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- USA
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Ships within 48 hours · Estimated delivery Jul 12 - Jul 17
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Description
850CFM Ultra XP Carburetor - 0-80804HBXOverview: Xtreme Performance Holley Ultra XP carburetors! Ultra XP carbs are up to 38% lighter than our traditional race carbs, have fuel capacity that is 20% greater and 30 other new features! They're available in our all new Hard Core Gray hard coat anodized finish with Black billet for improved corrosion protection. They're also available in natural tumble polished aluminum with your choice of Black or Red metering blocks and base plate. The
Overview:
Xtreme Performance - Holley Ultra XP™ carburetors! Ultra XP carbs are up to 38% lighter than our traditional race carbs, have fuel capacity that is 20% greater and 30 other new features! They're available in our all-new Hard Core Gray™ hard coat anodized finish with Black™ billet for improved corrosion protection. They're also available in natural tumble-polished aluminum with your choice of Black™ or Red™ metering blocks and base plate. The Aluminum Ultra XP comes in 600, 650, 750, 850, and True 950-CFM. Holley Ultra XP carburetors offer new features such as an integrated idle bypass valve that allows for idle adjustments while maintaining the correct throttle plate to transfer slot relationship, high capacity fuel bowls which feature 20% more fuel capacity to eliminate starvation, integrated fuel shelf to minimize fuel aeration and internal baffling to control fuel slosh. Other features include all aluminum construction, fully tunable billet metering blocks, billet base plate, adjustable secondary linkage and knurled (hand adjustable) curb idle screws. Holley Ultra XP carburetors are the ultimate in square bore race carburetors!
Features:
- Aluminum Construction (saves 4.5 lbs - 38% weight savings)
- Hard Core Gray with black anodized billet aluminum metering block and booster inserts
- Designed for use on Drag race, circle track, or any high horsepower engines
- Contoured venturri inlet offers balanced airflow for increased horsepower
- Air bleeds moved outward to allow a smoother transition of airflow from the top of the carburetor into the venturii
- Metering blocks feature improved durability, true gasket sealing and fully adjustable (emulsion bleeds, power valve channel restrictors & idle feed restrictors)
- Integrated idle bypass valve eliminates the need for holes in throttle plates and allows for proper adjustment of idle while maintaining correct throttle plate to transfer slot relationship. Helps maintain good idle control when using radical camshafts.
- Dual 30cc accelerator pumps provide the perfect amount of fuel from idle to full throttle
- Fuel bowls provide 20% more fuel capacity while controlling slosh with internal baffling
- Clear sight windows on both sides of bowls for easy and safe fuel level adjustments
- Built in drain plug in front center of bowl provides easy access to empty contents of bowl
- 8AN (o-ringed) inlet threads offer a large variety of plumbing options and can be plumbed from either side
- 4 corner idle allows you to precisely control your idle system
- Mechanical Secondaries for perfect off the line launches
- Elongated (dual pattern) mounting holes allow fitment on intakes with square flange (Holley 4150™ style) or large flange (Holley Dominator® style)
- Knurled (hand adjustable) primary and secondary curb idle screws allow for easy idle adjustment without the use of tools
- Primary throttle shaft capped to prevent entry of debris & contaminates
- Factory machined accessory mounting hole for easy addition of adjustable primary throttle stop. New secondary pump cam lever designed to provide positive throttle stop on secondary side
- Stainless steel adjustable secondary link. Provides choice of 1:1 or progressivesecondary throttle actuation for ultimate control of secondary opening rate
- Baseplate designed with a boss that can be consumer machined for vacuum source
- Includes notched float and jet extensions
- 100% wet-flow tested by Holley technicians to assure it arrives ready to run!
Application:
| Year | Make | Model | Submodel | Engine Size |
|---|---|---|---|---|
| Universal |
Specs:
| Barrels | 4 |
|---|---|
| Billet Color | Hard Core Gray with Black |
| Booster | Down Leg |
| Brand | Holley |
| Carburetor Use | Professional Race |
| CFM | 850 |
| Choke | None |
| Circuit | 2 |
| Condition | New |
| Emission Code | 3 |
| Finish | Hard Core Gray |
| Fuel | Gasoline |
| Fuel Inlet | Dual |
| Marine Use | No |
| Material | Aluminum |
| Model | 4150 |
| Primary Main Jet | 84 |
| Primary Power Valve | 4.5 |
| Primary Pump Nozzle Size | 32 |
| Product Type | Ultra XP Carburetor |
| Secondaries | Mechanical |
| Secondary Main Jet | 84 |
| Secondary Pump Nozzle Size | 32 |
| Supercharged Application | No |
| Throttle Bore | 1.750 inch |
| Venturii Size | 1.563 inch |
| Warning | California Proposition 65 |
| Warranty | Limited 90 Day |
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
4.5 ★★★★★
Based on 303 reviews
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Product Reviews
★★★★★ 3
Works well but takes up more space than expected
Size: 2 Panel 8FT W, Size: 2 Panel 8FT W
This room divider does the job for creating a little extra privacy and was easy enough to set up. The panels feel decent quality and the wider feet help keep it more stable than some cheaper screens I’ve tried. My only issue is that it takes up a bit more room than I expected, especially with the feet sticking out. It’s still portable and folds away nicely, but definitely measure your space first. Overall it works well for separating a room or blocking off an area temporarily. i wish it came in other colors
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Reviewed in the United States on May 26, 2026
★★★★★ 5
Nice divider, serves it's purpose well!
