CSF BMW M2/M3/M4 (G8X) Transmission Oil Cooler w/ Rock Guard - 8221

The new CSF transmission oil cooler for the ZF8 automatic in the G8X M2/M3/M4 is engineered for high-performance and track-use applications. Featuring a unique dual pass design, the CSF Transmission Oil Cooler nearly triples the volume of the OEM unit and increases fluid capacity by ~94%.

The core features advanced micro-tube condenser technology derived from CSF's A/C cooling systems. Its 9-Channel Microtube design optimizes oil flow and offers maximum surface area contact. Installation is plug and play with the drop-in fit design. The CSF cooler retains OEM quick-connects and includes a replaceable rock guard for additional protection from road or track debris. This packaging helps preserve shifting performance, maintain optimal transmission oil temperatures, and extend transmission life in modified or race-prepped G8X M Cars.

Product Details

Their insight, experience, and testing feedback provided invaluable insight into designing the best cooler possible.

Design, Development, and Testing

While the OEM Transmission Cooler is adequate for the G8X in stock form, it starts to come up a bit short on modified/tuned vehicles. Specifically ones that see heavy track/competition use. Transmission oil temperatures have a major impact on the shifting performance of your automatic transmission. If the fluid passes optimal temperatures you will start to see some delays in shifting. Sluggish shifting can be quite frustrating, but the real concern is the damage that can be done to the transmission when temperatures get too high. There are often cases where drivers don't notice the change in shifting performance due to the gradual onset, but the damage is still being done slowly on a very expensive and important component.

Dual-Core Advantage

By changing from the OEM single core design to a dual core, CSF was able to increase the overall volume by 194%. This design offers a drastic improvement in heat dissipation and increases the fluid capacity of the coolers by ~94%. Utilizing CSF's AC Condenser Technology, a 1-Row Super-High Pressure 22mm 9-Channel Microtube design optimizes oil flow and offers maximum surface area contact. These features combine to offer the best possible heat dissipation from the system.

Rock Guard

CSF knows the kind of punishment the front of a car can take on or off the track. The wrong bit of debris flying through the front grille can quickly punch a hole in a cooler. Because the Transmission cooler sits at the very front of the center cooling stack, it is quite vulnerable to damage. In addition, "open face" race style grilles have become quite popular on the G8X. These grilles can add to the risk of debris passing through.

The factory grille is the only form of protection for the OEM transmission cooler. However, this still isn't the level of protection many race teams and enthusiasts are comfortable with. To address this concern, CSF has incorporated a replaceable rock guard to keep your cooler safe and your G8X running strong in the event of debris making it through the front grille.

OEM vs CSF

BMW OE 17-11-8-095-284/17-11-5-A49-5B9

CSF vs OEM

CSF #8221

The CSF Transmission Cooler features a unique dual pass design. You can see in the diagram below how the OEM Cooler's single pass design works by flowing across the core and back through a feed pipe. While perfectly functional, this gives some extra height to work with if you can eliminate the feed pipe.

The engineers at CSF came up with this unique design to take advantage of the extra vertical space while adding extra capacity and a dual pass system. This design essentially doubles the cooling capacity while still fitting perfectly in the OEM position with no modifications necessary.

Testing & Feedback

Studio RSR tested the new Transmission Oil Cooler on their G80 M3 Time Attack car during several events. The team competes in Global Time Attack events year round. In addition, their G80 M3 spends many weekends at the track to test new setups and modifications. Their experience and feedback on the real world performance of CSF products has been key in the development of all the new G8X cooling products.

There was a noticeable reduction in transmission temperatures on track. The combination of the transmission temps being in check and the new rock guard gave us extra peace of mind while on both the track and road.

Velocity Performance has also been running the Transmission Oil Cooler along with the Front Mount Heat Exchanger (CSF #8215) on their G82 M4 track car. They have been very pleased with the performance of both.

Thank you CSF and their team for always coming out with the best cooling products in the market. Not only do we mainly offer CSF to our customers at Velocity Performance also we tested the new Heat-Exchanger and also the Transmission Cooler from CSF on our G82 AWD M4 Time Attack Car. We immediately shaved 2 seconds effortlessly on just a practice set of tires!! Can't wait for the drop on all the other parts.

Thank you for always making the leading products in the automotive industry!