FAQ
Quick Answers
What is MDS on a HEMI?
MDS is the factory Multi-Displacement System that can deactivate cylinders during light-load driving on supported HEMI vehicles.
Do I need a tune after an MDS delete?
Yes. A mechanical MDS delete needs matching calibration changes so the controller no longer commands cylinder deactivation.
Is this a cam tune?
No. This is a tune-only HEMI MDS delete product. Cam tuning is a separate tune path.
Does this support HP Tuners?
HP Tuners support is available for many compatible HEMI applications when the vehicle, controller, and stock read are supported.
Do I need to upload my stock file?
Yes. Upload your stock read, order number, vehicle details, and MDS delete notes through the JRJ upload portal after purchase.
Can I add transmission or drivability tuning?
Yes. Optional add-ons are available on the product page before checkout if your build needs extra calibration support.
Does this work on RAM, Charger, Challenger, Durango, 300, and Jeep HEMI vehicles?
JR Jones Racing supports many compatible RAM, Charger, Challenger, Durango, Chrysler 300, and Jeep HEMI workflows when the vehicle and controller are supported.