Any questions you have before you begin buying, building and installing.
#58096
jonbill wrote: Fri Aug 12, 2022 7:16 pm No, I think @psig just misread it, assuming you were saying 1 is at 90° and 4 is 180° later at 270. it's odd fire.
I suppose that's possible too.

The reason I originally came to the odd-fire determination is because the current pulse wheel only has 1 tooth. And two pulse generators placed exactly 90 degrees apart(one directly under each bank), which leaves 270 degrees with no pulse events.
#58119
So one more question.

In this configuration using wasted spark and paired injectors; how much does it matter for amount of trigger teeth?

I mean 8 vs 12.

Here’s why I ask…

A 8 tooth wheel can be purchased for $20-40 from a VTR250.

A 12 tooth wheel can be purchased for $170-210 from a VFR750.

I’d like to know the pros / cons due to the price difference.
#58120
more teeth means better accuracy of injection and ignition events, at the cost of more CPU cycles processing teeth. There's a point as revs rise where there aren't enough CPU cycles available to do the processing in the available time.
not sure where that limit comes, but I think in practice 36 is a great number.
in your case, I think it worth paying for a bit more for 12.
#58121
+1 to @jonbill

Though, I will also add that when dealing with small diameter trigger wheels, you need to consider the sensor.
The wheel stays the same size, but as you add more teeth, those teeth get smaller. So, to many small teeth could lead to the sensor reading the next tooth before it has finished reading the last tooth. So some caution there :)

I think the way forward here, is to try it with what you have (or have already suggested), and go with it. It will run. Then think about if you need a higher definition on the trigger wheel.
#58300
Just wanted to add an update to this point.


12 tooth trigger wheel arrived. (Need to pull the engine and get it installed and start working on throttle body stuff)

Got the Pre-Ignition X2 and have it all ready to go: (Did a bunch of bench testing just to make sure things work too)
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#58659
Crank trigger designed and done! (The VF700 wheel didn't work as planned)

Sent out to be made in 4140 steel already.
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