Holley Sniper 440 timing question

My first EFI on a new stock 440 build with a mild cam. Holley Sniper, Hyperspark, ignition, coil the works. We have put about 75 miles on it. I was hoping someone here has plowed the base timing table ground. Settings are for start; idle; cruise; and WOT. Any successful experience would help. Thanks Phish

Just use a normal timing curve. Maybe 15 at idle, 35 at WOT, 42 at cruise. Fill those blocks in and smooth the table. Are you using the handheld to enter numbers or have you hooked up a laptop? If you use the handheld you end up with a really blocky table. Best way is to hook up a laptop or pull the SD card and program it on your desktop computer.

I watched a Youtube of that. We used the handheld to get it going. May bring it to a chassis dyno as well as smoothing the table. Thanks

Not to hijack but does the Holley sniper work well with a dual plane intake? I'm running a Eddy RPM on a 470. I've heard both ways. Let us know what you think of the system. Thanks

No problems with a dual plane intake. I think every one of the aftermarket EFI systems I have installed have been on Dual plane intakes, Never had any issues.

Here is a video of the Sniper setup in my Coronet. This is a low deck pump gas 512 engine with an Edelbrock RPM intake. It seems to work just fine. https://www.youtube.com/watch?v=xG3-_YJGdZ8

Page 50 of the Sniper xflow manual says the idle, cruise and W.F.O. timing will "be blended together automatically". If you hook it up to a laptop, and have someone available with the know how, you may be able to improve upon it for your application. It also says that changing one of the values will raise or lower the curve in that area. I figured they took engine vacuum and r.p.m. into consideration when making the "curve"

The Holley software does a very poor job of building a timing table. I highly recommend using a computer to smooth the timing table. A laptop is a nice way to do it since you can sit in the car and make changes as the engine runs, but it isn't required. The SD card can be popped out of the handheld and inserted into a desktop computer which has the Holley software. After the program is changed the SD card is put back in the handheld and the new program is uploaded to the Sniper.

Imo, one of the best features of that system is being able to make your own timing and fuel maps on the computer, and how easy it is to do.

Thanks guys!

On my sons car we did just as Andy said. Put the base idle and cruise along with WOT timing and then pull the card and put it in the labtop and fill the blocks to make a great timing curve. When we first had it running before we filled in the full timing curve and drove it you could feel the timing jump from idle to cruise but we pulled the card and put it in the labtop and figured out how to make a good smooth curve filling in all the blocks. And then you can always modify more as my son is always tweaking his to get it perfect. Course we will be changing his a lot since its getting supercharged this year. Ron

Is 42 at cruise correct? Or a typo. Thanks

I am not Andy, but yes 42

This is the small table on my 512 Mine uses the 56 & up KPA

42 at cruise seems like a good place to start for your engine. Just think of it as the vacuum advance.

My dash reads everything, this is cruising down the Freeway

How many inches of vacuum or pounds of manifold pressure is 64.1 KPA?

Depends on the elevation but at sea level it would be around 12 inches of vacuum. At sea level kPa is a 0 to 100 scale while vacuum is 0 to 30 in hg or 0 to 15 psi.

Not sure what your real question was. Do you think 42 is too high or too low? It is fairly common to run more than 42 at cruise but I suggested 42 as a starting point. With a Sniper you can drive down the freeway and adjust the timing to find out what it really wants. Your combination might want 45 or 47 or 50 degrees of total timing while cruising down the freeway. All depends on the engine and the car.

I will be back with the car Monday. A local shop has a chassis dyno with associated Sniper software etc that I MAY use. I will try your base numbers and drive around some and may smooth the chart myself if I can figure out how to get a copy. (I HAD peeps). Or bring it to the dyno shop ( which has mixed reviews). Not trying to rotate the earth, just a daily driver. FYI I had cruise set at 20 degrees so don't throw me under the bus. LOL Told you it was my first one. So far I love it for cold start etc. Stephen AKA Jake

PS Ignore camera date, need to get Granddaughter to fix that
UPDATE, I have the software downloaded!!!!!!!

