My last post “Too Much Torque” was on the performance issues you might run into when your car is creating too much torque. The issues don’t end on the racetrack though, they continue in the shop. Increasing torque heightens the likelihood of mechanical problems throughout the car.
Torque increases wear and can eventually break both the engine and the drivetrain. Torque is calculated by multiplying cylinder pressure and displacement. Increasing cylinder pressure puts more load on all the engine components and is usually responsible for engine failures on modified turbo engines.
Torque is a twisting force, think of a torque wrench measuring the twisting force on a bolt. A dramatic increase in torque without supporting modifications will damage the clutch, gearbox, driveshaft, differential, and axles.
For example, I have recently been building a lot of S63 M5 BMW engines after connecting rod failures. While I can increase the strength of the engine components, it will always be possible to add enough cylinder pressure to break it again. Engines are limited by their weakest component, so the pursuit of torque is really a game of chasing the next weakest part of the engine. Increase torque, break a component, repair and repeat. This is a common BMW performance issue that we address when improving performance. The technical elements override the performance.
If we were to increase torque less and increase HP more when we modify the car, the car would go faster and be much more durable. This creates a better overall driving experience, costs less in repairs, and increases the lifespan of the car. Putting it simply, a vehicle’s performance (especially BMW performance) is only as solid as the technical and mechanical components.