Size: 3 Panel 12FT W
This room divider worked out very well for what I needed. I wanted a simple way to create a little more privacy and separation in a larger room without doing anything permanent, and this divider was an easy solution. The panels provide good coverage, and the black color gives it a clean, modern appearance that blends in nicely with different décor styles.
Assembly was fairly straightforward, and once set up, the wider feet helped keep the divider stable on the floor. I was especially happy with how flexible the panels are to arrange. You can keep it mostly straight, angle it around furniture, or create a more enclosed private space depending on the layout you need.
The material allows light to filter through slightly while still offering a noticeable sense of privacy. I’ve used it for separating a workspace area, but it would also work well in bedrooms, apartments, dorms, studios, or shared living spaces. Another plus is that it can be folded and moved without too much effort when you want to change the setup.
Overall, this divider delivers a good balance of functionality, portability, and appearance. It’s a practical option for anyone needing temporary room separation without installing permanent walls or curtains.
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Reviewed in the United States on May 26, 2026
★★★★★ 5
Perfect for Adding Privacy to a Piano Studio
Size: 2 Panel 8FT W, Size: 2 Panel 8FT W
I Ordered the 2 Panel version which is way too big for my needs... that's on me. So keep in mind that the picture shows a fabric made for two panels only being used on one and hence it is not pulled tight; it would pull tight and not be so wrinkly if it was set up properly as two panels. The metal pools that make up the panels seem to be well made, stable, and of good quality. They were very easy to put together and they stand up tall with plenty of height. The appearance of it with the fabric on it isn't as elegant as it could be, but it still looks good enough. The material is plenty solid, not allowing light through it, and thereby making a solid barrier. I am using it to block the view out the studio door when a student is sitting at the piano to avoid distractions from the hallway. It will allow a student to enter the studio with our distracting the student who is at the piano.
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Reviewed in the United States on May 18, 2026
★★★★★ 5
Room Divider That Gives Instant “This Is a Separate Space Now” Energy
Size: 3 Panel 12FT W
The Siebwin 3 Panel Folding Privacy Screen is surprisingly effective at changing the feel of a room without requiring construction, commitment, or somebody yelling about load bearing walls. The 12 foot width gives a substantial amount of coverage, making it useful for creating privacy, dividing open areas, blocking visual clutter, or setting up temporary sections within larger rooms. This saved us a ton of time and money in our new studio and enabled us to create a kitchen and office in one room.
The wider feet make a huge difference because flimsy room dividers that collapse every time someone exhales too aggressively are deeply annoying. This one feels more stable and grounded once positioned. The folding design makes it easy to move around or adjust depending on the space, and it folds down relatively compactly when not in use. It is basically the introvert curtain wall of dreams.
The material has a clean, neutral look that blends well into different room styles without screaming “temporary office cubicle panic.” It works well for apartments, studios, shared spaces, dressing areas, or simply hiding the mountain of chaos you swear you are going to organize tomorrow. Practical, portable, and refreshingly easy to use without turning setup into a three hour emotional event.
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Reviewed in the United States on May 16, 2026
★★★★★ 4
It's 2 panels holding 1 big privacy screen. Can't use as 2 separate 4' panels, but works great.
Size: 2 Panel 8FT W
This 2 panel privacy screen works well. Assembly was very straight forward, with easily labeled tubes. My son and I had it together in about 10 minutes, which was probably 3 minutes of me telling him to quit playing around and hand me the parts. It feels very sturdy, not likely to fall over or anything. The material fits well, with the Velcro being very strong. Measurements are all very accurate, with all pieces attaching properly. We have a similar privacy screen at work that we have to try and stretch out because the top and bottom Velcro doesn't fit quite right... this model does not have any issues though. The material is thin and light weight, but solid black so that you can't see anything through or behind it. I definitely think it's a great deal for the money.
What I think would have given it 5 stars though, is if you had 2 totally separate 4' panels instead of 2 panels with one big screen. It really wouldn't cost any extra to make it so that the screen was in 2 pieces and you could use it as 2 separate panels instead of having to use it as one big panel. It says 2 panel folding privacy screens, but it's really one big one that folds in the middle.
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Reviewed in the United States on May 25, 2026
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