Where does missing tooth on trigger wheel go?
 

Documentation says "You will need to install the trigger wheel so the missing tooth is a specific number of degrees ahead of the VR sensor when the engine is at top dead center"

But "ahead" is ambiguous.

Does this mean that the missing tooth has already passed the sensor before you get to TDC?

Or that the missing tooth doesn't pass the sensor until after TDC?

I suspect the 1st interpretation but looking for confirmation.

Thanks

I just installed an electromotive kit with a clewett crank pulley and trigger wheel. On my setup the missing tooth is before the top dead center point. So yes the missing tooth will pass the trigger then go past tdc.

Which EFI system are you installing?

The missing tooth should have already passed the sensor before the engine reaches TDC on cylinder #1. You should be able to input the appropriate degree amount in to the software for the offset between TDC #1 and where your sensor is located.

The ECU needs to know that it has "X" degrees of rotation before TDC #1 comes up so it can prepare injection and ignition events appropriately. The missing tooth is like a countdown timer before TDC #1 is reached.

Install the missing tooth at tdc and if you are using the going super fast or the clewitt vr adapter it will place it at around 48 degrees btdc which you will verify at initial startup with your timing light

Super. Great explanation. That's what I thought, but I overthink these things sometimes.

Oh, microsquirt. Actually its 60-2 so missing teeth