Just shy of 19.

http://www.kylesconverter.com/pressure/kilopascals-to-inches-of-mercury

Kevin

That conversion is not correct
This is what a automotive Vacuum gauge would read

Default MAP kPa to inHg (vacuum gauge) to PSIG

105 kPa = +1.48 inHg = +0.72 psig
104 kPa = +1.18 inHg = +0.58 psig
103 kPa = +0.89 inHg = +0.43 psig
102 kPa = +0.59 inHg = +0.29 psig
101 kPa = +0.30 inHg = +0.14 psig
100 kPa = -0.0 inHg = -0.00 psig
99 kPa = -0.30 inHg = -0.14 psig
98 kPa = -0.59 inHg = -0.29 psig
97 kPa = -0.89 inHg = -0.43 psig
96 kPa = -1.18 inHg = -0.58 psig
95 kPa = -1.48 inHg = -0.72 psig
94 kPa = -1.78 inHg = -0.87 psig
93 kPa = -2.07 inHg = -1.01 psig
92 kPa = -2.37 inHg = -1.16 psig
91 kPa = -2.66 inHg = -1.30 psig
90 kPa = -2.96 inHg = -1.45 psig
89 kPa = -3.26 inHg = -1.59 psig
88 kPa = -3.55 inHg = -1.74 psig
87 kPa = -3.85 inHg = -1.88 psig
86 kPa = -4.14 inHg = -2.03 psig
85 kPa = -4.44 inHg = -2.17 psig
84 kPa = -4.73 inHg = -2.32 psig
83 kPa = -5.03 inHg = -2.46 psig
82 kPa = -5.33 inHg = -2.61 psig
81 kPa = -5.62 inHg = -2.75 psig
80 kPa = -5.92 inHg = -2.90 psig
79 kPa = -6.22 inHg = -3.04 psig
78 kPa = -6.51 inHg = -3.19 psig
77 kPa = -6.81 inHg = -3.33 psig
76 kPa = -7.11 inHg = -3.48 psig
75 kPa = -7.40 inHg = -3.62 psig
74 kPa = -7.70 inHg = -3.77 psig
73 kPa = -7.99 inHg = -3.91 psig
72 kPa = -8.29 inHg = -4.06 psig
71 kPa = -8.59 inHg = -4.20 psig
70 kPa = -8.88 inHg = -4.35 psig
69 kPa = -9.18 inHg = -4.49 psig
68 kPa = -9.47 inHg = -4.64 psig
67 kPa = -9.77 inHg = -4.78 psig
66 kPa = -10.07 inHg = -4.93 psig
65 kPa = -10.36 inHg = -5.07 psig
64 kPa = -10.66 inHg = -5.22 psig
63 kPa = -10.96 inHg = -5.36 psig
62 kPa = -11.25 inHg = -5.51 psig
61 kPa = -11.55 inHg = -5.65 psig
60 kPa = -11.84 inHg = -5.80 psig
59 kPa = -12.14 inHg = -5.94 psig
58 kPa = -12.44 inHg = -6.09 psig
57 kPa = -12.73 inHg = -6.23 psig
56 kPa = -13.03 inHg = -6.38 psig
55 kPa = -13.32 inHg = -6.52 psig
54 kPa = -13.62 inHg = -6.67 psig
53 kPa = -13.92 inHg = -6.81 psig
52 kPa = -14.21 inHg = -6.96 psig
51 kPa = -14.51 inHg = -7.10 psig
50 kPa = -14.80 inHg = -7.25 psig
49 kPa = -15.10 inHg = -7.39 psig
48 kPa = -15.40 inHg = -7.54 psig
47 kPa = -15.70 inHg = -7.68 psig
46 kPa = -15.99 inHg = -7.83 psig
45 kPa = -16.28 inHg = -7.97 psig
44 kPa = -16.58 inHg = -8.12 psig
43 kPa = -16.88 inHg = -8.26 psig
42 kPa = -17.17 inHg = -8.41 psig
41 kPa = -17.47 inHg = -8.55 psig
40 kPa = -17.77 inHg = -8.70 psig
39 kPa = -18.06 inHg = -8.84 psig
38 kPa = -18.36 inHg = -8.99 psig
37 kPa = -18.65 inHg = -9.13 psig
36 kPa = -18.95 inHg = -9.28 psig
35 kPa = -19.25 inHg = -9.42 psig
34 kPa = -19.54 inHg = -9.57 psig
33 kPa = -19.84 inHg = -9.71 psig
32 kPa = -20.13 inHg = -9.86 psig
31 kPa = -20.43 inHg = -10.00 psig
30 kPa = -20.73 inHg = -10.15 psig
29 kPa = -21.02 inHg = -10.29 psig
28 kPa = -21.32 inHg = -10.44 psig
27 kPa = -21.61 inHg = -10.58 psig
26 kPa = -21.91 inHg = -10.73 psig
25 kPa = -22.21 inHg = -10.87 psig
24 kPa = -22.50 inHg = -11.02 psig
23 kPa = -22.80 inHg = -11.16 psig
22 kPa = -23.09 inHg = -11.31 psig
21 kPa = -23.39 inHg = -11.45 psig
20 kPa = -23.69 inHg = -11.60 psig
19 kPa = -23.98 inHg = -11.74 psig
18 kPa = -24.28 inHg = -11.89 psig
17 kPa = -24.58 inHg = -12.03 psig
16 kPa = -24.87 inHg = -12.18 psig
15 kPa = -25.17 inHg = -12.32 psig
14 kPa = -25.46 inHg = -12.47 psig
13 kPa = -25.76 inHg = -12.61 psig
12 kPa = -26.06 inHg = -12.76 psig
11 kPa = -26.35 inHg = -12.90 psig
10 kPa = -26.65 inHg = -13.05 psig
9 kPa = -26.94 inHg = -13.19 psig
8 kPa = -27.24 inHg = -13.34 psig
7 kPa = -27.54 inHg = -13.48 psig
6 kPa = -27.83 inHg = -13.63 psig
5 kPa = -28.13 inHg = -13.77 psig
4 kPa = -28.42 inHg = -13.92 psig
3 kPa = -28.72 inHg = -14.06 psig
2 kPa = -29.02 inHg = -14.21 psig
1 kPa = -29.31 inHg = -14.35 psig
0 kPa = -29.61 inHg = -14.50 psig

