I've been studying up on the Sniper system with the Hyperspark distributor and timing control. From what I've learned, the initial setup with the handheld programmer gives you "stepped" timing control where it abruptly transitions from initial timing to full advance with no "soft transition". There is capability to build your own 2D timing map and customize it for your engine, using a laptop or PC. Has anyone here already done some experimenting with this? What have you learned? This is the Holley video that explains how to develop the timing map. This is another good video explaining how to develop the map and a couple of other refinements. I completely understand how mechanical advance curves and vacuum advance curves work and have a good bit of experience with modifying distributors for SBC's. I have no experience with BBB's.......yet. My engine is going in a '49 Buick hot rod and will primarily be driven on long trips, so I want good gas mileage over extracting every last HP from the engine. Let's learn together.
Here is a good blog. https://www.efisystempro.com/efi-pr...ruction/holley-sniper-ignition-timing-control
Id like to know also as having just installed the full on Sniper system in the Wildcat. I noticed it does go from int of 12 to full 36 like flipping a switch.
I haven't personally worked in a sniper setup, but I have worked on other systems......and you should be able to make the timing curve do everything you can do with a regular distributor. Just picture your familiar swing line we are used to looking at and make it 3d. Only now you can hold off any advance till wanted and bring in as fast or slow as ever wanted to without all the spring and weight work. The actual concept if what needed by the motor is still the same, But now you can have a race map, cruise map, bad gas map, whatever
I will also tune it for economy, and have looked at the videos in the first post and read the articles on efisystempro I have made some very temporary ignition map using the recommendations in the "power timing your Buick" here in the forums and end up with the following map: This is of course just a starting point and will need to be tweaked when I get it out on the road and start tuning it. My temporary target air fuel ratio is like this: It should be a safe starting point and hopefully I can lean it out a bit in the "cruising" and idle part of the graph to around 16:1...
This tool looks like it will be helpful. It allows you to use an Excel spreadsheet to develop your timing table and converts inches of vacuum to MAP. https://forums.holley.com/showthread.php?49688-Tool-for-Creating-Timing-Table&highlight=table
Whoa.. back up there. When your working a timing map, you want the fuel on the safe side. Build your self a new tune, with the idle and cruise A/F targets one full point richer than you show here. Complete your timing map, and then ease back into leaning out the fuel. Does that sniper system have any learning capability?.. I have one on the shelf here ready to go on a procharged 430, but have not worked with that system yet.. have 4 or 5 Dominator/HP systems under my belt though, and love the capabilities. We typically dictated timing, and then let the engine tell us want it wants for fuel, beyond just a basic setup. Always start somewhat rich.. and let the program lean it out. On timing, yes, to some extent your trying to mimic what a timing curve looks like with a mechanical distrib, but don't limit yourself to that either. Engines with performance cams love timing advance at idle, I don't think I have ever run one at idle with less that 20*. Usually more like 25.. then you pull it back slightly when you get to the high loads at the torque peak, and then blend it back to best power setting at the HP peak. JW
The Sniper does auto tune using a wideband O2 sensor yes. Current tune is around 13.5 at idle and cruise and 12.5 at WOT. That is the starting point, this is my "wish list" that I give to the Sniper and it will build a learning table with the adjustments it need to get there. 20deg at idle? Hmm need to bump it up a bit then, what do you think about 35/36 at WOT? Suitable or can I add more there as well?
Most pump gas Buick engine I have tested on the dyno, want 34-35 degrees for the best balance between TQ/HP. The need for more advance at idle really depends on the cam you running.. small cams show little benefit from it, whereas the bigger stuff runs night and day different. When you say it auto- tunes, does it allow you to look at how much correction factor it's putting in, and the offer you the option to put that in your fuel map? That's how the bigger systems work. JW
Correct, It gives you a table that contains the correction factor, and one can then transfer that to the fuel map automatically, or manually, before smothing and hand tuning it to a good and complete table. That of course require some PC work, the handheld controller is fairly useless for tuning and I would recommend everyone to buy the CAN-2-USB cable but one can also dump the Sniper config and learning maps to the SD CARD and tune it that way. The handheld (and pc software) also give you realtime correction factor both short term and long term.
Here is some more useful information on using the EFI software. https://forums.holley.com/showthrea...or-Quick-Keyboard-Navigaton&highlight=hotkeys
My understanding is that the initial base map is determined by your input on engine size, number of cylinders, cam type, ignition type etc. The system then applies adjustments during driving in order to maintain the target A/F ratio. The 'learning' process creates an adjustment map that is then automatically combined with the base map in future use. It still applies adjustments to the combined map data based on feedback from the system. The handheld screen shows how much adjustment is being applied to the base map. both learned and from feedback. After putting a good few miles on the car you can use the handheld (no PC required) to write the learned adjustments into the base map. After this the handheld will show smaller or no adjustments during driving as the base map better reflects the cars needs. This is found on the handheld under "Advanced Learn" Transfer Table: When run is pressed, it will transfer the Learn Modifier table to the Base Fuel Table and Zero out the Learn Values. When “Run” is pressed the Sniper EFI will prompt if you would like to smooth the fuel table with the learned values. It is recommended you allow the Sniper EFI to perform the smoothing Bob
So, after putting 1000 miles on the engine and doing lots of troubleshooting and repair, I finally got around to doing some tuning. The first thing that jumped out at me when I downloaded the configuration file was the lack of "vacuum advance". If you expect this system to teach itself how to be efficient, it's not going to happen. I had been concerned that the engine was running hotter than it should, plus it really loved to drink gas! I experimented with and tried to learn how to use the laptop software today and finally got a configuration file in that looks pretty good to me and will absolutely use less gas. The first thing I notice was improved throttle response at low rpms, plus it appears to be running cooler. Stay tuned but don't buy into the concept that your system will teach itself to be efficient. You are going to have to do some work to get it close to being "tuned". The good news is you can do it and you can do it in the comfort of your air conditioned home. Kind of weird.
After doing a lot of head scratching and reading on this fine forum, I discovered I have a 5 vane water pump and, with my oversized 4 row radiator, I believe I am not getting enough fluid velocity for effective heat rejection. So, I ordered a Flowkooler pump today. Hopefully, I can report back in a week or so that my cooling issue has been resolved. Meanwhile, I'm off to the GoodGuys Nationals event at Columbus.
I stumbled across this article by Jeff Smith last week: HOW TO ADD IGNITION TIMING CONTROL TO YOUR HOLLEY SNIPER FUEL INJECTION SYSTEM Thanks,
