Huge picture post!
The car is off the register for the winter, and I had some time to start planning for longer term upgrades. This is what the engine room looks like now, tools and parts everywhere
I have several parallel projects going on now; main one being the Megajolt installation. But I also am working on a hardware and code for my custom electrical speedo, and I'm planning to get the heater plumbed in for next year.
The Megajolt itself I divided onto several tasks, the difficult ones being the trigger wheel / VR sensor, and TPS sensor. I spent hours researching different solutions, with not too many results, sadly. Caterham forums (blatchat) are a massive archive of information, but they are rather old school and don't believe in posting pictures
There's only so much one can figure out by text descriptions. And I can't even post there without a lotus club UK membership (which is way too expensive just for the forum). I did find some possible solutions, but nothing ready to be applicable, so a good amount of improvisation will be needed here. I hope someone with similar problems will one day find this thread and find all my pics useful, I certainly would have!
So... the TPS. It's needed to have information of the engine load for the brains. There's no straightforward way to mount a Ford TPS on my Weber DCOE, but Webcon makes a bolt-on kit. Sadly it's something like 90 GBP, which is insane for a 5 kohm potentiometer in my mind, so I tried to replicate their
solution. Since my Ford TPS has a little
lever, I made this little fork out of the small angle piece of brass I found laying around. It goes on to the throttle spindle of the carb, and it's keyed so it stays in one orientation.
Mounted:
This is the idea, the TPS stays in front of the spindle and its lever is rotated by the little fork with the throttle. I still need to design a bracket to hold the TPS itself, it will probably be bolted through the hole on the left from the spindle.
I also received my trigger wheel, so I went ahead and tried to test-fit it. First I had to undo the bolt which holds the crank pulley. It shouldn't be too tightly on (40Nm iirc), but since there's no easy way to lock the engine on the xflow, it caused me some trouble. Also there's very little room to operate the wrench, chassis tubes everywhere around. In gear, handbrake on - too much springing, couldn't undo the bolt. Then I remembered reading about the rope-trick. Basically one rotates the engine until a piston is on the compression stroke, stops before reaching TDC, and... stuffs the cylinder with a rope through the spark plug hole. The rope will hold the engine from rotation by preventing the piston from reaching the top. Genius
So I did that. A meter of nylon rope in cyl1:
It worked amazingly well, I got the bolt opened right away.
As I was removing the pulley and saw the familiar orange oil shaft seal, I panicked for a second looking for a catch can, but then realized that the crankshaft is not submerged in oil
Diiirty...
Pulley is out, here it is next to the trigger wheel:
The trigger wheel is bolted through the pulley with a longer bolt, and there are just enough spacers between them to keep the pulley in. There's a very slight gap between the pulley and the trigger wheel. Later, the trigger wheel orientation needs to be fixed, so that the missing tooth is at a certain angle from the VR sensor when engine is at a TDC. I'm thinking of drilling through the wheel and the pulley and connecting them with a thin bolt. Maybe in two places to keep it balanced. Some people also weld them together. The pulley itself is keyed to the crankshaft, so it's a good reference.
Then I started looking for ways to fix the VR sensor. Removed the water pump pulley to have more access. This is what the front looks like. Two circled bolts are the ones between which I plan on putting an angled bracket which will hold the VR sensor. Upper bolt holds the water pump, and lower one holds the timing chain cover.
I fashioned a piece for test fitting from some thin alu sheet I had laying around, just to get an idea and measures right:
Same with a VR sensor hovering approximately in the right place
It should have 1mm gap between the tip and the wheel teeth, which will be adjusted with washers on the bracket.
Now to make brackets for both sensors from something sturdy.