SKU: 76127050580

CSF Audi B5 S4 High-Performance All-Aluminum Radiator

Sale price$224.55 Regular price$249.50
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Ships within 48 hours · Estimated delivery Jul 14 - Jul 19

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Description

CSF Audi B5 S4 High-Performance All-Aluminum RadiatorWith over five decades of expertise in radiator manufacturing, CSF stands as a leader in delivering advanced cooling solutions. The CSF Audi B5 S4 High Performance All Aluminum Radiator is engineered to maintain optimal engine temperatures, ensuring your B5 S4 operates at peak efficiency under all conditions. Whether on the street or the track, this radiator is an essential upgrade for vehicles requiring enhanced cooling capabilities, particularly for

With over five decades of expertise in radiator manufacturing, CSF stands as a leader in delivering advanced cooling solutions. The CSF Audi B5 S4 High-Performance All-Aluminum Radiator is engineered to maintain optimal engine temperatures, ensuring your B5 S4 operates at peak efficiency under all conditions. Whether on the street or the track, this radiator is an essential upgrade for vehicles requiring enhanced cooling capabilities, particularly for high horsepower builds and motorsport applications.

At the core of this radiator’s superior performance is CSF’s exclusive B-Tube Technology. Unlike conventional oval-shaped "O" type tubes, the B-Tubes are uniquely shaped and seam-brazed to provide exceptional strength and durability. This innovative design allows the use of thinner, lighter aluminum material without compromising structural integrity, resulting in improved heat dissipation. The B-Tube’s inlet positioned centrally within the tube increases the heat transfer surface area by approximately 15% compared to standard tubes. This effectively delivers the cooling efficiency of two smaller tubes within the same spatial constraints, facilitating dual liquid laminar flow for enhanced thermal management.

Complementing the B-Tube design, the radiator incorporates ultra-efficient multi-louvered fins that are meticulously aligned to maximize airflow through the core. Each fin’s dimensions and placement are carefully calculated and rigorously tested in CSF’s wind tunnel laboratory to ensure optimal heat rejection performance. This attention to detail guarantees that the radiator can handle demanding cooling requirements while maintaining reliability and durability.

The CSF B5 S4 radiator is designed as a true "Drop-in fit" replacement, requiring no modifications during installation. All mounting brackets are precision CNC machined and welded to meet stringent durability standards. The inlet and outlet connections are engineered to match the original equipment manufacturer (OEM) specifications, allowing seamless integration with existing OEM or aftermarket hoses. This ensures a straightforward installation process and compatibility with all original components, including the AC condenser, mounting brackets, and fan shroud.

Features
  • 2-Row 42mm Core (Dual Core) Featuring CSF's Exclusive B-Tube Technology for Enhanced Cooling Efficiency
  • Core Equipped with Ultra-Efficient Multi-Louvered Fins with 6.5mm Fin Height to Maximize Surface Area Contact and Airflow
  • CNC Machined "Quick-Connect" Inlet and Outlet Connections for Precise Fit and Reliable Sealing
  • CNC Machined Brackets and Fittings Engineered for Superior Durability and Perfect Alignment
  • All-Aluminum Race Style Drain Plug for Convenient Maintenance and Longevity
  • Smooth Satin Finish Providing Corrosion Resistance and Aesthetic Appeal
  • "Drop-in Fit" Design Eliminates the Need for Modifications, Compatible with OEM Components Including Quick Connect Hoses, AC Condenser, Mounting Brackets, and Fan Shroud
Applications
Year Range Make Chassis Code Model Trim Engine / Trans / Etc Notes
2000-2002 Audi B5 S4 - Turbocharged 2.7L V6 (Manual) -
OEM Part Numbers
  • Audi: 8D0 121 251 AP
  • Audi: 8D0-121-251-AP
  • Audi: 8D0121251AP
  • Audi: 8D0 121 251 AP VAG
  • Audi: 8D0-121-251-AP-VAG
  • Audi: 8D0121251APVAG
Warranty

Cooling Systems and Flexibles, Inc. (CSF) guarantees its High-Performance Cooling Systems under normal use and service to the original purchaser of the vehicle in which the product was installed. This warranty reflects CSF’s commitment to quality and reliability. For comprehensive warranty details, please visit our Warranty Page.

