Been a long time...
Busy at work etc, but have managed to get some proper consultation with the auto engineer here in NSW which is paramount before getting too deep into it. Converting pre 1980s minis here is fairly ok as they had limited to no requirements. My import 1994 mini is a little more tricky. Easy enough to keep the catalytic converter, but the charcoal canister and purge valve is proving to be a pain. The R1 engine, thus ECU, do not have a control for this. I initially thought I would wire it up to ignition live and plumb the valve into the airbox (which I will have to fab). Seems this will not fly, as it is not the way they work and I can't demonstrate with evidence a working example of this.
Charcoal canisters need vacuum to strip the hydrocarbons off the charcoal. So, OK, plumb it into the vacuum lines on the throttle bodies, but the problem there is that if I do it on ignition only it will mess up idle if the valve is open. The purge valve normally only opens during cruising throttle and is closed at idle and what. I could run an aftermarket ECU like Haltech, but we talking millions of quid and mapping on top.
Thoughts at the moment are plumbing it into the throttle bodies and run the purge valve on a relay, and have the live feed triggered by a switch on part open throttle somewhere, maybe on the pedal assy. It would be momentary, but activated enough to be essentially effective as intended.
Other feedback is the requirement for a "drive by" noise assessment. I'll muffle the heck out of the exhaust, but hopefully the reverse gearbox and chain drive don't make too much dB.