i did got it cheap and works so each to there own
Greetings and what a way to start a first post.
I have been using the Nikko Racing G-Pack unit on my 04 ZX-10R for over 3 years with no problems. It works in tandum with the PC3, advancing your ignition timing in the 2nd and 3rd gears for smoother throttle response. You will feel it especially at deceleration in these gears. It costed me quite a bit when i bought it back then in 2004 (250 euros!) as the kit consisted of 2 pieces but I was advised by some local racers that this was the quickest and cheapest way of removing electronic factory restrictions. The bike goes over the magical 299km/h and has been clocked by a mate's 00 12R to max out at the top speed of 305km/h (on his speedo).
Recently, I have had the opportunity to acquire a used 04 10R KIT ECU for a fraction of its original price. I removed the G-Pack in preparation for the installation of the KIT ECU and i couldn't believe how jerky the bike felt in the lower gears when i had the chance to ride it afterwards. Spoiled by the smooth on/off in my lower gears with the G-Pack, I almost though something was wrong with the bike.
I believe the justification of the G-Pack's cost to be that of its ability to actually advance your ignition in the 2nd and 3rd gears without the need of either the KIT adjustable ECU, dynojet ignition module or any other form of ignition tempering. Removal of the G-Pack resulted in an overly RICH fuel mixture in my lower gear mapping and obviously, installation of the G-Pack will be the direct oppersite. Here's when a PC3 really comes in useful to tune up that boost (or drop if you're removing the G-Pack) in fuel mixture.
Make no mistake, the G-Pack does work. Throughout the months, I have seen many bike owners avoiding the G-Pack due to its high cost (9 times of a TRE!). This is understandable as 250 Euros isn't what most people would spend on 2 little black boxes. However, these owners often or not, try out the TRE (which tricks the bike into a 5th gear ignition/fuel mapping in all gears), become impressed with what the TRE does to their vehicles (smooth throttle on/off), and come back labelling the G-Pack as an overpriced rip off. That IMHO isn't right. Both products are effective and work just like they advertise they would. It's really up to what you want for the bike.
G-Pack: Retains stock ignition/fuel mapping for 1st, 4th, 5th and 6th gears. Ignition advance in 2nd and 3rd gears resulting in smoother throttle in those gears. Removal of top speed limiter via speed sensor tempering.
TRE: 5th gear ignition/fuel mapping for all gears. Does not retain stock ignition/fuel mapping and as a result, smoother throttle utilizing 5th gear ignition/fuel mapping will be experienced.
In a nutshell, the G-Pack removes all factory restrictions and retains the stock fuel/ignition settings that define your bike's power delivery.
The TRE removes all factory restrictions too but you lose the power delivery KHI intended the bike to have simply because the bike runs the 5th gear ignition/fuel map on any given gear.