Well, I left out a couple things to save time on the list, such as their intake manifold, injectors, straight piping after their header(ie. almost no backpressure), their cams, which if you do enough looking can be found in the US, and in fact were featured in an old issue of sport compact car, they also run 11.1:1 compression with use of the stock JDM ITR pistons, and they also run their timing pretty far advanced, which yes along with fuel is controlled by the ECU, but if the ECU thinks you have larger injectors, when it dumps fuel, it's not putting up as much as it thinks, in addition, with timing, they also run either 97 which is pump gas in japan or 100 octane gas on race day in their cars for N1 races, which means on the street, it runs a lot of advanced timing, which on pump gas especially if you live in cali, and have 91, will cause your car to ping majorly. Thankfully our compression in the states(10.6:1), is low enough where it won't make all that much difference, but either way, the point I was trying to illustrate was, that the NI ECU was made for a purpose built race car, and slightly adapter for US street cars, but the parameters it uses aren't that conducive to a street car, your far better off, for like half the price to go get like a skunk2 program.

It's a good ECU, don't get me wrong, but just keep in mind, as with anything else in cars, just be prepared for what else you may go wrong. Nothing is foolproof, and you should take as many precautions as possible. On that same note, if your switching valve springs, at the same time you really should switch to Ti reatainers.

Good Luck,
Aj