We have developed a complete wiring and computer package to run the 5.7L/6.1L/6.4L Hemi engines and the Nag-1/WA580 transmission found in the LX cars and some Jeeps.
There is a common misconception that this transmission is not suitable for hotrod or muscle car projects. We have been successfully creating systems for
this transmission since 2007. The benefit of using this transmission over the 545RFE found in the trucks is that it can handle more input torque and it
has a slightly smaller size. Also, all of the Hemi motors from the LX cars and Grand Cherokees came with the Nag-1/WA580 transmission, these can usually
be purchased as a package for less than getting the engine and transmission separately. There are a few more items that are needed to make the transmission
shift properly and this is why it has not been the first choice for hotrods and muscle cars.
With some planning and understanding this transmission can work very well in your project.
The following items are required to make the transmission shift:
These items along with our new engine/transmission wiring harness (R-0028) and some custom programming make using the modern Hemi and Nag-1 transmission
a fairly straightforward project. Detailed information is listed below.
- Engine Computer
- Transmission Computer
- ABS computer and wheel speed inputs
- Factory shifter
- Front Control Module
It is best if you have a complete donor vehicle to get matching computers. There are some slight changes in the different years that can cause the parts
to not be compatible. If you cannot get parts from the same vehicle then stay with the same year whenever possible. You can call us to see if there are
any known compatibility issues with the parts you have.
You need to send as many of these items in to us as you can for testing on the new harness. At a MINIMUM you must send in the ABS computer and the Front Control
Module (FCM). All computers that you send in are connected to the new harness and tested with a OE scan tool to verify communication.
The factory engine computer comes with built-in security when pulled from a salvage vehicle. To use this computer in a hotrod/muscle car application will require that
we either remove security or we can use the factory ignition key and SKIM module from the same donor vehicle to make the security work as intended. We can provide a new
engine computer if you need one, the new engine computers do not come with security.
The transmission computer is a small black computer with two wiring connectors. See a picture of one
Here. A used TCM from a Hemi car is needed, we do not recommend purchasing a new TCM.
ABS computer and wheel speed inputs
The ABS computer must be sent in to us so that we can verify the wiring, there are a couple different types of modules and the wiring is different for each. The
purpose of the ABS computer is to provide wheel speed signals to the other computers. If you are using the rear-end out of a donor vehicle (LX car or Grand Cherokee)
then the speed sensors on those axles can be used. If you have an older rear-end then we have a tone ring and sensors kit that you may purchase to mount on the back
of your transmission. These signals are required to make the transmission shift properly. We do not recommend purchasing a new ABS computer. See a picture of one
The shifter module from a donor vehicle is required for this system. These shifters have a flat base so installation is fairly simple. The LX car shifter is a
shorter item than the Grand Cherokee shifter. You must get a shifter from a car that had the NAG-1/WA580 transmission. The early V6 shifters will not work. The
shifter is part of the computer system and tells the other computers what gear you have selected. It also provides the ability to use the +/- shifting feature.
Make sure you also get the shift cable and the wiring connector from the donor vehicle as these items will simplify installation in your vehicle.
Front Control Module
The Front Control Module (FCM) is the only part where we do not try to match model year with the other parts. For the FCM we recommend getting it from a 2006
vehicle. Any of the 2006 LX car or Grand Cherokee FCM modules will work. The FCM is a communications module used by the other computers in the system to share
information. It is a small silver computer that is bolted to the side of the fuse block in those vehicles. This module must be sent in to us so we can add wiring
directly to it, we may also need to do some custom programming to it depending on your setup. We do not recommend purchasing a new FCM.
Please call 479-243-9115 if you have any questions about your Hemi Nag-1/WA580 project.