The 68-RFE is plagued by small overdrive clutch packs, a weak sprag, late torque converter lock-up, and inadequate line pressure. Typically, these issues can result in the failure of the stock transmission with just a mild tune or heavy trailer. ATS set out to create a product that addressed these concerns.
What is the ATS 68-RFE Co-Pilot? The Co-Pilot consists of a controller, harness and secondary electronics box. The harness plugs into the main transmission connector on the valve body. The harness is completely plug and play for easy installation. The controller mounts in the cab and allows the driver to adjust torque converter lock-up and shift firmness. These adjustments are made by depressing the up or down arrows. These changes can be made on-the-fly or with the vehicle stopped. The secondary electronics box is mounted to the driver?s side frame and requires no cutting or fitting.
What Does the ATS 68-RFE Co-Pilot Do? The Co-Pilot controls line pressure, clutch timing, by-passes the low sprag under high torque situations and locks the converter as early as 2nd gear providing there is sufficient engine torque. Line pressure is limited in a stock 68-RFE to 160 PSI. Unfortunately, this is not high enough to reliably prevent clutch slippage above 400hp.
The Co-Pilot reads boost pressure and throttle position to quickly take control of line pressure when it is needed. However, when the vehicle is driven lightly, line pressure is near stock for comfortable shifts. This is all done automatically in the controller. Line pressure is increased dramatically with the addition of a Valve Body Full Pressure Enable Kit. This kit is installed on any 68-RFE transmission built in house at ATS.
The kit can also be installed on a stock transmission to safely allow line pressure to increase to 270+ PSI. While the installation of the kit isn?t necessary, it will increase the performance of the Co-Pilot to its fullest potential. Clutch timing is programmed into the Co-Pilot and crucial to clutch pack life. On any 68-RFE transmission, clutch timing is optimized to reduce wear on clutch packs, efficiently transfer power and increase reliability.
The 68-RFE low sprag assists in transferring power between 1st and 2nd gear. With high mileage, or more power than stock, hard acceleration in 1st gear can cause the sprag to fail. Catastrophic transmission damage will result. The ATS Co-Pilot will keep the sprag engaged until the transmission shifts into 2nd gear to ensure for minimal chance of failure and loss of power throughout 1st.
The torque converter lock-up strategy on a stock 68-RFE leaves a lot to be desired. The factory TCM will command lock-up at a very low speed when at light throttle, this causes a sluggish condition, low boost and poor drivability. At higher power levels the factory TCM will not command the torque converter clutch until the throttle is reduced or a speed of over 45 MPH is achieved. By locking so late in the power band, a considerably amount of usable torque is unused. The ATS 68RFE Co-Pilot will lock the torque converter in 2nd gear, as low as 20 mph, under part or full throttle – along as the Co-Pilot senses there is usable power.
This allows the inherent torque of the Cummins engine to be used for better efficiency and performance. Modes Available in Co-Pilot Stock Mode This mode is entirely stock, meaning the Co-Pilot is not controlling any torque converter or transmission functions. Performance Settings In all performance settings the same base lockup table is used, which is based off the boost produced and APPS/TPS position. Lockup also occurs when decelerating in all modes, and will unlock around 26 MPH in most scenarios. Setting 1 This mode keeps the torque convertor loose to allow big turbo chargers to spool
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