Thunderace EFI - Day 8 using MSExtra 3.0.3u

Another trip to the bike today and another "cold" start, but it was slightly warmer, and I needed a little throttle to make it catch. I started TunerStudio on the laptop, and after I had burned the condensation out of the pipe, I fired up the Innovate LC1. I was sniffing & watching the AFR as it got up to operating temperature, and at the same time tweaked the WUE & ASE curves to maintain stoich (AFR=14.7 to 1) give or take a bit.

I disabled the acceleration enrichment, made sure all temperature related stuff was not adding corrections, and although I can’t say the methodology is perfect, it is appearing to work.

One thing I did notice, the engine was hugely rich, and it had me confused at first, and after looking at some video my pulse width was fluctuating. I suspected some compensation circuit was doing it, and it turned out to be the battery voltage compensation for the injectors was causing most of it. As the voltage climbed (battery charging) the engine was getting richer, so I leaned it off on the VE Tables until I reached stoich, and then waited for the voltage to climb again, which made the engine richer still. I adjusted the ms/V figure downwards, until the engine was more consistent, in that battery voltage increases (as the on bike battery charges from the alternator) were not causing excess richness.

Next up, was part throttle response and adjusting the VE Table to suit. I was quite surprised by the numbers, as the engine needed less fuel than at idling to make stoich, and by adjusting the speed density map too in VE Table 2, actually made the engine smoother.


By now I had worked the engine for about an hour revving it upto 4K rpm at various small throttle openings, and there was a definite improvement in part throttle response as a result of todays work. Unfortunately, there is only so much you can do without upsetting my friends neighbours, so I had to finish.

Overall I am still well impressed how it is going so far, and the cased MicroSquirt, TunerStudio and the MSExtra code is working very well together.