Anyone have a base timing table they could share?

[Pentroof]

I’m going to start over with my Holley Sniper. Since I now have the software loaded and a USB cable, I can load a proper table.

I can get there with a bunch of editing and smoothing, but it would be great if I started with something in the ball park and then used the data logging and real time tuning to dial it in. The table generated by the ECU isn't even worth editing. May as well fill it out from scratch.

1970 F100, stock 390 bottom, Edelbrock heads, PI intake, FPA tri-Y headers, 3.25 rear with a C6
Pretty mild hydraulic roller: 215/220 @.050, .500 lift with 113 lobe sep at 110 ICL

I plan on editing from the driver's seat with my daughter driving. Closest thing I have to a dyno.

If you've got something remotely appropriate, I'd appreciate it. You can email me directly or even post an image here for others to comment on.

(3 letter first name seen below)@snowmobility.com

Thanks,
Jim

[jayb]

This was the one I used on my recent dyno mule.  Might not be a perfect match but hopefully it will get you started.  Idle advance is probably a little high...

[My427stang]

Can you post what the Sniper has now?

I am on the wrong computer to post mine, but happy to, just want to make sure I am posting it in a  format you can use.

Also, you can look up Megasquirt Timing Table generator, there are couple of websites that do it for you, not sure if the format works with the Sniper, but another option

Looking forward to seeing Sniper format, hopefully you have option to post it

[Pentroof]

Thanks for your post Jay.

This may not be easy to read...
The only transitional editing the ECU made is what you see in green. The other three colors represent my 3 data inputs inputs for idle, cruise and WOT...(being a bit conservative to begin with). The ECU determines the extent of the zones (rpm, pressure), I assume by the other initial settings such as C.I.D, type of cam, etc.

The software allows all kinds of editing. I can highlight regions and move that whole region up or down incrementally, smooth everything or smooth just a highlighted area. Or, just enter data cell by cell. Uploading and downloading is simple as well. I don't think it differs all that much from other software tools out there.

[FElony]

I have absolutely no idea what any of this stuff means, but I did see "Launch Retard", and I assumed it was my cue to post something.

[66FAIRLANE]

I did see "Launch Retard", and I assumed it was my cue to post something.

LOL!!

Which distributor are you using? Anything but the Holley one apparently can prove problematic. I would let the distributor take care of the timing until I had the fuel maps pretty much sorted. Then go for the timing. There is excellent Sniper advice on the Holley Sniper forum here
https://forums.holley.com/forumdisplay.php?82-Sniper-EFI&s=cdf180171ff2aea4346e1a2a3b9306be

[Pentroof]

Yeah, I've lurked a bit on the Sniper forums and picked up some good info. The problem is all of the answers come from the same forum moderator and I'm not convinced he's got a complete handle on everything.

I'm not turning back now. I've gutted my Duraspark to lock it out and the rotor has been phased (using a tip posted here to add a groove to move the reluctor wheel).

[Pentroof]

This is the base table I came up with, using Jay's above table as directional guidance. There are a number of options to tweek the advance in dynamic conditions, but I think this is a good starting point.

THOUGHTS?

[My427stang]

Does the Sniper need that many cells?

Most of the systems I see use far fewer cells, which honestly only help in data entry, but 31x31 seems excessive.  Most are 12 x 12 (load vs rpm) or 24 x 24

Regardless, that current setup is hardly a curve.  It stays at 16 until 2250 then just advances to 26 then 36, no wonder it pings, also down on low rpm power. 

IMHO, even just a closer to linear growth on all the low load lines through 2800 would be better with the same initial and total.  There is much more you can do with low load cruise advance (like vacuum advance) but, even just changing all 1st 10 columns to should make it more responsive part throttle and avoid the immediate advance at 2250 and up.  It would also give you some data to try something different next

16  16  18  20  20  22  24  27  30  36

You could adjust from there, but I can see at 2250 it gets a bunch of advance then again at 2500, that's very aggressive.  My quick line isn't fancy, but just working back from full advance at 3000 to a curve you are happy with could make a heck of difference, then you could adjust low load to exceed 36 for mileage after you get that goofy curve under control

[My427stang]

My last was a WAG before you posted

Yours is worth trying, but I think you'll find you hit total too soon in most cases

[andyf]

The first column should have more timing than the second column so the idle speed self corrects if it drifts too low. When the first column has less advance the engine can hunt or surge back and forth.

[Pentroof]

The first column should have more timing than the second column so the idle speed self corrects if it drifts too low. When the first column has less advance the engine can hunt or surge back and forth.

That's some great info. Makes sense. Maybe even drop my 750 idle timing to 15 and bump the 500 up to 18?

[andyf]

Maybe, but you also want to remember that you have a starter cranking speed that needs a spark. You don't want to be too advanced when cranking the engine.

Nice thing about EFI is that you can throw away all that MSD stuff. Start retard box, gone, high speed retard, gone, advance weights, gone, vacuum can, gone, rev limiter pills, gone. MSD is going to be hurting in a few years after more people switch to EFI!

[Pentroof]

Currently, the starting timing is retarded with the CD box below 400 rpm. I'm probably going to change that and move that control to the Holley ECU so everything is within the same config file and available on the laptop screen.