O-Ring Actuator vs Diaphragm Actuator

If you’ve ever wondered about which type of actuator to choose among o-ring or diaphragm for your turbo, you’re welcome to join our discussion here. For Arashi Dynamics, we root for diaphragm actuators and we’ll discuss about our reasons later.

Let’s start from the fundamentals of both type actuators. A piston moves up and down bypassing the top actuator housing sealed by o-rings; during its movement the piston rubs against the housing, creating friction. With diaphragm type actuator, the movement is created by injecting compressed air, pushing the diaphragm and piston down to open the flap of the turbine housing.

Movement of diaphragm actuator is friction free, therefore the diaphragm does not wear out as fast as o-rings. Friction creates heat, and on top of the engine temperature, o-rings get stiffen due to the characteristic of Viton. In terms of maintenance, o-rings need to be lubed up constantly for proper stroke, once o-rings go dry, they will fatigue even faster. However, a little advantage of the o-ring actuator is that its housing design is smaller in size, therefore it reduces its chance of contacting other parts.

As for the efficiency, a diaphragm actuator has higher sensitivity over o-ring actuator and hence it responses to even slight pressure changes. Another important characteristic to consider is that diaphragm actuator does not leak due to its product design of barrier seal.

Now you’ve got better understanding of both type actuators, it shouldn’t be difficult for you to choose, and that is why at Arashi we offer only the diaphragm actuator.