SKU: 65751080684

Holley Sniper EFI 4BBL Self Tuning System - Shiny Finish (HO550-518)

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Description

Holley Sniper EFI 4BBL Self Tuning System - Shiny Finish (HO550-518)HO550 518 SUPER SNIPER 4BBL EFI SYSTEM 800 cfm 4 Injector Throttle Body, 650 HP Forced Induction Part Number: HO550 518 Introducing Holley Super Sniper EFI! Looking to convert your blow thru carbureted turbo engine to EFI? Look no further than Holley for the Super Sniper 4150 EFI systems featuring 8, 100LB HR Fuel Injectors capable of supporting up to 1250 HP on forced induction or dry nitrous applications. Is your combination not producing that much

HO550-518 - SUPER SNIPER 4BBL EFI SYSTEM

800 cfm 4 Injector Throttle Body, 650 HP Forced Induction

Part Number: HO550-518

Introducing Holley Super Sniper EFI!
Looking to convert your blow thru carbureted turbo engine to EFI? Look no further than Holley for the Super Sniper 4150 EFI systems featuring 8, 100LB/HR Fuel Injectors capable of supporting up to 1250 HP on forced induction or dry nitrous applications. Is your combination not producing that much horsepower? No problem, Holley also offers a 650 HP four injector version for lower horsepower applications with a power adder or someone just needing additional sensor inputs. Did we mention the Super Sniper also has full nitrous control built-in? That's right, no need for a separate nitrous controller! Every Super Sniper EFI system also comes with a USB to CAN tuning cable, as well as free downloadable Sniper EFI Software to give you unlimited control of your engine.
Features:
650 HP version features four 100 Lb/Hr Injectors
Compatible with Draw-Thru or Blow-Thru forced induction applications
User-frie ndly Boost Control with handheld adjustability
Programm able Target Air Fuel Ratios per Boost level
Advanced boost control is available via free Sniper EFI tuning software, including Boost vs RPM and Boost vs Time - Same popular boost control offered in Holley HP and Dominator EFI systems!
2.5 Bar MAP sensor included which safely works on applications up to 21.5 PSI
Built-in Single stage progressive nitrous control
Dry or Wet Nitrous Support
Progressive or Non-Progressive control strategies
Lean/Rich AFR Cutoff
Time or RPM based Timing Retard and much more!
Integrated ignition timing control for precise timing curves
Programmable inputs and outputs
Three Programmable 0-5V Sensor Inputs for Oil/Fuel/Dome or Nitrous Pressure Sensors
Six Programmable Ground Outputs
One +5v Reference Output - +5V Power Supply for 0-5v Sensors
One Sensor Ground – Ground supply for 0-5v Sensors
Internal fuel pressure regulator eliminates the hassle of plumbing an external fuel pressure regulator (Preset to 58.5 PSI) for N/A or Nitrous applications
Self-tuni ng ECU means you don't have to be a computer/tuning wiz to have EFI!
Only 4 Wiring Connections Required! (Battery +, Battery-, Switched Ignition & RPM)
High-Resolution Full Color Touchscreen for initial Setup, Tuning, and Gauge Displays
Simple Calibration Wizard (Answer a few questions about your engine, and it creates the base map, then starts tuning on its own!) - NO laptop required!
The included Genuine Bosch LSU 4.9 Wideband Oxygen Sensor provides real-time Fuel Map Learn!
OEM Style TPS/IAC and fuel pressure regulator, for years of dependable service
Included clamp-on oxygen sensor kit ensures a leak-free oxygen sensor installation, with Stainless Steel T-Bolt clamps and a Stainless Steel (Weldable) oxygen sensor flange
Throttle body mounted ECU - no extra boxes to mount
USB to CAN Communication cable included for easy laptop tuning of advanced controls
Dual Pattern bolt on carburetor replacement, designed to fit 4150 Flange & Spread Bore manifolds - (Spread Bore Sealing Plate Part #9006 recommended)
Compatibl e with Holley EFI analog gauges and electronic dashes