SKU# 7071 Warranty Term: 2 years

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. 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
SKU: 76127050580

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4.3 ★★★★★
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justinmj411
Lowell, US
★★★★★ 5
Great water cup
Size: 40 Ounces, Color: Peony, Size: 40 Ounces, Color: Peony
Love this water cup! I like to use it around the house. I like how much water it holds, because I drink a lot of water. The color selection of these cups is really good too; I went with the peony cup. It is very vibrant and bold in color. I would say as for on the go, they can get pretty heavy if walking with it full of water, so maybe not the best choice if you are travelling by foot and carrying it. One thing I will say is that this keeps the water VERY cold for a long period of time! Definitely good in that aspect. The handle is very pleasant to hold too, as it has a soft silicon-like material along the handle, and feels very sturdy and thick. I do wish that the straw was more clear, but that isnt too hard to replace. If you want a water cup for around the house, I would reccommend
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 8, 2026
A
Verified Purchase
Allison Goar
Chelsea, US
★★★★★ 5
great purchase
Size: 30 Ounces, Color: Black Chroma
an amazing and gorgeous Stanley! big and keeps drink cold out hot for longer! high quality and worth the money.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 24, 2026
C
Verified Purchase
Carolyn
Grantham, US
★★★★★ 5
Great purchase
Size: 40 Ounces, Color: Rose Quartz 2.0
I was a Stanley skeptic. I couldn’t understand what the big deal was or why the internet was freaking out. I saw the video of the Stanley cup surviving the car fire (and I think the ice was still inside). So I tried it. I drink SO much more water now! I love decorating my Stanley with all the fun accessories and it holds a nice amount of water. It feels durable and good quality. I’ve had my Stanley for a year now and I’m even considering getting another so I can have one while the other is being washed. They are easy to clean as well because of the metal inside. There are two issues I’ve had since I got the Stanley cup. Once it was dropped, and the lid broke. Easy to buy more so not the biggest issue. The cup survived the fall just fine, not a mark on it. The other issue I keep having is my lid gets stuck and becomes hard for me to open sometimes. I have a bad thumb and wrist so often I have to have my spouse open it for me. It keeps my water cold all day. If I put ice in before I go to sleep it’s still cold in the morning. I love these cups and would recommend them to anyone looking to drink more water. If you like your water bottle you will drink more water and want to bring it with you.
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Reviewed in the United States on March 28, 2026
S
Verified Purchase
SaltyMango
Cuba, US
★★★★★ 4
Very strong and cute tumbler
Size: 40 Ounces, Color: Rose Quartz 2.0, Size: 40 Ounces, Color: Rose Quartz 2.0
Great quencher to get. I got this for my self and I love it so much. It's super cute and the color I got is a light soft pink. The size is big which is great since I like having enough coffee to last me all day. It keeps my drinks cold and warm or what ever temperature it is for a good amount of time which is great for anyone who is out for long periods of time. The quality overall is very good. The handle is big, comfortable and easy to grip and the quencher fits perfectly on my gym bag. Only downside is that it did get a smudge on it after I removed the paper that it had on the bottom. I tried removing the smudge it feels sticky like glue but it didnt get removed so I had to put a sticker over it to cover it up.
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Reviewed in the United States on May 5, 2026
L
Verified Purchase
LisaRose Wright
Louisville, US
★★★★★ 5
This is a great basic protective shower curtain
Color: 1a Peva Clear Premium, Size: 72"W x 72"L (Pack of 1)
This is a great product. It allows me to have a decorative curtain that won’t get water damaged or mildewed. The price point was right on and I will definitely be buying it again. Pros: The thickness is great. Not too flimsy. I was also impressed with the fact that there wasn’t a chemical smell like we often get with plastic curtains. It was very easy to put up and was just the right length to keep the water in the shower while it does a great job protecting the decorative curtain. It also has weights to assist it with hanging correctly. Cons: Make sure to spread it out after your shower to prevent water stains .
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Reviewed in the United States on March 1, 2026

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