Not only can the swirl flaps result in catastrophic engine damage they can also cause poor MPG and performance during their non-catastrophic ‘working’ period. Over time all flaps irrespective of their design become heavily coated in carbon and oil deposits from the EGR and breather system. This increases the size of the flap and in turn reduces the internal size of the inlet manifold, resulting in lost performance and efficiency.
How do you remove them?
The process for removing the flaps depends on the design, however in most cases the manifold is unbolted from the cylinder head, the flaps and connection rods are removed from the manifold and specifically designed blanking plates are fitted in their place. If the vehicle is fitted with an electronic swirl flap actuator the ECU is reprogrammed and the actuator function disabled.
We also recommend a Custom ECU Remap is carried out simultaneously with this modification, the remap is deigned to offset the small reduction in low end torque that can occur after removal.
What are the negatives?
In our opinion very little, the reduction in efficiency and performance at low engine speeds is almost unnoticeable and would only be relevant if no carbon build up had occurred. Due to the fact that carbon build up begins as soon as the vehicle leaves the factory, the removal of the flaps is likely to result in increased performance and efficiency. The fact that BMW stopped fitting swirl flaps to most vehicles post 2010 suggests that even the manufacturers have realised that swirl flaps offer more negatives than positives.
What does it cost?
The cost of removal depends on the design of the manifold and flaps, contact us with your vehicle registration and we will be more than happy to offer a quotation.
Give us a call on 01454 800 117 or email [email protected] for a free quotation.