The Weekly Waffle

Let's talk back pressure valves  Following on from my diagnostic and replacement here. We can waffle this week about the BPV or Back Pressure Valve fitted to DAF Mx-11 and mx-13 engines.  Once apon a time we use to have the exhaust brake and it's only job was to create some back pressure on over run.  How things have changed! With the introduction of euro 6 came smart actuators such as the VTG (you can find a bit about that here ) the EGR and the BPV. Now tasked with a multitude of different operations the BPV must now assist the PCI ECU in different operations such as: warming the engine up from cold achieved by creating a lower opening percentage of the butterfly valve. Assist and work in unison in creating backpressure for the EGR valve  Decreasing exhaust gas flow in the EAS system in order to heat up scr and the dpf element Adapt pressure situations in the turbo for better turbine rotor control.  create back pressure for engine braking.  Why is it s

OUT WITH THE OLD TURBO, IN WITH THE NEW TURBO How Turbos Have Changed In this week’s waffle I’m talking about the actuator used on the turbocharger on DAF mx-11 and mx-13 since euro 6 Variable Turbo Geometry plays an important part in efficiency and this was one of the big factors for replacement of the old internal waste gate turbocharger. NO SMOKE WITHOUT POKE We have a few components fitted to the turbocharger to enable correct operation as without a waste gate it can literally produce boost till it fails from oil starvation due to shaft speed or in bits from compressor surge, but in this week’s waffle we will focus on the actuator. One of the major components of the turbo is the VTG actuator. This component controls the direction of air via a nozzle ring at the turbine wheel How this operates is to increase the turbo rpm lower down in the rev range or slow it down higher in the rpm range, such as to control exhaust back pressure during exhaust BRAKE application . But having mechan