The new CSF Auxiliary Radiators are a great addition to the massively successful G8X Cooling Suite. However, once you start adding a lot of power and pushing the car in aggressive driving conditions, the factory systems start to show its limitations. As more and more owners keep pushing the limits of their S58, CSF is here to keep them cool.
CSF has over 5 decades of experience manufacturing radiators. So when it comes to keeping your engine cool and your G8X M3/M4/M2 running at its best, CSF’s High-Performance Auxiliary Radiators are the obvious choice. Designed to perform on the street or at the track, performance aux rads are a must-have for both high horsepower builds as well as race vehicles which need added cooling performance in motorsports environments. These radiators feature 2-Row cores with CSF’s exclusive B-Tube Technology: Unlike a regular oval shape "O" type radiator tube, CSF uses a specially engineered tube in the shape of a "B". These "B-tubes" are carefully formed and then brazed over the seam to seal. CSF is able to use thinner and lighter aluminum material (with better cooling efficiency) because this design is actually stronger than normal "O" shape tubes that are welded. The design (inlet in the middle of the tube that is seam brazed) increases the heat transfer surface area of the tubes by approximately 15% over regular tubes - producing the efficiency of two smaller tubes vs. one large tube within the same space criteria. With "B-tubes" you are able to get "dual liquid laminar flow". CSF also uses ultra efficient multi louvered fins that are carefully and precisely aligned to maximize airflow through each radiator core. Fin specifications are carefully measured and calculated for each application, and tested for maximum heat rejection efficiency in CSF’s wind-tunnel lab.
Features
KEY FEATURES
- Sold Individually - all applications use 2 auxiliary radiators
- Multi-Fit - Fits Both Left & Right Side
- 2-Row - 42mm High-Performance Core Featuring CSF’s Exclusive B-tube Technology
- New "Track-Spec" 5mm Tall Ultra Efficient Fins with a Multi-Louvered Design for Maximum Surface Area Contact and Heat Dissipation
- Tank Volume and Core Size Increased
- 100% All-Aluminum TIG-Welded Construction
- OEM Style "Quick Connect" Inlet/Outlet
- True "Drop-in Fit" Requires No Modifications to Install
- Includes Detachable Rock Guard
- Individually Leak and Pressure Tested
- High-Performance Upgrade Suitable for Professional Racing, Street Performance, or OEM Replacement
- Satin Black Finish for OEM+ Look
- 2 Year Limited Warranty
CORE DESIGN
The CSF G8X M3/M4/M2 auxiliary radiators are a true "Drop-in fit" design requiring no modifications to install. OE style brackets are all CNC machined and welded for the best durability possible. Inlet/Outlet connections are designed to match the OE connections so you can reuse OEM hoses or aftermarket. Trust the cooling experts at CSF for the best performing, highest-quality, and most reliable radiators.
DESIGN & ENGINEERING
CSF designed the coolers to be a true "Drop-in Fit" for easy installation fitting both left and right sides. Each cooler mounts in the factory location and uses the OEM quick connections. The High-Performance Auxiliary Radiators work in conjunction with the rest of the cooling system to reduce temperatures. They not only help keep temperatures in optimal ranges, but prolong the heat soak threshold. There’s nothing worse than having your track session cut short because you need to do a cooldown lap.
CSF VS OEM
Compared to the OEM G8X coolers, the CSF units are a significant upgrade. The TIG welded aluminum tanks are much larger than the OE plastic tanks offering superior strength and fluid volume. A larger 2-row 42mm core increases cooling efficiency and capacity. This high efficiency core uses CSF’s Exclusive B-Tube Technology and latest 5mm fin technology, maximizing airflow and heat dissipation. These 5mm fins significantly increase the heat exchange surface area improving overall cooling efficiency and recovery while still maintaining good airflow.
100% All-Aluminum construction ensures the best performance and durability. The mounting pins and brackets are much stronger and more durable than the OE plastic pod mounting system. In addition, the black finish provides extra protection and offers a stealthy look behind the grilles of your G8X.
With many motorsports teams and race enthusiasts now pushing over 1000 horsepower, the S58 is seeing coolant temperatures well above normal. Once temperatures pass a safe limit the G8X will go into limp mode. Needless to say this can ruin a race, track session, or your overall driving fun in general. CSF is here to keep your S58 running at peak performance.
In addition, the CSF auxiliary radiators also feature integrated bolt on rock guards to keep the coolers safe. You’ve no doubt heard horror stories about OEM coolers getting punctured and spilling fluids all over the road or track. Now you can feel more confident that your cooling system is safer from road debris.
