Tuesday 14 October 2014

On the Road

The bike is now fully put back together again at last! i.e. all fairings, lights, mirrors, etc. This means I am no longer restricted to testing during daylight hours. A nice addition to have coming into dark winter evenings. This is the first time it has resembled a finished bike since the project started.

Over the last few weeks I have managed to take it out for a few long (2 hours plus) spins while logging and letting the tuning software refine the VE table. I have to say, I am very impressed so far with the injection system and how well it can cope with the wide rev range. Sure there are rough edges and areas which need further development but really I am delighted with the performance of the system. Above 8,000rpm the ride is very smooth and it honestly feels like it was made to be injected. 3,000 to 8,000 was very rough to begin with but over the last few rides it has smoothed out significantly. That area still needs more work but it is rideable. I suspect a lot of the issues at low revs may be caused by the fact I have acceleration enrichment settings disabled and a seemingly small change in throttle in that range results in a much larger change in relative airflow than the same change higher up the rev range.

I also fixed the issue with the Koso dropping revs at high engine speeds. It was simply a matter of changing a setting in the ECU to output the tach signal at half engine speed and then change the settings in the Koso to convert the half speed signal back to real engine speed. It seems the Koso has issues dealing with 2 ignition events per cycle at high engine speeds. Having a reliable speed readout also gave me the confidence to bring the engine all the way up through the revs. It has left me with no doubt whatsoever that the microsquirt can handle engine control at CBR250RR speeds.

There is a lot left regarding tuning the fuel table and then the ignition timing table but it now feels more like a bike and less like a project so that is a big positive.

The next big job on the bike is a new paint scheme. The new front fender and fuel tank don't match the rest of the bodywork.

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