So I decided to upgrade the ECU to a Motec M800 as the M400 really did not have enough control and enough options around servo control for the Exhaust valve.
More assistance from Neil in the UK as you need to purchase the correct licences from Motec to upgrade and expose parts of the software.
Remembering I needed really good DC Servo control and digital solenoid control for the power jets as well as the throttle position , RPM and gear position mapping.
Oh and a quick shifter if possible. The M800 enable me to have all this control..now all I need to do was get my head around how to program this.
PID Control
Because I wanted the precise control of the exhaust valve as this is really the heart of the performance of a two stroke to give you controllable power basically these bikes are unrideable without precise control. The KR3 had a reputation as one of the nicest engines in the two stroke era so I wanted this control and options.
DC Servo control is all about PID.
From Motec. (They have loads of tutorials etc.. )
What is PID?
PID stands for Proportional, Integral, and Derivative and is a type of feedback control system. It compares a measured value (from a sensor, say) against a desired value (the setpoint or aim) and adjusts outputs to reduce the difference (error) between the two.
The controller (or ECU in our case) uses a constantly updating calculation to control a physical system. It looks at the current value of the error, the integral of the error over a recent time interval, and the current derivative of the error signal to determine not only how much of a correction to apply, but for how long.
Started testing this but had to start the bike each time which was a pain.. -> Grandads scooter and the lads!
So worked out I could map against another input for testing.. so used throttle position 0-5V signal to replicate the RPM... made for a lot easier testing. Hours of fiddling, more reading...understanding PID... really interesting subject btw and used in all control systems. Got it a stage where I had a few options to test.
Off to the track
I thought it was now good enough to ask Aaron Slight the ex World Superbike rider and the most experienced world class rider I know!.. an absolute privilege to have him agree to test the KR3. S
The number one thing was safety.. these bikes are old and fragile so needed to be super careful with preparation. New tyres, warmers etc
Off to Manfield again and this time with my old boss in tow!. Mike Sinclair another legend of our sport so really didn't want to **** this up!
Assemble the team again.. Ashley, Sam and Veggie and off we go.
Mick Ruane from Palmerston North arranged and paid for a garage for us to work in.. very generous!
The open day at the circuit were also generous and gave us time slots etc to run.
Ended up making a pretty major change to the mapping with the M800 at the end of the day (based on some more understanding of Motec systems) and made a significant step forward.. now running well and Aaron very impressed with the handling, nimble and powerful.. phew.. a big relief!
Data recording now working also although had to get my head around all that .. a bit of jetting...power jets I left on as quite concerned about nipping it up in the cool weather.
Successful day!
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