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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
4.6 ★★★★★
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Product Reviews
★★★★★ 5
Very healing
I bought this for face but had also heard that this can be used for other skin issues. Yesterday, I cut my index finger with a label remover (basically a razor blade). Once I stopped the bleeding, I kept it clean and covered for a bit. Before bed, I decided to put a dab of this on my cut, when I woke up this morning, it's like a miracle! It barely hurts and looks quite healed!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 20, 2026
★★★★★ 5
It works... very well... for me. VERY WELL.
I typically detest American companies as many of the products contain both harmful and helpful ingredients at the same time. So far, Prequel has EXCEEDED my expectations.
PROS: It works for my skin. EWG gives good scores to Prequel also. Skin looks great afterwards. No scent. Lasts for hours with a healthy skin tone. You don't have to use a lot to cover an area (see below).
CONS: Slightly greasy when applied so it not a lightweight cream. Small tube (see below). Pricey.
You don't have to use a lot. I find that due to its slightly greasy nature, you can use much less to cover a greater area. Afterwards the greasiness disappears, leaving plump, healthy feeling skin texture.
As with any skincare product, your skin may react differently. I have tried major Western brands which worsened my skin (Cereva for instance) before switching to Korean & Japanese products (far superior). Prequel is now the only Western brand I will use on a regular basis, to include their bar of soap (superior to my regular Korean brand).
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Reviewed in the United States on September 14, 2025
★★★★★ 5
Great dry spot treatment!
Worked wonders on winter dry patches on my cheeks and sides of mouth. I’m a somewhat new Prequel product user. I follow the creator on YouTube and love her skincare videos. I have tried a few products so far and have been happy with the results. I just ordered the foot repair ointment for my husband as well. I think this brand is a great value for the money. I have not had any bad reactions so far and I have VERY sensitive skin. This ointment is lightweight and melts into my skin well and the next morning my dry spots were literally invisible. It’s fragrance free, I did not notice any scent at all, which is importance to me.
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Reviewed in the United States on January 3, 2026
★★★★★ 4
Prequel is always great
Very soothing and calming for skin. Tube lasted a long time. I have sensitive skin and often have reactions but did great with this.
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Reviewed in the United States on March 14, 2026
★★★★★ 5
This is a barrier cream?
I also have very oily skin, so normally I stay away from anything that says barrier or balm. I push skin a lot lol...with max strength tretinoin, glycolic acids, salicylic acids, vitamin C... so there are times when I just need max help from a richer product bc sometimes I take it too far. LRP Cicaplast has been a staple and has saved me many a times.
I bought this bc of the high percentage of ectoin, 5%, and it was so reasonably priced. When I squeezed the tube, I was really worried, it was thicker looking than the Cicaplast. However, when I spread it out, it was SO light and a tiny amount --barely a pea size, was enough to coat my face. It did not feel heavy. Even with my oily skin, I think I could wear this everyday.
As an experiment, I applied any excess on one side of my hand, as I'm right handed, I would apply it on my left hand. I've had this about a week, and right now after doing the dishes, and washing my hands multiple times without any hand cream on it, my right hand is definitely drier than my left hand. My left hand also looks less red and more calm.
This formula is 5 stars for both the effectiveness and the elegant formula. It may yet replace my LRP Cicaplast...we'll see!
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Reviewed in the United States on November 6, 2025
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