During DPF regeneration, exhaust temperature coming out of the particulate filter can reach roughly 1,100 degrees. That creates a real problem at the tailpipe, especially when some aftermarket systems run hundreds of degrees hotter than stock. CoolCuff fixes that by pulling outside air into the exhaust stream and mixing it before the gases exit the tip. We mapped temperatures along a stock truck with thermocouples, including at the DPF, six inches downstream, at the tip, and near the spare tire, then designed our system to beat those stock temperatures. The inlet shape and angle are computer-generated because the airflow has to enter at the right direction to do its job. The result is a cooler tailpipe during regen, with the dual exhaust version running another 40 to 50 degrees cooler than the single system.
The video focuses on Banks' Cool Cuff, a polished 304 stainless steel device installed inline at the exhaust outlet. Its purpose is to reduce exhaust-tip temperature during diesel particulate filter regeneration by mixing outside air with the extremely hot exhaust leaving the DPF. Rather than simply extending the tailpipe, the Cool Cuff uses a shaped outer cuff and internal vent features to direct ambient air into the exhaust stream before it exits the tip.
The engineering problem begins with the temperature of the exhaust during regeneration. As described in the video, exhaust gas coming out of the diesel particulate filter can reach roughly 1,100 degrees. That level of heat creates a serious concern at the tailpipe, especially on trucks where nearby components or surrounding materials could be exposed to the exhaust plume during regen.
Banks explains that the development process started with instrumenting a stock truck using thermocouples placed along the exhaust system. Measurements were taken back at the DPF, six inches out from the exhaust, and right at the tip. A thermocouple was also placed on the spare tire to verify that nearby vehicle components would not be overheated. These baseline measurements established the stock exhaust-temperature behavior during regeneration and gave the engineering team a reference point for what a safe system needed to achieve.
Using those stock measurements as the benchmark, Banks designed the Cool Cuff system to outperform the factory exhaust in terms of outlet temperature. The claim made in the video is that the Cool Cuff runs colder than stock during regen, while other aftermarket systems can run hundreds of degrees hotter than stock. The comparison is framed as a safety issue rather than a styling exercise: some hot aftermarket exhaust systems are said to produce enough heat during regeneration that a piece of cardboard held two feet from the exhaust tip can ignite. Banks states that avoiding that kind of result was a core requirement of the design.
The cooling effect comes from controlled air induction. The cuff contains vents that act as mixers, and the outer cuff geometry directs forward-facing ambient air into those vents. As the truck moves, outside air is captured and introduced into the hot exhaust stream coming from the DPF. That mixing lowers the temperature of the gas before it exits the tailpipe. The concept is simple in principle, but the video emphasizes that the effectiveness depends on the exact geometry of the inlets and the direction of airflow through the cuff.
Banks says the shape of the air inlets was generated in the computer rather than created as a simple stamped-and-bent feature. The inlet form is described as unique, and the angle of the bent metal is controlled by an engineering die based on the computer-developed design. According to the explanation, both the inlet shape and the bend angle are critical. If the vents are formed at too steep or too shallow an angle, the device does not work correctly. The final geometry was not accepted on theory alone; it was validated with field measurements taken on the vehicle.
The video then shows how the device is built into the exhaust. The vented feature is welded into the pipe, and the outer cuff slides over it with the opening facing forward. In that orientation, incoming air enters the cuff, is routed through the vent structure, and mixes with the exhaust stream before discharge at the tip. The use of polished 304 stainless steel is highlighted as part of the construction, indicating both corrosion resistance and a finished appearance, but the discussion remains centered on function rather than cosmetics.
The recap concludes with a comparison between Banks' single and dual exhaust configurations. The dual exhaust system is described as even cooler than the single-exhaust version, with an additional reduction of about 40 to 50 degrees. That final point reinforces the overall engineering story presented in the video: Banks measured stock behavior, identified the regen heat problem, designed a geometry-controlled air-mixing solution, validated it in the field, and produced an exhaust outlet that lowers tip temperature instead of increasing it.