Monday my Zilla controller arrived. Yowza! One less excuse for not getting the car running.
I spent much of the day happily rearranging the parts I plan to put in a water-resistant box in the rear of the Ghia. I think I have the correct layout now. It will minimize wiring and coolant hose runs and fit all the bits I want to keep dry — the Zilla and Hairball, the potbox, the DC/DC, and the contactors.
There’s a problem — or opportunity — though. The Zilla controller comes in two pieces: the power stage, the one that does all the heavy lifting of feeding battery power to the motor, and the Hairball, which is much smaller and covered with places to connect little wires to. The Hairball makes all the decisions and tells the Zilla power stage what to do. There are several versions of the Hairball, with different capabilities.
You’re way ahead of me, aren’t you? Yep, they sent me the wrong Hairball. I ordered the base version, which senses the throttle position by reading the resistance from something called a potbox, which is essentially a volume knob (potentiometer) with an arm on it that the throttle cable pulls on. What they sent me expects something called a Hall Effect Pedal Assembly, which is a replacement for the entire accelerator pedal that contains Hall effect sensors and wires directly to the Hairball. The Hairball they sent me won’t work with a potbox, so to use it I need to buy a HEPA.
The advantage of the HEPA is no potentiometers. They wear out, get dirty and crackly like the volume knob in your stereo, and stick. On your stereo that’s not a huge deal, but the Zilla equivalent to crackly music is a car that lurches or stumbles. The Hall effect sensors should last pretty much forever with no degradation, plus there’s no throttle cable or throttle springs or separate pot box to deal with.
The problem is that I’ve already spent the money on the potbox etc.
So now I’m faced with trading in the the better Hairball for the crappy one and hating myself in a few years when the potbox dies, or keeping the better Hairball paying more money for the HEPA and feeling smug about it for as long as I own the car.
Hmmm. Looking at my choice of words there, it looks like I may have made my decision.
