Transmission Control Modules for Hot Rods

If you are used to keeping everything under control, including the gear shifting process in your classic car, you should certainly consider using an advanced electronic transmission in your motorcar. If you make up your mind to give it a try, you will need an additional transmission module/controller to move the performance capacity of your car to a new level.

Designs of traditional mechanically-operated gearboxes (Powerglide, GM TH350/400, Ford C4/C6, and Torqueflite) included a set of vacuum modulators and RPM governors to keep track of shift points. It can be said that these are crudely made units and in many cases WOT shift points can be rather inaccurate. To get the precise WOT shift point, the driver has to perform upshifting or downshifting manually.

Ford C6 transmission

TH350 transmission

Older mechanically-operated gearboxes have to be partially disassembled for installation of shift improving kits intended for modification of the hydraulic circuits and line pressure increase. With more advanced electronically-operated gear shifting solutions, line pressure can be optimized with the help of the controller to adjust shifting firmness in accordance with the user's liking. It should be noted that these controllers cannot be considered as some kind of a cure-all solution for a weak gearbox, but when we are talking about a properly-operating electrified transmission unit, controllers can become a helpful tool in achieving a new level of the driving experience. Some of these solutions offer dyno mode which rapidly engages 3-rd gear and prevents any downshifting. Most systems also will block the TC clutch to exclude any possibility of the converter slippages.

To examine the most interesting solutions in the field of control modules, we will take a look at products currently offered by all the major brands in this segment of the automotive market.

Taking into account that all TCMs are responsible for the same set of operations, the selection process then comes down to examining and comparing of the main characteristics of specific models that may play an important role on the road. Simplicity in design is obviously an asset with its own advantages. For instance, PCS's Simple Shift utilizes dials instead of digital inputs which may be liked by users who prefer analog inputs.

Others may be lured by more compact design. Among the smaller solutions, we can mention the MSD's Atomic TCM that fulfills all the required functions and utilizes an easily-operated handheld device. MSD and the FiTech's Go Shift are also considered as budget-friendly version of the TCM.

Newer TCM solutions may be more appealing in several aspects. The latest designs frequently come with offer improved operating characteristics after eliminating drawbacks of detected in previous versions. One such solution is TCI's new TCU 2.0 system. This controller is not only packed with a range of helpful diagnostic indicators, but also has an upgraded software notable for its robustness.

It is also necessary to mention Edelbrock's autonomous controller, which is operated controlled by means of a wireless android tablet.

When it comes to reliability and durability, experts often recommend considering the HGM Electronics Compu-Shift. Moreover, it is worth mentioning that recently this technology has seen a lot of improvements. HGM engineers have redesigned its original controller by placing the electronics in a more space-saving package that is now named the HGM Sport. Moreover, they also managed to reduce the total cost of the unit thanks to the use of Bluetooth technology that allows you to install a free program on your smartphone or tablet, which will serve as a hand-held screen. Thus, you will be able to monitor a current state of the system and to introduce changes to its settings. It frees you from expenditures on a separate monitor, thereby reducing the cost of the whole system.

Learn more about HGM controllers

A large part of these TCMs will operate on a carbureted engine once a TPS sensor is attached to the carburetor. HGM offers a great conversion kit named the Acculink that helps to install a standard three-pin GM sensor on a variety of carburetors. Holley also offers a conversion kit, but it is intended for 4160/4150 carburetors that come with an electrical throttle.

It is also possible that some owners of performance-oriented cars may want to combine EFI system with an electronically-operated gearbox. FiTech, for instance, integrates controllers into particular EFI systems. Alternatively, customers may consider an EFI system to run the engine with a separate mechanism for the gearbox. We are talking about the systems that interact with the separate controllers via a CAN bus protocol. This communication protocol helps digital systems to rapidly transmit relevant operating parameters.

Holley has achieved similar results with its Terminator-X Max EFI solution. The Terminator-X Max is a budget-friendly multi-point EFI controller for LS engines that is also capable of controlling 4L60E/4L80E transmissions. As Edelbrock has recently released its controller and it wouldn’t be a surprise if at certain point the company will come up with the idea to combine its EFI and TCM into 1 package.

In terms of system options, we should pay attention to the MicroSquirt solution. Combined with the MegaSquirt EFI, this unit has a special shift retard feature that allows retarding ignition timing to ensure power reduction during the gear shifting process.

If you want to equip your car with an advanced 8- or 10-speed automatics, you have fewer options currently available on the market. These sophisticated gearboxes are much more complicated in terms of control, thus there are only two aftermarket TCMs intended for the latest automatics. The 1-st solution called the Quick 6 (operates with different versions of the 6R80) is provided by US Shift. The second is a PCS unit dubbed the TCM2650 that is designed for the GM 6L80E family.

All in all, it can certainly be said that transmission controllers will find popularity among speed fans who want to realize the full potential of transmissions installed in their performance-oriented cars.