- Jul 25, 2014
- Olympia Washington
- '14 R3R, '02 Daytona 955i
It's probably simply running into a current limit situation.
When discussing this off-line with @Joesmoe
although however there is the factor that the drive transistors could be suffering some thermal conductance limitation, as they will certainly run hotter as the frequency increases (because there is less 'relief' time before the next cycle, so heat will accumulate more - so could be that ...)
I have my suspicions, however, I'm going to replace the coils anyways for good measure when I strip out the Triumph equipment.
Incidentally, it'll give me a chance to open the ECU and actually take a look at that circuit and figure out what IC (ICs) is/are responsible for coil charging. If this is a single MOSFET for all three cylinders, as I highly suspect it is, then it makes sort of sense it is struggling to keep up at high frequency, during high temperature and at high current load. At 8500 RPM, that single MOSFET will be responsible for 12,750 charging events per minute, 212/second, equating roughly to a 20% duty cycle, not a problem for a good 105c chip like you'd find on a top tier motherboard, very possibly a problem for an 80c/85c rated chip, depending on which they used.
Should be fine, but should and are, often don't play nicely as you well know.