Nah, it really is that eddy-current process (electrical sorcery). Methinks the FB/EK speed cup is ally - no magnetic attraction. Couldn't get a magnet to stick to it.Craig Allardyce wrote: ↑Sat Mar 23, 2019 9:12 am Not sure your over doing it Harv. I think its only the magnetic attraction of the cup to the spinning magnet that causes the rotation.
https://auto.howstuffworks.com/car-driv ... meter3.htm
I finally got a chance to test run the car last weekend. Confirmed it was legal with the RMS, then took the car for a squirt up the M4. Number 1 Son tagged along, and took notes comparing the speedo to one of those fancy iPhone speedo apps. The EK speedo was out by a nice, consistant 10% (not bouncing around anymore), and reads too slow (not reading too fast anymore). The speedo error is almost spot-on what the TCI website calculator said it would be. I changed speedo gears from grey (22 tooth) to blue (20 tooth), though haven't taken it for another test-run.....
..... because the car decided it was not an EK wagon anymore. It is now a smoke machine.
Halfway back along the M4, and smoke started pouring out the back of the car. My fancy new transmission oil cooler had come adrift, and ATF was leaking onto the headers. Limped the car home (just), and found the culprit. I had installed one of the cooler hose clamps cock-eyed, and it had let go. Fixed the hose, and cleaned up most of the spray from under the car. Driveway test run shows no leaks.
Cheers,
Harv