G8X S58 COOLING SYSTEM
The G8X S58 cooling system is decently complex. Diagrams have been included to show the details of how the whole system flows.
The cooling system consists of 6 to 7 heat exchangers depending on your transmission.
Because each auxiliary radiator is used for a different system you can elect to replace one at a time. For those looking to further improve the Charge Air Cooling system replace the right side auxiliary radiator. Those looking to improve the engine cooling system should replace the left side.
- 1. Oil Cooler: CSF #8266 – High-Performance Engine Oil Cooler
- 2. DCT Transmission Cooler: CSF #8221 – ZF8 Automatic Transmission Oil Cooler
- 3. Auxiliary Radiator (Right Side) – Charge Air Cooling System: CSF #8321 – High Performance Auxiliary Radiator
- 4. Front Mount Heat Exchanger – Charge Air Cooling System: CSF #8215 – High-Performance Front Mount Heat Exchanger
- 5. Radiator – Engine Cooling System
- 7. Charge Air Cooler – Charge Air Cooling System: CSF #8233/8233B/8233C – Charge-Air-Cooler Manifold
- 10. Auxiliary Radiator (Left Side) – Engine Cooling System: CSF #8321 – High Performance Auxiliary Radiator
INSTALLED MEDIA
Perfect drop-in fit in the factory location. The aluminum mounting pins on the CSF #8321 vs the OE plastic offers more stable mounting and overall durability.
SPECIFICATIONS
| Feature | CSF | OEM |
|---|---|---|
| Core Width | 42mm | 34mm |
| Core Rows | 2-Row | 1-Row |
| Fin Height | 5mm | 5mm |
| Tank Material | All-Aluminum | Plastic |
| Construction | 100% TIG-Welded | Crimp on Gasket |
REPLACES OEM PART NUMBERS
17118095285
WARRANTY
Limited warranty, 2 years, covering CSF High-Performance Cooling Systems under normal use and service (original purchaser).
Vehicle Compatibility
What’s Included
- 1x CSF Radiator
Availability & Shipping
In stock and ships from a US warehouse, typically within 1–3 business days. Standard Shipping applies to every order — rates are calculated at checkout, with tracking provided once your order ships. Some items may require additional processing time depending on the specific product and current demand. Track your order any time at eurospeed.co/pages/track for a live delivery estimate.
Delivery time depends on the product. Most in-stock parts ship within days, while carbon fiber and made-to-order items may require production time before they ship. For the specific timeline on any item, check the Availability & Shipping section on that product’s own page — the guide below covers our general shipping types.
Shipping Overview
Depending on the item, free air freight may be available for select carbon fiber components, with estimated shipping around 1–2 weeks after dispatch. Larger hoods, oversized body components, and certain made-to-order items may require sea freight and longer delivery windows. If timing is important, please contact us at support@eurospeed.co before placing your order.
Shipping Coverage
EuroSpeed ships to customers across the United States and internationally. Shipping is included in the price of eligible products for your convenience and covers the initial cost of delivery to your destination.
Import duties, taxes, clearance fees, or customs charges required by your destination country are not included and remain the recipient’s responsibility.
Order Processing & Fulfillment
Every order is reviewed, processed, and prepared before shipment. Most in-stock products are processed within 1–3 business days, though some orders may take up to 5 business days depending on fulfillment location, product type, order volume, or courier pickup timing.
EuroSpeed stocks select high-demand products at our U.S. facility and international fulfillment centers. Because our catalog includes many vehicle-specific and specialty parts, not every product is held in-house at all times.
Some orders may ship through our trusted fulfillment network, which may include verified manufacturing partners, authorized distributors, regional warehouses, and international fulfillment centers.
- Orders may ship from a U.S. warehouse, international warehouse, manufacturer, or authorized fulfillment partner.
- Some products may require additional handling, processing, production, or quality-check time before shipment.
- Orders enter fulfillment shortly after being placed and may no longer be eligible for cancellation once processing, production, or shipment preparation begins.
Custom, Made-To-Order & Oversized Items
Custom, made-to-order, and oversized product categories may include carbon fiber steering wheels, hoods, trunk lids, fenders, front lips, splitters, side skirts, diffusers, bumpers, body kits, widebody components, select spoilers, rear wings, and other large carbon fiber components.
