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Description
Holley Sniper 550-841 EFI Stealth 4500, Shiny FinishOverview: Introducing the Sniper Stealth 4500 EFI System! Wanting to convert your Dragster or Pro street vehicle to Fuel Injection? Look no further! The Sniper Stealth 4500 EFI system from Holley features 8, 100LB HR Fuel Injectors capable of supporting 800 to 1500 HP naturally aspirated, or 800 1250 HP on forced induction applications. The Sniper Stealth 4500 also features multiple Input and Output options for sensor inputs and switched outputs to
Overview:
Introducing the Sniper Stealth 4500 EFI System! Wanting to convert your Dragster or Pro-street vehicle to Fuel Injection? Look no further! The Sniper Stealth 4500 EFI system from Holley features 8, 100LB/HR Fuel Injectors capable of supporting 800 to 1500 HP naturally aspirated, or 800-1250 HP on forced induction applications. The Sniper Stealth 4500 also features multiple Input and Output options for sensor inputs and switched outputs to control external relays. This system also comes with a USB to CAN tuning cable and free downloadable Sniper EFI Software give you unlimited control of your engine
Features:
- Supports up to 1500 HP Naturally Aspirated or 1250 HP Forced Induction with Eight 100 Lb/Hr Injectors
- Compatible with Draw through or Blow through forced induction applications
- 2.125" Throttle Plates, Flow 1440 CFM for large cubic inch engines
- 2.5Bar MAP Sensor
- Integrated ignition timing control
- Programmable launch control via 2-step and timing retard. Both can be triggered by a trans-brake input
- Gen 3 Ultra Dominator Style 4 Bolt Air Cleaner Flange
- -8AN Fuel Inlets
- 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
- Self-tuning ECU means you don't have to be a computer/tuning wiz to have EFI!
- The included Genuine Bosch LSU 4.9 Wideband Oxygen Sensor provides realtime Fuel Map Learn
- Built-in Single Stage Wet or Dry progressive nitrous control
- Three Programmable 0-5V Sensor Inputs for Oil/Fuel/Dome or Nitrous Pressure or other critical information
- Six Programmable Ground Outputs, Five programmable ground inputs. These can be used to trigger or control external devices such as nitrous solenoids, boost control solenoids. Or to provide the ECU with an Input to turn on function such as an ignition timing
- One +5v Reference Output - +5V Power Supply for 0-5v Sensors, One Sensor Ground - Ground supply for 0-5v Sensors
- Throttle body mounted ECU - no extra boxes to mount
- Only 4 Wiring Connections Required! (Battery +, Battery - , Switched Ignition & RPM)
- Required external fuel pressure regulator, 12-848 is recommended
- Customizable secondary fuel pump output (TPS, RPM or Boost enabled)
- User friendly Boost Control with handheld adjustability
- Free Software included comprehensive datalogging tool to help you maximize the performance of your engine
- Real-time datalogging to the included 3.5" Touch Screen, allows you to save information to the SD card without needing a communication cable
- Programmable Target Air Fuel Ratios per Boost level
- Advanced boost control available via free Sniper EFI tuning software, including Boost vs RPM and Boost vs Time
- OEM Style TPS/IAC, 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
- Patent Pending
Application:
| Year | Make | Model | Submodel | Engine Size |
|---|---|---|---|---|
| Universal |
Specs:
| Brand | Holley Sniper EFI |
|---|---|
| CFM | 1440 |
| Coast Guard Approved | Yes |
| Emission Code | 3 |
| Finish | Shiny |
| Flange Size | 4500 |
| Flange Style | 4500 |
| Fuel Pressure | 58.5 PSI |
| Height | 3.85" |
| Injector Size | 100 lb/hr @ 58.5 PSI |
| Inlet / Outlet Size | 8AN |
| MAP Sensor | 2.5Bar |
| Max Horsepower Rating | 1250 Forced Induction |
| Max Horsepower Rating | 1500 Naturally Aspirated |
| Product Type | Sniper EFI 4500 |
| Throttle Bore | 2.125 inch |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.9 ★★★★★
Based on 1590 reviews
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Product Reviews
★★★★★ 5
Nylabone Ring Bone
Size: X-Small, Color: Ring Bone
My dog loves these. She chews them into pieces which helps keep her teeth clean. It is a mess to clean up. She chews and spits out the pieces. She is 6 years old so not a puppy.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 29, 2026
★★★★★ 4
Everything a Teething Puppy Could Need — Well-Thought-Out Kit
Size: X-Small, Color: Teething Bone
The Nylabone New Puppy Starter Kit is a solid all-in-one solution for the first few months of puppy ownership. It comes with multiple chew toys and bones designed specifically for teething puppies, and my little one took to them right away. The variety keeps him engaged, and I appreciate that each item is designed to be gentle on developing teeth while still satisfying his urge to chew.
