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Discussion Starter #1
Finally pulled the trigger on going EFI after 2 yrs on thinking about it.... This is a 615"BBC with (2 dry systems) with Holley Dominator ECU. Using Holley smart coils, using old MSD crank trigger wheel, Hall Effect sensor, & "EFI CONNECTION unit" for cam sync. As seen in the photos right now we are setting up base timing around 28*.
Hall Effect is aligned the magnet. Question is with the cam sync.....When dropping the shaft in, should the sensor at the base (center of wire harness plug) be aligned with the center of the "overhang" of the wheel as seen in the pic?
Also.......not clear on digital rising or falling.
Thanks for any help with this set up procedure ...Ray


 

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Ray,

The timing mark 30* has no impact in this configuration. You need to set the crank trigger pickup to align a magnet @ 60* BTDC. Rotate back 30* and align a magnet there. Once that is set, rotate to 195* BTDC and set the cam sync on the edge where the metal is disappearing (digital falling on ECU)
 

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Yeah, what Dennis said! Forget all you learned about with setting up a "normal" distributor and rotor-phasing, that all goes-out the window now. :)
 

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Just take a bit and make sure you understand how this all works. It seems confusing at first. Everything everyone said up top, is true, but if the most timing you run will be 28, I'd set up the reference angle to 40 degrees instead of 60. This would mean you'll want the cam sync around 175 degrees BTDC on 1.
The "reference angle" is when the crank trigger magnet hits the crank sensor. This tells the ECU "I'm at the reference angle". It can then calculate when to fire the coils after that (at 28, 10 degrees, whatever you program in with the laptop). The way the MSD used to work, is it would fire when the magnets hit the sensor, the EFI, this just tells it where it is.

The cam position is a "flag" for the ECU to tell it where cylinder #1 is. It doesn't have to be precise, but within a certain 90 degree angle.

The Holley software help section has an area telling you how to set this up.
 

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Discussion Starter #7 (Edited)
All I know Mike is what I "use to know"....lol.....NOW forgetting that and learning a new "language" is not so easy for me. If there was a VIDEO on the sequence of events on the set up (a example) that would be very helpful for us newbie's....lol

Thanks 64duce....going to try your reply now......

Doug...28* will be our base timing once I learn this EFI and turning on the nos. (28* = reference angle of 40 degrees.....ok) Since we will be breaking this in on a chassis dyno, lets say I want the time more around 34* base. What reference angle are you looking at then? just trying to understand this all.

Thanks All
 

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All I know Mike is what I "use to know"....lol.....NOW forgetting that and learning a new "language" is not so easy for me. If there was a VIDEO on the sequence of events on the set up (a example) that would be very helpful for us newbie's....lol

Thanks 64duce....going to try your reply now......

Doug...28* will be our base timing once I learn this EFI and turning on the nos. (28* = reference angle of 40 degrees.....ok) Since we will be breaking this in on a chassis dyno, lets say I want the time more around 34* base. What reference angle are you looking at then? just trying to understand this all.

Thanks All
12 to 15* ahead of your maximum timing is plenty. Some don't have the flexibility to move the pickup. That'll sometimes dictate what you have to run. I'm working on a video that explains this exact thing. It'll be on youtube shortly. You should be done before me tho...LOL
 

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The reference angle should be about 10 more than the MOST timing you'll run. Just time for the ecu to go "here is where we are at (ref angle), then command the timing". 10 is more than you need, but makes it a safe number.

So ref should be (general rule of thumb) = most timing +10 degrees
 

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Discussion Starter #10 (Edited)
That helps a lot Dennis.. again, just so im clear.....If say 28* is my "BASE" timing in the future, setting it up like Doug suggested is fine.
Also....we will be pulling timing down into around 8*-10* range total, when both guns are ON...........still ok here?
40* on the balancer and Hall effect & a magnet are perfectly aligned....


NOW rotate to 175* and drop in cam sync with metal edge leaving....?


Am I understanding you guys properly?......Ray
 

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Ray, just find somewhere your crank sensor will be right at a magnet on the trigger wheel which is at least 10* more than you'll ever need.

If you think 34* is the most you'll ever run, get a magnet to line up with your sensor at 44* on your balancer.

Since 44* is a strange # (to me) and 50* or 60* is much easier to remember, that is where I would set it.

When you decide where you will line up a magnet and the sensor, that number needs to be entered into the ECM so it knows what you're doing. Also, when making that type of change in the ECM, the power needs to be cycled off for the change to take effect. The next time you turn the ignition on the change will be seen in the ECM.

Now, when all that is done, you will need to determine where to get the cam sync to line-up. There is a formula in the Help Section of the Holley software so you can determine the correct location. I think Danny also put a link to it above.

I honestly always forget how I set mine up. It is setup for Digital Falling, that I know. Now, whether I have the wheel just about to block the sensor, or just about to leave the sensor, that is what I always forget! I wrote it inside the cap of the cam sync though, with the correct timing for the balancer, so I can get it right. Lemme go look for you.
 

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That helps a lot Dennis.. again, just so im clear.....If say 28* is my "BASE" timing in the future, setting it up like Doug suggested is fine.
Also....we will be pulling timing down into around 8*-10* range total, when both guns are ON...........still ok here?
40* on the balancer and Hall effect & a magnet are perfectly aligned....


NOW rotate to 175* and drop in cam sync with metal edge leaving....?


Am I understanding you guys properly?......Ray
Short answer is yes, correct. That will get things mechanically close to start.
 

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You can do something like this too. Jesel sells the washer with the tang on it and you can just make the holder and use a stock GM sensor.... Very easy to position

 

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Discussion Starter #17
Dragzilla......another option when using a front drive distributor. I "had" something similar when running my ICT w/7531 box.

Great Mike...AND thanks for spending the time pulling your car apart. A pic is worth a 1000 words sometimes.
Now I get it. Out with the old & in with the "reference angles".......lol ...............Starting to see the light.
 

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This thread is great and should be made a sticky. I am going to be going thru this in a couple of months and have had the same questions. I will print this out for future reference.
Dennis, if you make a video you should post up a link, That would be very helpful.
Tom
 

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Dragzilla......another option when using a front drive distributor. I "had" something similar when running my ICT w/7531 box.

Great Mike...AND thanks for spending the time pulling your car apart. A pic is worth a 1000 words sometimes.
Now I get it. Out with the old & in with the "reference angles".......lol ...............Starting to see the light.
Ray, I'd love to say I pulled it apart just for the photo ops, but a few weeks ago it ate an intake valve........... So it just happens to be apart at the right time to take some pictures for you! :)
 

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I am no expert but I'm in the middle of doing the same set up on a sbc myself. The picture of 598 nos 's cam sync shows the flap covering the sensor on the cam sync, but isn't the side ( the vertical edge opposite ) what the sensor reads and not that flap? So that edge should be ready to exit the sensor when properly setup for digital falling? That's how I set mine up so if I'm wrong I guess I will be climbing under my windshield to change it. Gotta love fourth gens!
 
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