Many carbon fiber items are made to order. Some products may already be stocked and ready to dispatch when available, but if inventory is unavailable, your purchase reserves the next available production slot instead of waiting for a separate restock listing.
Production time: Production can take 1–4 weeks depending on product type, selected options, finish, current queue, and quality-control timing.
Shipping time: Shipping can take 2–10 weeks depending on item size, freight method, destination, customs processing, carrier delays, warehouse transfers, and final delivery location. Carbon fiber steering wheels typically ship faster, with shipping usually taking 3–7 business days after dispatch.
By purchasing custom, made-to-order, or oversized items, you acknowledge and accept the extended production, fulfillment, and shipping timelines associated with these products.
Tracking Updates & Delays
All orders receive a tracking number once generated by the courier. Tracking may take 2–3 business days after dispatch to show movement in the courier’s system.
Certain international, oversized, or freight shipments may show limited updates during transfer between fulfillment locations, warehouses, customs, or final-mile carriers. In some cases, tracking is provided or begins updating once the item reaches a regional warehouse, local carrier, or final delivery network.
Shipping timelines are estimates and are not guaranteed. Delays caused by high order volume, weather conditions, customs inspections, carrier disruptions, production queues, warehouse transfers, holidays, or other external factors may occur and are outside of EuroSpeed’s direct control. These delays do not qualify for cancellations or refunds unless the carrier officially marks the package as lost.
Delivery Responsibility
Upon delivery, carefully inspect the item for visible defects or damage before signing for it. If the item is damaged or not as expected, do not accept the package. Once a damaged or defective product is accepted, EuroSpeed cannot cover return shipping costs.
EuroSpeed is not liable for packages marked as delivered by the carrier. If a package is lost, stolen, or missing after being marked as delivered, the customer must file a claim directly with the shipping carrier. Our team will assist with available documentation when needed.
Shipping addresses typically cannot be changed once an order has been marked as shipped. If an address change is possible through the carrier, any carrier redirect, correction, or address-change fee will be the customer’s responsibility.
Please ensure your shipping address is entered correctly at checkout. Orders shipped to incorrectly provided addresses are the customer’s responsibility. EuroSpeed is not responsible for failed deliveries, additional shipping costs, lost packages, or refunds caused by incorrect shipping information, failure to accept delivery, or failure to collect a package from the post office or carrier pickup location within the required time frame.
Customs, Duties & Import Fees
EuroSpeed’s free shipping policy does not include import fees, taxes, duties, clearance charges, or other fees required by your destination country. These charges are the responsibility of the recipient, and EuroSpeed is not responsible for any duties or taxes requested by local customs.
Most shipments clear customs automatically through the shipping provider. However, if additional information is needed to complete the process, our team will assist where possible to help ensure a smooth resolution.
If customs clearance fails and the item is returned or destroyed:
- EuroSpeed reserves the right to deny refund claims.
- Returned items may incur return shipping fees, which will be deducted from any eligible refund.
- Items deemed too costly to return may be destroyed, and no refund will be issued if this occurs.
Package Protection
For added peace of mind, EuroSpeed offers ShipInsure package protection as an optional service at checkout. When selected, this service provides coverage for lost or damaged packages. EuroSpeed is not responsible for shipping delays, lost packages, or damaged items if purchase protection is not selected during checkout.
- Protects against lost or damaged packages.
- Must be selected at checkout.
- Not all oversized body kit purchases are eligible. Please contact us before ordering if custom insurance arrangements are needed.
To file a claim, please visit our Claims Center.
- Claims must be filed within 14 days of delivery.
- Packages stuck in transit for 14 days are considered lost.
- Damage claims typically require photo evidence.
- A 2-day buffer after delivery may apply before lost or stolen claims can proceed.
- Police reports may be required for orders over $500 or where fraud is suspected.
- “Damaged” means the item is broken and unusable.
Questions?
For questions about your order, shipping timeline, customs clearance, or delivery status, please contact our team at support@eurospeed.co. We’re here to help.
Product Installation & Use Disclaimer
EuroSpeed is not liable for any damages, injuries, fitment issues, installation issues, or vehicle-related problems resulting from the installation, modification, misuse, or use of our products.
Products should be installed carefully and used only as intended. For complex installations, electrical components, performance parts, body components, or products requiring modification, professional installation is recommended to help ensure proper fitment, function, and safety.
Any damage caused by improper installation, misuse, modification, or failure to follow installation requirements is the sole responsibility of the customer. By purchasing, installing, or using this product, you acknowledge and accept all associated risks.