Selecting the right diesel torque converter is essential to handle power and allow for imiproved towing and fuel economy.
The torque converter is the vital link between the transmission and the engine. Although all torque converters use fluid-coupling to transfer and multiply torque, the rpm levels and speed at which the transfer of power takes place, vary depending on the application. For example, a racing torque converter typically has a high-stall speed, meaning it doesn’t begin to transfer torque energy until the engine reaches high rpm levels. Street converters connect at lower rpm levels and truck converters typically make use of the engine’s torque by allowing the torque converter to couple right off of idle.
Imagine then, a truck that needs to transfer its power right off of idle, but can produce as much as 600-1,000 lbs.-ft. of torque like a race car? That’s what a diesel torque converter has to do. Therefore, torque converter manufacturers had to evolve into the design of diesel applications to incorporate the power handling characteristics of a race unit, with all of the coupling aspects of a truck-towing converter.
Designing a true diesel converter began with analysis of what a new generation diesel converter needed. Diesel units have low redline shifting requirements of around 3000 to 3500 rpm as opposed to gas units that may not shift until 5000 to 6000 rpm. With that as the basis, manufacturers such as TCI Automotive began the process of designing a unit that could manage the torque needs of a diesel engine and be bullet proof as well. Both issues of efficiency and durability have been solved. TCI manufactures a diesel torque converter called the TruckMaster™, that is specially built to deal with the rigorous demands of diesel applications.
TCI® offers two styles of TruckMaster™ diesel converters. One is designed for the mostly stock factory engine and the other is for use with a diesel engine that is running with performance modifications such as a module or a computer that's been re-flashed to get more horsepower and torque.
The replacement unit for stock engines is a superior converter that lowers stall speed by 200 to 500 rpm's. This means that the diesel's torque is better utilized, which is especially good for towing applications. The converter also manages heat and slippage in a way a stock converter can't. It's equipped with a single lock-up clutch designed to handle 600 ft./lb. of torque. The design improvements of this unit ensure maximum efficiency for unchanged diesel engines.
For the diesel engine that is running numerous performance modifications, specialized diesel torque converters like TCI’s TruckMaster™ is a must. In some cases a chip or re-flashed ECU can deliver up to 200 ft./lb. of torque and as much as 100 more horsepower. Modifications such as nitrous oxide, methanol injection and upgraded turbos can result in well over 1000 ft./lb of torque. With that kind of change, a factory torque converter that's been designed for a stall speed of 1800 rpm, may respond by stalling at 2800 rpm.
A converter for this type of application requires improvements to the impeller pump, stator and the inclusion of a large diameter triple lock-up clutch that holds over 1000 ft./lb. of torque. This means that a converter with these improvements will handle new horsepower and torque dynamics like no other converter can.
High-quality torque converters also include production processes such as, fin angle adjustment, fin staking, fin brazing, and hub replacement. In addition to this, many performance diesel converters, like the TruckMaster™ are equipped with billet covers and heavy-duty mounting pads. You should also look for a converter in which the manufacturer puts it through a series of rigorous quality control measures. 
This includes such steps as critical dimension verification, where hub size, pilot size, turbine clearance, impellor fin angle, overall length and pilot to mounting pad measurements are verified.
So you can see how diesel converters developed and are designed for the performance requirements of various types of diesel engines and applications. Make sure that whatever converter you select, that it is fully tested and inspected. With higher power diesels it makes sense to opt for a converter that can keep all of your transmission parts in one piece.
Source
TCI Automotive
151 Industrial Drive
Ashland, MS 38603
(662) 224-8972
