






CSF F87 M2 (N55) / F3X 340i/440i / F2X M240i High-Performance Auxiliary Radiator
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An industry-leading reputation and overwhelming success with BMW cooling has made CSF the #1 cooling choice for the F87 M2 (N55), F3X 340i/440i, and F2X M240i/M140i.
The new CSF Auxiliary Radiators are a great addition to the popular F87 (N55) & F3X/F2X Cooling Suites. Like the other cooling systems on these BMWs, the aux rads do a pretty good job in stock form. 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 M2s and Gen 1 B58s, CSF is here to keep them cool.
Click Here for the Full Press Release & Additional Product Details
FEATURES
- Sold Individually - most 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 5mm Tall Ultra Efficient Fins with a Multi-Louvered Design for Maximum Surface Area Contact
- 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
APPLICATIONS
| Year Range | Make | Chassis Code | Model | Trim | Engine / Trans / Etc | Notes |
|---|---|---|---|---|---|---|
| 2016-2018 | BMW | F87 | M2 | - | Turbocharged 3.0L L6 | Only Requires 1 |
| 2016-2018 | BMW | F3X | 340i | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2016-2018 | BMW | F3X | 340i xDrive | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2019 | BMW | F3X | 340i GT xDrive | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 440i | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 440i xDrive | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 440i Gran Coupe | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 440i xDrive Gran Coupe | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 430i | - | Turbocharged 2.0L L4 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 430i xDrive | - | Turbocharged 2.0L L4 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 430i Gran Coupe | - | Turbocharged 2.0L L4 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2020 | BMW | F3X | 430i xDrive Gran Coupe | - | Turbocharged 2.0L L4 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2021 | BMW | F2X | M240i | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
| 2017-2021 | BMW | F2X | M240i xDrive | - | Turbocharged 3.0L L6 | BMW: 17-11-8-625-447 Only - See Fitment Notes |
⚠ Fitment Notes
F3X 340i/440i and F2X M240i
Some F3X 340i/440i and F2X M240i/M140i trim levels did not come equipped with any Auxiliary Radiators. Be sure to check your VIN to see how many coolers your BMW came with before ordering.
There were three different Auxiliary Radiators available for the F3X 340i/440i and M240i/M140i. The CSF #8355 is made to be a drop-in fit replacement for the BMW 17-11-8-625-447. It can also replace the BMW 17-11-7-628-057 & 17-11-7-600-697 with the correct mounting bracket(s). Vehicles that did not come equipped with the BMW 17-11-8-625-447 from the factory may require minor trimming to the air ducting to fit correctly. Models equipped with the M Sport Package & M Sport Brakes should use the 17-11-8-625-447, however you should verify using your VIN with a dealership.
The Upper Brackets are the same for all 3 versions of the Auxiliary Radiators. The lower bracket part numbers are listed below. Please note, the frames (cradles) are not required as the CSF #8355 incorporates the frame (BMW 17-21-8-625-445) into the cooler design.
Lower Brackets for the 17-11-8-625-447
| Part Name | BMW Part Number | Qty. |
|---|---|---|
| Bracket, aux. radiator, lower left | 51-74-7-389-931 | 1 |
| Bracket, aux. radiator, lower right | 51-74-7-389-932 | 1 |
F87 M2 (N55)
Does NOT fit the F87 M2 Competition which uses the S55 Auxiliary Radiators (CSF #8258). The F87 M2 with the N55 uses a Single CSF #8355 Auxiliary radiator mounted on the Left Hand Side. The Right Hand Side uses the CSF #8104 Race-Spec Engine Oil Cooler.
OEM Part Numbers
- BMW: 17-11-8-625-447
- BMW: 17 11 8 625 447
- BMW: 17118625447
- BMW: 17-21-8-625-445
- BMW: 17 21 8 625 445
- BMW: 17218625445
Warranty
Cooling Systems and Flexibles, Inc. (CSF) warrants CSF’s High-Performance Cooling Systems, under normal use and service, to the original purchaser of the vehicle in which the product was originally installed. For more information and details please visit CFS Page.
SKU# 8355 Warranty Term: 2 years
Every CenCal order is eligible for Package Protection, powered by Redo. It is selected by default at checkout and covers your shipment against loss, theft, and damage in transit.
What it covers:
- Lost packages confirmed by the carrier
- Stolen packages marked as delivered but not received
- Items that arrive broken or damaged in transit
Resolution: Approved claims receive a full replacement at no cost. For damage claims, you keep the damaged item and receive a brand new replacement.
Claims must be filed within 7 days of the delivery date. See the full policy or email support@cencalmotorsport.com if you need help.
If protection is removed at checkout, CenCal cannot file a claim or accept responsibility for shipping issues.

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