So I have got a lot of info from this thread. Do I need a Holley special cable to hook to the computer or a regular USB. Thanks

Where does the calculator go wrong? I have an app on my phone that comes up with the same answer.

18.92871914879627 inches of mercury.

Not sure, what I posted is off the Holley forum, it also matches my vacuum gauge.

That is the conversion to pressure. Cab asked about vacuum. 64 kPa is 18 inches of pressure or 12 inches of vacuum.

The Holley cable is CAN on one end and USB on the other end. I don't think you can buy that cable from anyone other than Holley but I might be wrong. CAN to USB is an odd duck, you aren't going to find it in a local Radio Shack but you might be able to order one online. I wouldn't risk it myself, just order the Holley cable even though it is expensive.

So I have the car running 10 start, 15 idle, 42 cruise and 35 WOT. Holley cable on the way and free software is on this laptop. When cable gets here hook it all up and start driving. NOW how do I "know" what it likes. For instance cruise as we adjust timing what do we look for,max Kpa reading? Thanks

These are dumb questions but all I know is SS/AH holley 600 vac secondary wide open for 8 seconds. Phish

A large detail I missed...

Thanks.

Kevin

Originally Posted by Danny Cabral
Use conversion factor of .2953/29.53 @ 32°F or .2961/29.61 @ 60°F air temperature.
Convert MAP kPa to inHg (vacuum gauge): MAP kPa x .2961 − 29.61 = inHg Vacuum Gauge

Convert MAP kPa to psig (gauge): MAP kPa x .145 − 14.5 (slightly above sea level) = PSIG
Convert MAP kPa to psia (absolute with atmosphere): MAP kPa x .145 = PSIA

With PSIG, negative numbers are vacuum, and positive numbers are pressure.
With PSIA, all numbers are positive. The Holley EFI software uses kPa & PSIG.

The Holley EFI software uses kPa or PSIG (not PSIA). Here's an excellent pressure conversion calculator:

I skip all the math and just do it in my head. kPa is roughly a 0 to 100 scale. So 50 kPa is in the middle of the scale. Vacuum is 0 to 30 inches of hg. Middle of the scale is 15 inches of vacuum. So 50 kPa is 15 inches of vacuum. Once you know that you can figure out the rest.

