Okay, an area where I have much learning to do is with the ignition. I understand the basic concepts, but that's not enough for really tuning this stuff to the level that I want to achieve. Like Matt suggested previously I need to get the programable version of the HPI kit. That's actually one of the reasons I've invested so heavily in HPI--you can program it.
Here's the ignition curve of the HPI.
The stock setup is to have the Derbi engine set to about 23° BTDC (before top dead center). But how does this compare to where the engine gets on the pipe, and peak power, because isn't that where you want to set up the curve to function? Well I don't have the data on this engine to know. This is a new combination for me. But I do have what I ran previously on this bike. Norcal Cycles does an annual dyno day. It's a blast. lots of different bikes show up. I'm of course the only goof ball to show up with a two stroke.
Here's what the 45mm stroked Airsal Xtreme did with a 24mm PWK, Metrakit ProRace, and the HPI set at 2mm BTDC. From this chart, and by looking at the curve chart we can read that at peak power ~13.5K the bike had ~5° of advance, and at ~9K where the bike starts getting on the pipe there was ~15° of advance. Which my friend Tyler should be ~16° of advance when the bike gets on the pipe, and 20° at about a 1K idle.
Tyler also mentioned that the HPI mini rotors that he's worked with should be checked with a timing light, because he's found that the markings aren't particularly accurate. So all of these readings should be somewhat suspect, because I set everything mechanically, and didn't run it with a timing light. I didn't know that the mini rotor had this feature.
And because you'll want some sexy, here's what the bike looked like that day.
And what the ignition was set to on the bike.
Interesting how the older version of the HPI had a different plate.