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Holley sniper timing question

Loulang

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I have a 1966 Dodge charger with a 383 bored .30 over with Keith Black pistons edelbrock aluminum heads all roller motor with a mild cam and the holly sniper 1 system. I’m just wondering what I should set my timing and my WOT timing at. Really wondering if anybody has this type of set up and what they did just to get some base numbers for now. Thanks for any input much appreciated
 
The first thing is to get the base timing distributor position correct.
I'm guessing they have a selection which you make which fixes the timing so you can set the distributor. (MSD asks for -25)

I don't have the Sniper (MSD atomic) but I would suggest trying -15 initial and -35 total to start with.
If they have unported vacuum advance select that (mine likes a bunch of advance at idle so unported makes it advance further at idle).
After you get it running and drive it a bit try watching the timing at idle and IAC position.
Just be careful and don't get into an accident.

Also see if you can watch the timing while cruising see how high it goes mine gets capped at -42 but I think it would benefit from an even higher value.
Unfortunately -42 is the maximum.
 
Why should it be any different than timing a carb'd engine ! 12* initial, 38* total - all in by 2000 rpm. Adjust as necessary
 
The first thing is to get the base timing distributor position correct.
I'm guessing they have a selection which you make which fixes the timing so you can set the distributor. (MSD asks for -25)

I don't have the Sniper (MSD atomic) but I would suggest trying -15 initial and -35 total to start with.
If they have unported vacuum advance select that (mine likes a bunch of advance at idle so unported makes it advance further at idle).
After you get it running and drive it a bit try watching the timing at idle and IAC position.
Just be careful and don't get into an accident.

Also see if you can watch the timing while cruising see how high it goes mine gets capped at -42 but I think it would benefit from an even higher value.
Unfortunately -42 is the maximum.
Thanks for the advice I live in the boonies so I have plenty of wide open road for testing
 
Right now I’m at 15 initial and 36 WOT
That's pretty close to ideal. However, its not WOT you should be concerned with, its getting your "total" in by 2000 RPM

Are you using the Sniper to control timing or the distributor ??
 
Yes I am and it switches around that rpm
 
So I pretty much agree with the above comment. EFI likes quick advance it really lets you tailer the low end response.
Here's how mine is set on the MSD. The idle speed is not set at 1100 it's set to 675. But the advance curve starts at 1100.
1712667535836.png
 
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Give it as much initial as it will handle. The essentially bone stock, Sniper-equipped 383 in my old '68 Coronet was fine with 18-20 initial. No need to weld T-slots or anything, just program it in. You can go cell by cell if you want to get that far into it. Being able to control the timing to such a finite degree is really the beauty of the whole system.

Here's a video about how to create a timing table in the software. You do have a laptop hooked up to the ECU, right?

 
Give it as much initial as it will handle. The essentially bone stock, Sniper-equipped 383 in my old '68 Coronet was fine with 18-20 initial. No need to weld T-slots or anything, just program it in. You can go cell by cell if you want to get that far into it. Being able to control the timing to such a finite degree is really the beauty of the whole system.

Here's a video about how to create a timing table in the software. You do have a laptop hooked up to the ECU, right?


yes I do I am computer illiterate but I am slowly trying to learn lol
 
Creating custom timing and fuel tables is the best way to get a thorough understanding of the software. Once I did that, everything became clear. Post #3 by gkent is correct in that these concepts are the same as a carbureted engine but the graphical interface really helps you see it as a whole.

I'd also suggest joining the Holley EFI forums, you'll get much more specific answers there. You can upload your config files and subsequent data logs for help if you're having trouble with something or just want to know if you're on the right track.

Sniper forum
 
Are you controlling timing with the EFI (Hyperspark distributor etc), and are you using the tuning software on a PC? If so, I have a spreadsheet that you can use to input all your desired timing values at every point in the RPM curve and then copy/paste into your Holley EFI software.
PM me your email address and I will send you the file.
*Note--you do need to know what you're doing when manually manipulating your GCFs...I make no guarantees or promises!
The file I have has worked wonders for my crew though. Wayyy better than the "wizard" or handheld interface timing setup values.
You will be able to adjust the timing to what your engine likes from idle to WOT, your various cruise speeds and everything in between.
 
