6" Vac at Idle?

[My427stang]

Somehow my post didn't post

CV - The slot discussion doesn't apply to your Dualsync

Reset the cam and crank sensor at the value the instructions tell you, usually 50 degrees BTDC

Verify the programming "reference angle" in the distributor section matches that number

Set timing to 15 crank, 18 initial, 40 cruise, 35 total for nat aspirated

Fire it, let it idle, read timing with a light, if not 18 adjust inductive delay until it reads 18

[CV355]

Somehow my post didn't post

CV - The slot discussion doesn't apply to your Dualsync

Reset the cam and crank sensor at the value the instructions tell you, usually 50 degrees BTDC

Verify the programming "reference angle" in the distributor section matches that number

Set timing to 15 crank, 18 initial, 40 cruise, 35 total for nat aspirated

Fire it, let it idle, read timing with a light, if not 18 adjust inductive delay until it reads 18

Dumb question here, but if the static timing was already set/sync'd with the Holley DualSync, if I alter timing by rotating the distributor base, do I have to update it somewhere in the Sniper ECM?

[My427stang]

Good question

1. When you sync the dual sync (Put the engine at 50 BTDC and turn the distributor until both lights turn on and one barely shuts off) you are giving it a reference point to control timing from.  If it's right, it's right, but personally I would go back and make sure given what you are seeing.  There are two components of checking it....setting the distributor per the instructions and second is making sure the reference angle in the program matches the instructions. For example if 50 degrees is the reference angle, you set up the distributor, and then when you power up the program you make sure the same value, 50, is in the reference angle field.

2. You should never turn, or need to turn, the distributor after that, but you may need to adjust inside the program to make timing perfect.  Let's say your initial is set at 18 in the handheld, but you see 15 in the balancer with a timing light, the Inductive delay is like a thermostat that will correct it, it changes the delay in the computer to make the commanded timing match the actual timing, you don't turn the distributor.  I am not sure if the handheld will let you adjust inductive delay, but it is easily done on a laptop.  Also, you may not even need to do it, but it is worth checking with a light.  I did not need to do it on mine or the last one on the dyno, but since you are fighting potential timing issues it's a great idea to check it

After that, you are done forever with basic setup, you will just change timing values in the computer... initial, cruise and WOT.  I think it is FAR better to do timing changes on a laptop, but it takes a couple steps after you program the ECM to save to the SD card.  Easy after you do it once or twice.

Do you have the program on a laptop or doing it all by handheld?  The reason I ask is the Wizard is not as good as the free Sniper program.  However, if you have the ability to pull your global file off your SD card, I could manipulate it for you too and email it back

[CV355]

Good question

1. When you sync the dual sync (Put the engine at 50 BTDC and turn the distributor until both lights turn on and one barely shuts off) you are giving it a reference point to control timing from.  If it's right, it's right, but personally I would go back and make sure given what you are seeing.  There are two components of checking it....setting the distributor per the instructions and second is making sure the reference angle in the program matches the instructions. For example if 50 degrees is the reference angle, you set up the distributor, and then when you power up the program you make sure the same value, 50, is in the reference angle field.

2. You should never turn, or need to turn, the distributor after that, but you may need to adjust inside the program to make timing perfect.  Let's say your initial is set at 18 in the handheld, but you see 15 in the balancer with a timing light, the Inductive delay is like a thermostat that will correct it, it changes the delay in the computer to make the commanded timing match the actual timing, you don't turn the distributor.  I am not sure if the handheld will let you adjust inductive delay, but it is easily done on a laptop.  Also, you may not even need to do it, but it is worth checking with a light.  I did not need to do it on mine or the last one on the dyno, but since you are fighting potential timing issues it's a great idea to check it

After that, you are done forever with basic setup, you will just change timing values in the computer... initial, cruise and WOT.  I think it is FAR better to do timing changes on a laptop, but it takes a couple steps after you program the ECM to save to the SD card.  Easy after you do it once or twice.

Do you have the program on a laptop or doing it all by handheld?  The reason I ask is the Wizard is not as good as the free Sniper program.  However, if you have the ability to pull your global file off your SD card, I could manipulate it for you too and email it back

Sorry for the late reply, I didn't get a chance to actually work on the car until the weekend.

The reference angle on the DualSync is 50, which I verified.  I had to reset the static timing to 15 initial.  The engine fired right up and idled far nicer, but the vac dropped from 6" to 2".  No joke, the needle was resting on the tick mark around 0 just at idle.  We're still convinced that there is not a vacuum leak.  I did not get a chance to verify the timing with my timing light- that's a task for tonight and will adjust inductive delay as needed to sync the set and actuals.

I do have the ability to change initial, cruise, and WOT timing in the handheld.  The cruise and WOT figures looked fine.

Based on what I'm reading online, it sounds like I have a big discrepancy between actual and set timing.  It's acting like the timing is severely retarded when the Sniper thinks it is at 15 degrees advance.  If I should be seeing 10"-12" of vac at idle with this cam, I'm wondering just how far off the timing could be (assuming no leaks). 

[My427stang]

I recommend you download their Sniper program and get the laptop connector.  Otherwise, you could send me your file from the SDE card and I could try building you another to try

In the end though, you need to look at initial on the handheld (commanded) and what the timing light sees.  If they are different, we can fix in the program

Your initial should not be 15, initial should be 18 or 20, there is another field for crank timing.  I can set that if you send me your file.  My427stang    AT  yahoo   . com

It'll take me 10 minutes to try something for you o upload and we will name it something else.  You just need a computer that can read the card...worst case, an adapter is dirt cheap from Walmart (SD card to USB)

[CV355]

I recommend you download their Sniper program and get the laptop connector.  Otherwise, you could send me your file from the SDE card and I could try building you another to try

In the end though, you need to look at initial on the handheld (commanded) and what the timing light sees.  If they are different, we can fix in the program

Your initial should not be 15, initial should be 18 or 20, there is another field for crank timing.  I can set that if you send me your file.  My427stang    AT  yahoo   . com

It'll take me 10 minutes to try something for you o upload and we will name it something else.  You just need a computer that can read the card...worst case, an adapter is dirt cheap from Walmart (SD card to USB)

I'll give that a shot with my laptop tonight.  If I can't figure it out, I'll send the file over to you.  Really, really appreciate your advice on this.

[My427stang]

Happy to help, it keeps me thinking between engines too.

One thing I noticed is when you get on the laptop program. 

When you use the wizard, the timing comes in too fast and not enough.  Real odd too, like 30 degrees all in by 2100

The way around can be done 2 ways

1 - Start with one of their packaged global files for a big block they tend to be slower curves
2 - Under timing, set your initial, cruise and WOT under "simple", then open the 2D table option and copy and paste cells to slow the curve down.
3 - Of course there is still the starting timing to set, that's a completely different field, and you want that nice and low to let it crank easy, 13-15 should work