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How smart is Holley Sniper EFI?

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How smart is Holley Sniper EFI?

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Old 08-12-2022 | 12:57 PM
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Default How smart is Holley Sniper EFI?

Candidly I am not a mechanic nor am I looking for 100% power or WOT out of my boat - what I want is simplicity.

Toying with the idea of using Super Snipers for my Weiand 177/MErcruiser 454 motors and have questions:

1) Is the Sniper smart enough to know if the gas is good quality octane-wise or not and adjust accordingly?
2) Do I have to replace my existing distributors to use the Snipers?
3) I hear they are sensitive to temperature and was planning to use 160-deegree thermos in the closed cooling - will they still work?

Thanks ( and sorry for Title typo - cant figure out how to fix it)

Swampy

Last edited by Griff; 08-12-2022 at 08:49 PM.
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Old 08-12-2022 | 01:35 PM
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Holley! oops
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Old 08-12-2022 | 10:39 PM
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1. NO
2. you should, and dont buy msd, sniper works best with their dual sync
3. yes
And keep in mind there is NO Knock sensor on a sniper so if you tell it to give it too much timing or have some compression and get knock, it will let er knock
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Old 08-15-2022 | 09:12 AM
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Everything Articfriends said.

I would add you don't have to replace the distributor, you can separate ignition control entirely from the Sniper, but there is no good reason to.
I use the sniper and the dual sync distributor on a 454, with 160 degree thermostat. Factory settings don't allow learning until ECT is above 160 but you can change this easily in the Holley software in the coolant temp enrichment table.
I have had only 1 oxygen sensor go bad on the water, however you can disable closed loop operation and get back home on open loop no problem once you have a good tune in it. (I carry an extra oxygen sensor anyway).
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Old 08-15-2022 | 10:02 PM
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Engine masters did a number of tests between sniper and carbs. The snipers weren’t even close when they checked cylinder to cylinder fuel distribution. I was thinking of doing the same. But everything I’ve seen I will stick to my carb. My engine starts great and idles great after only warming it up 30 seconds even in 59 degree water and I don’t have a choke.
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Old 08-16-2022 | 11:26 PM
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Some here have made the switch, but if you jump over to the Sniper group on FB, you'll find that there are a good number of issues out there. And if something breaks within the unit (think ECM), the whole thing has to go back to Holley for diagnosis and repair. I contemplated doing the swap, but the risks were too much for me.
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Old 08-17-2022 | 01:08 PM
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Yeah - I have wedges so I can put sensors in dry exhaust portion of my closed cooling system and picked up two guages so I can read A/F Ratios to tune em. Going to add electric fuel pumps to help with fuel delivery issues and see how the carbs work out.... then we will see. Thought Snipers would be "safer" with baby blowers and me not being a mechanic but seems like a lot of possible failure points.
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Old 08-17-2022 | 03:08 PM
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OSO’er Cms51 has a pair of 6-71 blowers for sale in the Swap Shop. Interestingly, the pictures show a pair of Sniper units sitting on top of those blower. You may want to reach out to him to see if he has any insights.

Single throttle body on a small blower… I think simple is better… carb (think 525sc).
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Old 08-17-2022 | 06:15 PM
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Originally Posted by TomZ
OSO’er Cms51 has a pair of 6-71 blowers for sale in the Swap Shop. Interestingly, the pictures show a pair of Sniper units sitting on top of those blower. You may want to reach out to him to see if he has any insights.

Single throttle body on a small blower… I think simple is better… carb (think 525sc).
we had bought the sniper kits after many talks with holley, but ended making major changes to the game plan of the project.
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Old 08-19-2022 | 09:04 AM
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Originally Posted by ThisIsLivin
Engine masters did a number of tests between sniper and carbs. The snipers weren’t even close when they checked cylinder to cylinder fuel distribution. I was thinking of doing the same. But everything I’ve seen I will stick to my carb. My engine starts great and idles great after only warming it up 30 seconds even in 59 degree water and I don’t have a choke.
Why would there be a difference? How is fuel from a carb getting distributed thru the intake different than a sniper which supplys fuel on top and the intake mixes it?
What season was this episode on?
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