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SKU: 65751080684

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4.1 ★★★★★
Based on 23 reviews
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Verified Purchase
Kiyoko Kanegae
Waukegan, US
★★★★★ 4
they're decent supplements
Size: 30 Count (Pack of 1)
my psychiatrist recommended these to me to help with my stress & anxiety induced insomnia but so far they don't really help a whole lot aside from making me a bit sleepy. it wore off pretty quickly the first few nights but overall i'd say they're pretty decent, just a bit on the spendy side to be getting regularly. they do cause some burping, though i expected that much going off of the reviews and it was only the first night i tried them.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 11, 2026
J
Verified Purchase
Jonathan Vaughan
Pawtucket, US
★★★★★ 5
A Powerful Anxiolytic and Sleep-Enhancer
Size: 30 Count (Pack of 1)
I have tried a plethora of non-pharmaceutical anxiolytics, and I can say that CalmAid is by far the most effective. For me, the effects are comparable to a low dose of Ativan, but without the drugged feeling. Here are the main things I notice: -Relaxed heartbeat. My heartbeat is usually very pronounced, but when I take lavender, it calms down dramatically. -Quieter thoughts. I don't know how to describe this except to say that the "volume" of my thoughts is turned way down on lavender. -Tremendous sense of calm. It's very hard to get upset or agitated or anxious while under lavender's influence. -Improved sleep. I've suffered from horrible insomnia for a long time, and lavender is one of the only remedies that's had a noticeable effect. It doesn't make me drowsy per se, but it makes me so calm and relaxed that sleeping is easier. However, there are some "side effects" (I use the term loosely) to be aware of when using this: -Reduced energy. I suspect this is just the lavender calming my stress response and revealing fatigue that's already present to some degree, but it's worth noting. As I mentioned, lavender doesn't make me tired, but it makes me just want to kick back and chill rather than doing anything very active or exciting. -Reduced motivation. Tying into the above, when using lavender I would often rather relax and watch a movie or read instead of getting work done. This is, I suspect, the dark side to being incredibly calm, whether it's lavender or something else making you that way. When you're calm, nothing seems to matter that much, including work. Ergo, you have less motivation. I think a certain amount of anxiety is healthy for optimal motivation, and lavender does away with that. -For these reasons, I don't consider lavender an optimal anxiolytic for social anxiety, because energy and motivation are so important in social situations. I suffer from social anxiety, and have used lavender to deal with this at times, and though it does make me less anxious, it also makes me less social. I'd recommend something more like phenibut for social situations. Despite these limitations, I still consider this an essential component in my anti-anxiety toolkit. I just try not to use it too often. Also, it's worth noting that human studies on lavender are somewhat lacking, and without more data, we don't know what the long-term effects of using it are. As with any drug (and I do consider this a drug), I think it should be used as little as possible. I would, however, much rather use this than a pharmaceutical anxiety medication. A final note, on when to take it: I've found the best time to be 30 minutes before bed, on an empty stomach. The effects are more dramatic when taken well away from food, and if you take it before bed, you get the sleep-enhancing effects immediately, and the anxiolytic effects all throughout the next day (it lasts a looong time).
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Reviewed in the United States on November 2, 2017
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Verified purchase
Boise, US
★★★★★ 3
Effective, but gave me a headache
Size: 30 Count (Pack of 1)
I did and do like these. I find it takes the edge off my anxiety. Oddly enough, they give me a headache the next morning. I tried only taking one pill at bedtime (instead of a second one halfway through the night); I made sure it wasn’t dehydration; I took electrolyte solution with it. I’ve pretty much eliminated anything else that a headache could’ve been caused by that I can think of. They work well enough for me that on some nights it’s going to be toss up and I will still take it. But it’s kind of a drag knowing that something natural that works has a residual headache the next morning.
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Reviewed in the United States on August 1, 2025
O
Verified Purchase
Olivia
New York, US
★★★★★ 5
Day 1 and A Week ish Later
Size: 30 Count (Pack of 1)
I was taking Olly Stress Relief gummies for a while to control anxiety, hyperactivity and racing thoughts, and they worked great. Recently I noticed that they were becoming a lot less effective and started searching for alternatives. This was my first choice and I've only used it this morning. Took one pill. So far I have noticed a lighter mood, lack of racing thoughts, and an overall feeling of being slowed down. I can focus on conversations better, and it slightly enhanced my ability to taste, flavors seem more vibrant.. I am a bit more "lazy feeling" as others mentioned, and I did get the lavender burps. They're not horribly obnoxious for me, just a bit different. Burps lasted maybe half an hour. So far I like it. Edit: it's been over a week now. The first few days I dealt with random headaches on and off, but did get benefits as stated above. After my body adjusted I stopped having the headaches and the "lazy" feeling. The lavender burps are still a thing and so is short term lavender breath right after taking a pill. You can describe it like a light lingering, kinda like toothpaste has a minty aftertaste, but lavender instead. For the most part I would still say it helps. It does not hit as hard as the first few days, but it is helping somewhat. Benefits for me: Less overstimulation in public, better ability to relax after work, anxiety is more "inconvenience", easier to focus, deeper sleep, less irritability. Cons for me: Short term lavender breath, vivid and unusual dreams, 2-3 day initial adjustment period for unpleasant side effects. What I'm doing: Taking one pill around 7-7:30pm daily with lots of water. Taking late to sleep off any potential unpleasant initial effects, and get better sleep.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 31, 2024
A
Verified Purchase
Amazon customer
Battle Creek, US
★★★★★ 4
Finally, a Calm That Feela Natural
Size: 90 Count (Pack of 1)
I've tried a lot of "calm" supplements over the years, and Nature's Way Calm Aid is one of the few I've actuallt reordered. I started taking it during a stressful stretch at work when my mind wouldn't slow down at night. Very shortly after taking it I felt more settled and less on edge. it takes the edge off without making me feel like I'm dragging through the day. The softgels are small and easy to swallow with no weird aftertaste. This has been a real game changer for me. If you're looking for something subtle but effective to help you stay calm and focused, CalAid is definitely worth trying.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 16, 2026

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