Automatic Transmission Tuning

Nowadays numerous specialized tuning agencies and transmission services offer auto enthusiasts the opportunity to upgrade automatic transmissions. Such tuning operations may vary from reprogramming of transmission control algorithms to complete replacement of transmission parts. But it is important to point out that transmission tuning is a painstaking procedure which requires detailed analysis of desired changes and possible consequences of implementation of such transmission specialties.

Automatic transmission tuning includes the following methods:

• Reprogramming (chip-tuning/ TCU remapping). This type of tuning involves changing of software settings and reprogramming of shifting algorithms
• Quality tuning (replacement of auto/automatic transmission components) is directly related to application of transmission components made of high-quality materials. However, this type of tuning has no impact on functions and performance characteristics of the automatic transmission
• Complex (deep) tuning presupposes design changes of automatic transmission components that also leads to changes in qualities of these components, namely: engine RPM speed at the start, torque parameter, dynamics and sharpness of shifts, activation time of the transmission torque converter lock-up, etc

Helpful videos on transmission upgrades

Now we will review all tuning methods in more detail.

Reprogramming (chip-tuning/ TCU remapping)

The improvement of automatic transmission control algorithms is a promising direction in the field of car tuning. The chip tuning adopts the transmission to driving peculiarities of the driver. In addition, chip- tuning allows eliminating of delays in the transmission operation and selecting required gear ratio in compliance with road conditions. Upgrading of the automatic transmission control system facilitates obtaining faster gear changes and reduces the acceleration time of the car. The appearance of chip-tuning is conditioned by the possibility of improving the operation of the automatic transmission without interfering with the mechanical part. The transmission control unit contains the factory-supplied algorithm of the transmission control unit. With the help of special software it is possible to change required parameters.

The TCU remapping starts with installation of special software which helps to introduce changes in parameters of the controller. Depending on the desired result transmission specialists change the program embedded in the electronic control unit. As a result the automatic transmission operates in accordance with the car owner’s requirements: gears shifting speed increases, kick-downs become less noticeable, overtaking gets safer. In some cases (SUVs and crossovers), the controlling software reprogramming provides better off-road performance of the vehicle.

More advantages of chip-tuning:

• Change of stall speed parameter with unblocked brakes, from standstill up to 3,000 revolutions per minute instead of 2,000. Such adjustments increase the dynamics and speed at the start of movement

• Additional power and torque by relaxing the gearbox torque limiters

• Quicker gear shifts along with smoother gear shifting

• Faster reaction to tiptronic or paddle shift inputs (where fitted)

• Improved low speed and off the line response through earlier torque convertor locking

• Higher fuel economy in some gearboxes due to less power loss via the drivetrain

• Elimination of kick-downs and excessive jolts

But on the other hand, the main danger of the chip-tuning is the wrong adjustment of software parameters. As a result such mistakes may have the following consequences:

• Strong jerks when changing the gear ratio

• Slippage

• Insufficient acceleration rate

• Permanent oil overheating

• Deformation of automatic transmission parts

• Increase in fuel consumption

• Accelerated wear of friction plates

• Excessive increase of load on all elements of the powertrain and transmission

The automatic transmission chip-tuning must be approached in a comprehensive manner. Changes in the automatic transmission operation entail the necessity to change other systems of the car. Most of standard parts cannot handle increased dynamic loads, so simultaneously with the chip-tuning it is required to strengthen other car systems. It is impossible to implement chip-tuning in the correct manner without a special measuring stand. This stand helps to measure dynamic parameters before, during and after chip-tuning.

The question of environmental impact should be also considered when performing chip-tuning. All cars before official release are exposed to different types of testing in order to meet certain standards and control the level of emissions. The introduction of changes in the software may lead to changes in the engine operation mode and result in increased emissions.

The chip-tuning performed by professionals provides improvements in car handling and fully satisfies requirements of car owners. But it should be borne in mind that incorrect settings may damage the transmission and result in expensive automatic transmission overhaul, therefore it is necessary to weight up all pros and cons of this step and consult only experienced specialists.

Quality tuning (replacement of automatic transmission components)

The second type of tuning involves replacement of the transmission internal elements. This measure is aimed at improving technical parameters and reliability of the transmission by producing components using more advanced materials. New components are usually made of more durable materials such as Kevlar, composite materials or metal ceramics. The list of replaced elements usually includes:

• brake band pistons

• overrunning clutches and oil accumulators

• needle bearings instead of bimetal bushings

• polymer gaskets which replace paper gaskets

• additional cooling radiators

• pans with increased oil consumption

With proper approach this type of tuning provides higher transmission resilience and potential enhancement of the powertrain efficiency without any harm to the ride comfort. However, customized auto parts are quite expensive and usage of low-quality transmission components may completely neutralize the positive effect. The automatic transmission enhancement by replacing separate parts will allow car owners to extend the service life of their vehicles and make it possible to drive the car in severe conditions. Many car manufacturers and companies specialized in auto parts offer ready-made solutions to upgrade automatic transmissions. These solutions may be purchased and installed in specialized transmission service centers.

Complex (deep) tuning

This type of tuning is performed in all directions and affects the following parts of the automatic transmission:

- Torque converter. Within the scope of the automatic transmission torque converter, tuning specialists perform the following procedures:

• Upgrade of the pump blades and/or turbine wheel blades

• Installation of Kevlar linings on the lock

• Replacement of washers and bearings

• Installation of reinforced turbine

• In case of more advanced tuning car owners buy a sports torque converter

Check out how torque converters are tuned for drag racing:

- Cooling system. Specialists usually install another radiator which is connected to the standard system by means of the oil thermostat. The process of the cooling system tuning also includes installation of a thermal sensor with an electric valve (without it the automatic transmission will freeze in winter time and will be subjected to increased wear)

- Transmission oil pump. The oil pump is replaced by its analog of increased efficiency. This step helps to increase pressure in canals and prevents fluctuations. It is not so easy to find factory produced analogs or handicraft product of proper quality.

- Valve body tuning includes the following procedure:

1. Adjustment of the gear shift time

2. Pressure increase in the lubrication system

3. Pressure increase in the torque converter (higher efficiency)

4. Redesigning of the cooling system for faster ATF circulation

5. Installation of a new valve in order to avoid pressure drops during compression of friction clutches

In many cases specialists use Transgo kits for upgrading of valve bodies in automatic transmissions.

- Reduction of clearance spaces in the clutch using the thinnest type of steel and selection of sports frictions

- Competent selection of the planetary gear set with increased gear ratios for initial speeds

Actually, after this type of tuning the transmission body may be the only part which remains from basic configuration of the transmission.

In some cases an auto owner replaces the transmission in their car with a similar sports or upgraded off-road automatic transmission. This type of tuning is a complicated procedure which requires detailed analysis and calculations for optimization of installed transmission with the engine. Such operations can be properly executed only by experienced specialists.

All in all, the automatic transmission tuning turns out to be quite a complex and rather expensive undertaking. Generally, owners of old cars with low operating resource, admirers of aggressive driving style who like to test their cars under harsh conditions, and drag racing participants are the main customers of transmission tuning services. It should be also taken into consideration that any type of tuning may deprive the car owner of the factory warranty. All types of tuning have their pros and cons and require different financial expenditures, therefore it is up to the auto owner to decide whether it worth trying or not.