Got busy with the aluminum and roughed out the rest of the enclosure. With my simple tools, making a well fitting 1/8" aluminum case is a bit tricky, so there will be some rough corners.I built it to screw together at this point,with the idea that if it needs more rigidity, the screwed together joints could be TIG welded.
The air handling system wants to allow lots of air flow. This gets tricky when you look at the present pack inlet air side where all the air needs to pass through a small louver behind the passenger seat,then take a couple of corners, and pass through the narrow slot where it passes through the IMA box sidewall. Finally it expands out to the full pack inlet.I decided that 3 - 3" fans tucked right in the inlet duct should suck in a much bigger flow of air. On the outlet side, instead of trying to suck out the air with a single fan,I would add 2 more 4" fans directly on the outlet side, and eliminate the fan shroud completely.To control the fan noise, I will build in a temperature controlled PWM fan speed control. The HV connections on the relay board will have big wires attached and will feed into the terminal side of the pack. The cut off relay panel is secured to the pack in exactly the same position as on the stock pack.