Does a torque converter really have an effect on the performance of your vehicle?
The short answer is yes! This is true for stock engines as well as those that have had modifications. For proper performance and to ensure that the power gets to the wheels efficiently a torque converter needs to be matched to the torque range of an engine.
Torque converters used in factory configurations may be interchangeable between engines of similar power curves. Bolting a torque converter off a stock 202 onto a stock 173, or from a stock 308 one onto a stock 253 may not give any noticeable performance issues or degradation, but this does not mean that they will provide proper performance when coupled with engine modifications that push up the torque and power output of that engine.
Having spent time, effort and money to increase the amount of power your engine can produce, don't let the torque converter spoil it. The torque converter's job is to transfer the power an engine produces to the transmission and from there to the wheels, but if the torque converter is not matched properly to the new torque range of the engine the energy will be wasted through slippage and overheating of the torque converter. If you are using original equipment torque converters with your performance package you are, in essence, wasting that power. A torque converter designed to work in tandem with the engine will put the power back where it belongs - to the wheels.
No matter what, be honest with yourself about how you will use the vehicle. Most modified cars are street driven and only occasionally track smacked. Providing this vital information to a torque converter tech specialist would result in a converter that retains good street manners and driveability, but still has sufficient performance attributes to provide the thrills the engine mods can give you on the track.
Conversely telling the tech specialist that your street cruiser is "100 percent race car," when you're really intending to cruise around or only drive it on the freeway, will have you being provided with a torque converter that will only bring you frustration, discomfort and disappointment when you attempt to use the vehicle as truly intended.
After declaring your intent for your car, you also need to tell the tech specialist the weight of your vehicle, and the following information about the powertrain combination:
- Compression ratio
- Cam profile (duration at 0.050-inch lift, lobe separation angle)
- Carburettor or injector size
- Transmission model year and gear ratios
- Differential gear ratio