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The image below is of a base fuel table but your timing will obviously be inferred from it. The blocked out areas are not set in stone nor will they be the same for every engine but it's a good starting point. There will be overlap between most areas too so you will have to drive the car, see what it wants and make adjustments as needed.

Be aware that as the ECU learns, the 'learn table' will fill up with values. If the learn table values are consistently larger in a particular area (+/- say a value of 15) then you need to make adjustments to your base tables to get the compensation percentages in line. When building your air/fuel ratio table it's probably a good idea to use these areas as a guide as well, it's all related. If/when the car is running good, the learn table values will be single digits and the closer to 0 the better. The table will never be all zeros though as there will always be some level of compensation due to weather, temps, etc.

Applying these concepts through the software is where 'the magic happens' and is precisely why you want to create your own fuel and timing tables. Using someone else's 'known good' tune is fine and will provide a place to start but it may not be a perfect fit for your particular application. I maintain that creating your own tables is a worthwhile exercise when learning how to navigate the software. Active involvement with the tuning process is what separates the OK running cars from the razor sharp ones. Custom tailoring everything to your specific application is what makes the investment worthwhile. A lot of guys don't go through that process and probably don't even know it's something they could be doing.

1712708989039.png


What I will say is that before you start doing anything make sure the X/Y axes 'make sense' and are the same for both the fuel and timing.
 
Using someone else's 'known good' tune is fine and will provide a place to start but it may not be a perfect fit for your particular application.
I'm not sure if this was in reference to my post, but the spreadsheet file I mentioned is not my nor anyone else's tune but rather a customizable Excel sheet with the proper formulas that can calculate and set the table values according to the data you enter.
You will enter your known and/or desired values at the left, and the program will fill in the table and be close to ideal BUT you will have to verify and customize the table values according to your particular engine build and vacuum/kPa readings under the various driving conditions...

This a rudimentary partial screenshot of what it looks like:
1712715389166.png
 
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Guess I misunderstood the Excel file idea but unless I'm missing something, entering timing values in Excel and then copy/pasting them into the Holley software seems like an unnecessary step since that's exactly what the Holley software does when you create a new table. You have to input the data at some point so might as well just do it in the Holley program. That's how I did it and it worked fine plus it helped me learn how to use the software.

Additionally, the Holley software will smooth out the table values since you don't want clearly defined steps in between the data points or it won't run right. When viewed as a graph, the representation should look like an undulating wave, not a sheer, jagged cliff.
 
My head hurts already lol
It probably sounds like a bunch of gobbledygook when you are just reading about it but once you get into it this will all make sense.

As long as you have a grasp on the traditional tuning process, the program itself is pretty basic. If you can perform basic computer functions like “Save as” or enter numbers into blank fields you will be fine.
 
I should of did more research on Holley sniper tuners we’re I live. Before I pulled the trigger. There is not one within 250 miles FM LOL. Wish there was someone in Northern Michigan by the Mackinaw bridge that I could visit. Gonna do some more research
 
I hate to push the Holley forums again but there are at least two guys on there that do remote tuning so there's no real need to find someone local. There are tons of videos on You Tube as well. YT actually helped me when I was learning about EFI.

The wiring is the most important part of the whole thing. Any time these EFI threads come up I repeat my mantra about wiring - it has to be good or you will have problems. Read and understand the instructions - when they say wire something directly to the battery, do it. If you call the tech line for help the first thing they ask is if you wired the ECU to the battery. So no running the main power wire to the coil + or wiper motor, no quick splices or wires twisted together with electrical tape, don't piggy-back stuff off a 53+ year old fuse box, make sure the alternator puts out good voltage and on and on.

Honestly, if you're into the tuning without having any major startup or electrical issues you're 3/4 of the way there. Even if you do little to no hands on tuning the car will run and it will learn, it's up to the individual how far they want to go with it. I like the process but some guys just want to let the ECU do it's thing and never lift a finger. Takes all kinds.
 
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