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It is about time.

Dudeland

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 First of all,  thanks to all of those who have supported me through this project.  It has been fun and challenging, but not being able to leave well enough alone, I have embarked on incorporating the timing function of the Sniper EFI into my build.   What am I hoping to achieve by this... no clue.. if I were forced to give a reason... I guess I would say because it was there,  and life is too short to ponder things that satisfy your curiosity. 

 

So after consulting a lot of people, and getting quite a bit of apparently conflicting advice, I think I figured out the answer to a long-standing question.  Why can't I use the dizzy and fool the EFI into thinking it was a crank trigger.   In short, I can emulate the signal or the spark distribution, but not both.  

 

A longer explanation is that you need to give the EFI enough warning in order to trigger the ignition based on your timing table.   This is a critical angle, and the dizzy can't tell the Sniper when to trigger.  And I quote from the manual. 

 

"Once these steps are completed, the rotor will be pointing to the cylinder #1 terminal on the distributor cap (ensure the engine is still at 50 degrees BTDC on the compression stroke on cylinder #1). Note which position this is on the distributor cap."

 

So this 50-degree angle means that the system gets an idea where the crank is ahead of the trigger event and can do what it needs to do, then trigger the MSD to fire, all this while making sure that the dizzy is pointing in the right cyl. 

 

I hope that makes sense. 

 

Here is an article that helps explain this perhaps a little better. 

 

https://wiki.autosportlabs.com/MJLJ_V4_vehicle_installation_guide#Crank_timing_wheel_and_sensor_installation

 

Crank Pulley Design 

 

I consulted Tom at 02Again, and he is providing a hub,  2 pulleys (one for the accessories and one for A/C) and a trigger mount (which I will have to mod a bit).   The trick is to get it all packed in a relatively small space.    This is the unit built for an EDIS based system (this type of system has a different wheel design), which is incompatible with the Sniper EFI, but taking the parts from it will allow me to sandwich a fabricated "flying Magnet" style of  trigger wheel between the pulleys for the accessories and A/C . 

 

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I may have to modify this a bit because my trigger wheel may sit slightly closer or farther away from the front pulley, but all in all, I think I am about 80% of the way there. 

 

image.png.424d8d534c7a0c8f79b006db843a8b83.png 

 

Parts arrived

 

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Edit. 

 

Here is a video of AMT machine shop where I get my stuff done.   A great resource for those folks who live in Vancouver CA. 

 

Regards

 

 

And instagram

https://www.instagram.com/adamturbo1/

 

 

Ok so I finally programmed the timing curve into the Sniper.   The interesting thing is that the 123 doesn't change vac advance under 2000 RPM whereas the Sniper EFI will.  The crank wheel is done.  Pictures to come. 

 

 

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Here is the finished pulley and sensor holder. 

 

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How many magnets and pickups does it use?

Is the wheel with magnets the only method the system will work with?

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The wheel will have two magnets 180 degrees apart.    This is the only type of wheel that will work with the Sniper EFI.  If I went with an ITB setup with a Holley Dominator/Terminator ( or others) running it,   then it will accept a 30 or 60 tooth wheel. 

 

I like the EFI system, but there is a lot more functionality that they could have put into it just for the sake of turning on the capability.  The computing power required to use a 30 tooth wheel (like the majority of crank triggers) is minimal.  Also, the number of inputs and outputs on the 2bbl systems is reduced to essentially 1 if you use it for A/C and fan control, from 8 or more on the 4bbl version. 

 

 

 

 

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A quick update.  I got the wheel done,  I will try to install it this weekend.  I am interested to see if this sort of control makes any difference. 

 

Regards

 

P.S is the crank pulley bolt reverse thread?
 

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