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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
4.3 ★★★★★
Based on 1174 reviews
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Product Reviews
★★★★★ 5
Vivid color and a wonderful audio sound!
Size: 24
Wow. With this price, the color quality of this monitor is amazing. Most surprising part is the speaker! The sound is so nice! My son use it to link his Chromebook to goto YouTube and enjoy to classic music played by Berlin philharmonic, wow!!! This is really a wonderful monitor!! Really a great product.
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Reviewed in the United States on May 21, 2026
★★★★★ 5
Nice monitor great value
Size: 24
I liked this so much I got 2. Nice size for a monitor, looks good, works good. No sound, camera or mic, so I bought a speaker and camera on Amazon too.
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Reviewed in the United States on April 21, 2026
★★★★★ 5
A quality product
Size: 22
great picture quality
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Reviewed in the United States on June 9, 2026
★★★★★ 5
Koorui 34E6UC (34" 3440×1440, 180 Hz, 1000R curved VA panel) — But Missing Info Buyers Should Know
Size: 34"/WQHD/1000R/HDR400
Review:
I purchased two of the Koorui 34‑inch curved ultrawide monitors for a dual‑monitor setup, and so far I’m very pleased with them. The picture quality is sharp, the brightness is solid, and the “Normal” color preset looks natural without any adjustments. For the price, these 34‑inch panels deliver very good performance.
That said, there are a few important details the product listing and reviews don’t mention — and knowing them ahead of time would have saved me some stress during installation.
1. YES, the 34‑inch model DOES include stand‑offs (spacers)
This is not mentioned anywhere in the listing, and even Amazon’s Rufus incorrectly says they are *not* included. They actually come in the small accessory packet with the manual.
If you’re mounting these monitors, you will need those stand‑offs because of the recessed VESA pattern. They are already in the box — just not advertised. I rushed to order a separate spacer kit because the listing didn’t mention it, so I’m putting this here to help the next person avoid that.
2. One of my monitors flashed briefly until I disabled FreeSync
On one of the two monitors, I noticed a quick bright “flash” when moving the mouse. Turning off Adaptive Sync / FreeSync in the monitor’s menu fixed it instantly. The other monitor didn’t have this issue, so it seems to vary by panel.
Not a defect — just something to be aware of if you see flicker or brightness pops.
3. Color and brightness match well once set manually
After setting both monitors to the same brightness, contrast, and color mode, they match very well side‑by‑side. The “Normal” color preset looks the most accurate on these VA panels.
4. Build quality and packaging are solid
Both monitors arrived well‑protected, and the included cables work fine. The stand is basic, but I’m using monitor arms, so that wasn’t a factor for me.
5. Too early to comment on long‑term support or durability
I’ve only had these monitors set up for a few hours, so I can’t speak yet to long‑term reliability or how responsive Koorui’s support is. I’ll update this review if anything changes over time.
Bottom line:
These 34‑inch Koorui ultrawides are excellent for the price, especially for gaming or a dual‑monitor setup. Just be aware that:
- Stand‑offs ARE included (despite the listing not saying so)
- FreeSync may need to be turned off on some units
- Picture quality is great once you match settings manually
- Long‑term support is still unknown
If the listing had mentioned the included spacers, it would have saved me a last‑minute order — so I hope this review helps the next person.
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Reviewed in the United States on February 12, 2026
★★★★★ 5
Awesome monitor! (my 3 year review)
So I've owned this monitor for about 3 years now and here's what I have to say about this monitor. The picture quality is actually really good. I got the 1080p version and I mostly use it with my Xbox series x and occasionally will use it for some lighter gaming on my gaming PC both work effortlessly well. The screen size is okay I think next time if it's in the budget I'll buy there 34 inch curved monitor. But for right now I'm sticking with this monitor until it dies and so far it's running strong 3 years later. Right now this monitor cost $80 which is an absolute steal at that price. I paid $130 for it and would say it's absolutely worth getting. There's no flickering. The setup process went smoothly. It's compatible with both my console and gaming PC! I absolutely love this monitor! I don't own the 27 inch version but I'd recommend going with either that size or bigger if you can afford it.
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Reviewed in the United States on December 10, 2025