First thing to do is to get the car running and warm up the engine so you can work on the hot idle. Once you have the engine warm you adjust the idle settings just like you would a carb. Slowly drop the idle speed and see how it does. Play with the ignition timing to see what it likes. Adjust the AFR to see what it likes. Adjust the throttle position to get the IAC into the correct location. It is exactly how you tune a carb engine except you don't have to change jets and mess with the distributor springs. You can do it all on the laptop by changing the values in the tables.

There are a bunch of Holley tuning videos on youtube so I'd suggest starting there if this is all new to you. It is like anything else. Once you know how to do it it is very simple but when you don't know how to do it it is intimidating. Watching a few videos will get you comfortable with the process of paging thru the menu and opening up the tables and stuff like that.

You aim for minimum kPa when tuning. kPa is pressure. You want to aim for maximum vacuum which is the opposite of pressure. Your idle pressure should be around 50 kPa on a well tuned engine with a modest performance cam in it. That is 15 inches of vacuum. A race car might idle at 70 kPa while a car with a stock cam will idle at 40 kPa. When you adjust the timing and/or the idle AFR you shoot for lower kPa. The other way to do it is to watch the IAC position. The IAC controls the idle air flow so what you want to do observe what is happening to the IAC position as you adjust the timing and the AFR.

On the IAC setting I like to get it at about 5 to 15 steps at idle with a warmed up eng in park. The steps will pick up a little in gear with an auto. You can adjust the throttle to set the IAC but you have to have timing at idle and all other settings set. If the IAC is at say 45 steps at warm idle you can turn the throttle blade open a bit more and watch the IAC steps come down. You don't want the IAC steps at 0 with a warm eng in park because then it may not catch the idle fast enough when you let off the gas since it can go to 0 steps. Once you set the throttle and the IAC then when you shut the eng off and restart it the controller will see the new TBS volts as idle since the TBS volts will change if you change throttle blade opening. Ron

My cable gets here Tuesday. Great info guys...

BINGO

I saved the ECU file to the SD card and it shows 4150_4_ZAA.sniper. The laptop sees it but not the V5 software, it will not recognize that file type. Guess I need to download the instructions. Phish

Your statement about V5 software leads me to believe that you loaded the wrong software on your computer. Delete the V5 software and load the Sniper software. You do not want to mix and match those two. Bad things will happen. I destroyed a $2000 Holley Dominator ECU by accidentally loading the wrong software on to it.

This is a brand new engine so 1. I think your right on software, I am clueless. 2. I will (use the Wizard) and take it somewhere that has done this, probably not local. Stephen

I downloaded the Sniper software from Holley and was able to view the file I saved from the SD card out of the car. The spark graph was very "boxy" so I hit the smooth key about 3 times and saved it. Is that it? Stick it back in the car and run it? Thanks

Now you're rolling. Yes, you can smooth the timing map by hitting the smooth button a few times and then drive it. Maybe snap a picture of what the timing map looks like and post it on here. There is also a graph function on that table so you can view it graphically. There is a little rotation bar at the bottom of the picture so you can rotate the graph to look at it. What you want is a nice smooth graph without any sharp peaks or ledges or cliffs.

Here is 15 idle, 42 cruise and 34 WOT smoothed about 3 times. Still pings but runs a LOT better. 1st pic is graph and 2nd is numbers. Then I found a sample stock cam in the Holley sniper files and went to simple mode and put in our base numbers same as above. It recalculated and made the 3rd pic chart and 4th sheet numbers. I have not run it with that as I hate to experiment with a new engine. Just WAGing. Also seems to be sensitive to set IAC at 5 to 15????? After idle a while it goes to 0... Thanks for advice Phish

The bottom ignition timing looks like it is for a boosted engine. The timing drops off at the top of the page which is probably for boost. Look at the kPa number and see what it is. Anything over 100 kPa is boost.

Adjust the throttle position (idle speed screw) at idle with the engine warm. At least 140 or 150 degrees on the coolant sensor. You adjust the throttle position until the IAC is around 10. If this is an auto do it in park. If you set it warm and it still gradually goes to zero then you have some sort of vacuum leak somewhere in the system.

Make sure that you have verified that the timing on the computer matches the timing at the dampener with a timing light.