What differentiates this kit from other puppy chew sets on Amazon is the thoughtful selection of textures and shapes. It’s clear these toys are designed to stimulate gums, promote healthy chewing habits, and even support dental care. I also like that everything is non-toxic and durable enough to survive a few enthusiastic chews.
The only reason I didn’t give 5 stars is that the kit might be a bit small for larger breeds, or for puppies that are particularly aggressive chewers. But for standard small to medium pups, it’s a fantastic starter kit that keeps both puppy and owner happy.
✅ Bottom line: A reliable, well-designed starter kit for teething puppies which is thoughtful, durable, and engaging. Makes a great gift for new puppy owners or a practical addition to your own puppy’s toy collection.
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Reviewed in the United States on September 26, 2025
★★★★★ 5
Chew
Size: X-Small, Color: Ring Bone
My dog loves this little chewy bone and it’s good for her teeth. That was very cheap on a sale. It’s worth giving it a try highly recommend it.
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Reviewed in the United States on June 11, 2026
★★★★★ 3
Chicken Flavor Good, But 🔄 Rotation-Resistant✖; Best for Simpler Chewers
Size: X-Small, Color: Ring Bone, Size: X-Small, Color: Ring Bone
🐾 Hi, I’m PVD; plush sophisticate, chew critic, and active curator of rotational toy relevance.
This ring bone and I never fully bonded. I sampled it maybe five times in my entire puppyhood before quietly returning it to the bin (with a single judgmental glance).
Still, it does have value for the right pup.
⭐ Why I originally wanted to love it:
✔️ XS size works well for very young puppies
✔️ Chicken flavor lasts impressively long
✔️ Freezing offers temporary gum relief
✔️ Durable and safe; no odd odors or shredding
🌀 Why it’s now a respectful 3-star chew in my rotation:
✘ Never became a go-to toy (5 uses max in my life)
✘ Ring shape felt awkward, not natural or chic; hard to grip and maneuver
✘ Texture too tame vs. nubs or detailed chew surfaces
✘ When I was smaller, I much preferred the Nylabone Baby Blue Bone Chew Toy with nubs (my personal classic), and have since matured into nightly Nylabone “Nubz” edible bones
This Ring Bone is Best For:
• Very young puppies with minimal chew preferences
• Dogs who like simple textures and circular shapes
• Those just starting enrichment chew play
• Freezer treat rotations (briefly)
🚫 Not ideal for: picky pups, advanced chewers, or dogs who analyze toy ergonomics (like myself).
📝 Final Re-Barks:
A strong, well-made chew, but lacked the intrigue to make my permanent rotation. Works for basic chew enjoyment; not for pups with elevated taste or toy ambition.
— PVD (Chew Strategist, Textural Analyst & Aspire-to-Vine Reviewer 🐶💼)
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Reviewed in the United States on September 17, 2025
★★★★★ 5
Puppy loves it!
Size: X-Large, Color: Teething Bone, Size: X-Large, Color: Teething Bone
My small puppy loves this bone! I originally purchased this for a larger dog, but my small 10 pound puppy loves it more. It’s good quality and a softer material for puppies!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 10, 2026