S12 Crank Trigger Setup Questions

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lt1pat
Posts: 1
Joined: Mon Mar 08, 2021 5:49 pm

S12 Crank Trigger Setup Questions

Post by lt1pat »

What I know:
The Viper V10 engine is an odd fire with the drivers bank 90 degrees and the passenger bank 54 degrees. The crank has no missing or added teeth to identify the start of a rotation, the signal comes from a 1 tooth cam trigger. Both the crank and cam are falling edge triggered. A crank reference angle is roughly 93 degrees.
The crank trigger has 5 groups of 2 falling edges. Each group has a 18 degree separation. People with other ECU's call this a "20-2-2-2-2-2" pattern.

Image

Here's my initial guesses on how to configure the software for this:

Fundamentals:
Firing Order - 1-10-9-4-3-6-5-8-7-2
Bank Allocation 1-2-1-2-1-2-1-2-1-2
Asymmetric Engine Flag - Yes
Asymmetric Cylinder Positions - 90-54-90-54-90-54-90-54-90-54, or should this be increasing like 90-144-234-288-378-432-522-576-666-720?
Crank and Cam Type - Generic - Keyed by single cam

This is where things get fuzzy...
Generic Crank and Cam Setup:
Number of Crank Teeth - 10
Number of Crank Teeth Gap Definitions - 10 ?
Crank Reference Tooth Angle (ATDC) - 93 ?
Crank Tooth Gap Widths - Not sure about this one. It has 10 fields to enter (0-9, because I selected 10 tooth?
Crank Tooth Gap Minimum Widths - Not sure, It has 10 fields to enter (0-9), because I selected 10 tooth?
Crank Tooth Gap Maximum Widths - Not sure, It has 10 fields to enter (0-9), because I selected 10 tooth?
Crank Tooth Gap Repeats - Not sure, It has 10 fields to enter (0-9), because I selected 10 tooth?
KulinPapa
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Joined: Wed Jan 15, 2014 8:21 pm
Location: Hungary, Central Europe
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Re: S12 Crank Trigger Setup Questions

Post by KulinPapa »

Hi! Did you managed to setup this trigger right finally? What was the solution?
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: S12 Crank Trigger Setup Questions

Post by stevieturbo »

Have you contacted Syvecs support ?

Have they ever used this on a vehicle before ?

Can't help a lot, but from the help file, it does look like the asymmetric firing angles would be counting up to 720 as you have from 90 to 720

10 teeth and 10 gaps seems sensible

Gaps, I guess 54/18/54/18/54/18 etc ? to add to 360

ref tooth angle would depend on where Cyl 1 TDC is....but with that wheel it could be either cyl 1 or 6. Not sure how to pre-empt that without a known angle from TDC to whatever tooth edge ?

For max/min gaps, other maps seem to go around 50% up, and 50% down from the actual gap widths

gap repeats...haven't a clue lol.

It can also be handy for references to set up a pressure transducer in cylinder 1 and log this to view against the crank/cam triggers.

Some better instruction on setting up crank/cam would be good.

https://www.youtube.com/watch?v=xQcv9YK-DQ0

Also worth asking here, it seems to get more users and there are a good few in the US so more chance of Vipers.

https://www.facebook.com/groups/529817494434981
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