but I am certain this will be argued. There is such a thing as proper blower sizing for a system just as there is with proper turbo sizing. So if you are under the impression that 2.1 is better than 1.7, you really aren't understanding how blower sizing works.
In the end, these are two vastly different items, as I said before. One is a 50 state legal bolt-on, the other is a comparatively elaborate system that requires either a compromise piggy-back fueling system like the FIC, or the more accurate AEM EMS that is only for older OBDI cars. Either's reliability rests in the hands of your tuner.
I would never say "you may as well go with".... Because to many, legality, simplicity, and no need for tuning at a lower safe boost level matters a lot. The Comptech system will net you 80-100 HP alongside other mods like headers, exhaust, and intake. That's plenty for a lot of people. It made my car fast enough to stay competitive with Z06's and 911 turbos on the track. On the dyno with headers, exhaust, and intake changed I netted an increase of 112 HP to the wheels.
If you want to jump beyond that, IMO it is almost not worth it to try to make a supercharger work. If you take into account the extra cost of headers and exhaust which come standard with many turbo kits, you will actually spend less on a more powerful, less parasitic turbo system that will give you more torque. Turbo lag these days is minimal, the only loss you may have is one of sound. But once you add up the $, you will see the turbo system gives you a lot more bang for the buck. The position of a blower on a hot motor (intercooled or not) is a compromise. There is some power loss due to heat soak with all supercharger systems. This is something else you do away with on a turbo. The NSX motor is also very high revving and that also is a good match for turbochargers. When boost comes in at 2700 and you have another 5300 RPM's to go, that is a benefit. Low RPM motors have some benefits using blowers.
In short, the only bolt-on system is the Comptech system, then there is everything else. Those are the FI systems that are more comparable to each other and worth discussing in a thread. For those who have decided they are willing to take at extra big step.