Yes that is a very good point. Check it at idle as well as at a higher speed. There is also a static timing setting on the Sniper which is useful. You can just touch the button on the menu and then type in the timing that you want the Sniper to hold at while you check it.

OK Sniper 1 Phish 0. Took it for a drive after smoothing the file a couple more clicks. After it warms, we have IAC at 10 and it is holding now. I notice after driving and letting off gas to coast it goes to IAC 0. That ok?

BUT I decided to check the kickdown, went WOT cruising in high, it downshifted, pulled nicely with small pings and the TPS went red at 96 and stayed red at 86 while we continued to drive, not WOT etc. Pulled into a lot to cycle everything, no luck. Key on and off stuck red flag at 86 and it would not start. No tools (stupid me), not even to disconnect battery to see if it would reset. Did unhook TPS wire which showed 0 but plugged back in, red 86 stuck. Caught a ride home, got a truck and trailer and winched it on and back home. Unload and turn the key on, WALLA everything works. I also notice my alternator voltage is in yellow a lot. I have a new one as well as an 85 amp cop setup. Would voltage be the problem. Obviously I need this to be reliable on a two week race. Anybody have similar problem? Thanks

I've never seen the TPS stick not sure what is causing that. Guess you'll need to figure out if it is mechanically sticking open or if it is an electrical failure. My hunch would be electrical failure but could be either. You can replace the TPS but you would need to order one or call Holley and ask for a warranty replacement.

Voltage needs to be in the normal range for the Sniper to work so you'll need to figure that out for sure.

Did you run some data logs while you were taking the test drive? You should always data log your test drives so you can play them back and see what happened. Data logging is the basis for problem solving with a Sniper so if you aren't using the data logger then you're taking the hard road.

Data log? Have not learned that yet. Still waiting on my wire which should be here. Any experts on tuning within days drive of SW Louisiana? Thanks

Houston, we have a datalog. I did the 1st one on the small handheld. Rolling along about 20 and kicked it down with WOT. See pic...timing is green and red is rpm. The 2 slight rpm bumps are due to the lack of a baffle in my prototype tank when its low. Will address that later. A new alternator seemed to help solve yesterdays issues with no more yellow flashes. I still get a red box on TPS at 93 but I found that is how it is set in the wizard. Also found a knowledgeable shop/dyno etc about an hour away. Also note it auto shifted to 2nd at 4000ish. That's leaving some on the table for sure. Still pinging under load. Stephen

Put gas in it and no more cavitation. Made another run rolling in low and then WOT. Timing jumps to 26, falls to 22 then ramp to 34. Pinging bad the whole way. Any suggestions to continue breakin. I guess pull timing out and make another chart. Why the timing raise and drop at the hit? TPS 95 at WOT maybe that's why it shifts at 4000.Thanks

Discovered I was using "boxy" config file. Used the smooth one, still stair stepped but way better. Off to the tuner. Thanks guys. Phish

Okay, you're making progress. You can check the boxes on the left to look at other parameters on your data log. I'd suggest turning them on one by one to see what it looks like and then turn them off if you don't want to look at it.

The timing table needs to be nice and smooth so that is the first thing to do. I'm not sure on the pinging, that could be a bunch of factors including engine design and the type of gas you are running. First step is to put some premium in the tank, next step would be to try some high octane unleaded. Then try less timing or slow down the advance curve. There are a lot of variables to play with.

Have you verified that your timing is correct? You need to double check (or triple check) the timing at the damper with a timing light. The timing light needs to give you the same timing as what the handheld says. If the engine timing is different than what the Holley thinks the timing is then you'll have a big problem on your hands. It has to be verified.

Will do timing double check in am. Thanks again

Mr. A and Mr. T, you get cigars!!! My help thought sync of the dizzy was using plastic mold and marking number 1. He was within 8 degrees. Sniper at 15, balancer at 23. Moved the dizzy and checked again at 2000 and 3000 rpm. Bang on!! Now it does not ping and actually we could rally with it as is. Still going to have an EFI tuner check it. Also the new alternator engages the house battery (for smoke machine when we throw a rod LOL) and no longer have Sniper voltage flags. Guess I am a Sniper expert............Now to build a baffle in a new tank. Thanks Stephen

Yes, the plastic tool usually gets you close enough to start the engine but you always need to verify with a timing light before beating on it.