Any help to understand Aldon Boost Amethyst unit and timing please?
Turbo Mini Forums

Hey, I know I should have went with megajolt and I really regret that decision but not much I can do about it now so gonna see how I get on with the Amethyst anyway the thing I'm not understanding is the boost/vacuum bit. I've set the basic timing for each of the RPM figures and the mini runs fine, no flat spots or anything like that. I set my dizzy to 8 degrees of manual advance and have set the max advance to 18 degrees to give me a total of 26 degrees of advance by 3000RPM. What I don't understand is how to set up the bit circled in red (sorry didn't get a screen grab of my actual map setting), I think it's to do with when I'm driving at full throttle and then shut off the throttle so the engine is still high revving but then theres suddenly no air but I'm unsure on how to do the setting.



Car is a 1275 Rover mini that I've fitted a M45 supercharger and HIF44 carb, I'm trying to get the mini running well enough that it will be able to make the journey to a decent tuner to get set up by a professional because I can't find a place near me. I'm in the SW of Scotland and not comfortable taking it too far yet.

I've never used one but it looks like a simple job of entering how many degrees you want to retard for a cirtain level of boost.

Ah so the higher the boost the less advance I'd want cos of all the extra pressure in the cylinder. That makes sense.

Yeh that's the crux of it. Usually it's done via a table with rpm on one side and load/boost on the other. This setup is applying a 'trim' to the rpm values which is a bit less flexible than a real ecu but still miles better than a clockwork distributor.

That's brill mate, think I get it now. Thanks very much, I'll need to have a play with it cos it feels pretty solid under full throttle but it feels rather shaky when cruising with partial throttle.