GFB VTA T9460 DV+ Performance Blow Off Valve Sound by GFB
The VTA features CNC machined billet components that last a lifetime and cannot be damaged by high boost pressures or the associated increased charge temperatures. VTA T9460 DV+ Performance, Blow Off Valve Sound! The VTA is a performance blow-off valve solution for the Ford Focus RS. The VTA however allows the piston to open and close progressively in response to the amount of boost pressure present, so it only vents enough air to prevent compressor surge (the primary purpose of a diverter or blow off valve). In both cases, there is a risk to the turbocharger, as the ECU will attempt to compensate for a boost leak by increasing the wastegate duty cycle, which increases the turbo RPM significantly. The factory diverter valve found on these cars has two distinct issues reliability, and performance. On the Focus RS, there is no MAF sensor and hence no drivability or fuelling issues when venting to atmosphere. This helps to smooth out boost transitions, making the throttle response more linear and predictable, and also minimizes lag introduced by the factory diverter valve. Performance The factory diverter valve typically operates in only two states either fully open, or fully closed. Reliability There are two ways in which the factory diverter valve can fail the un-reinforced rubber diaphragm can rupture, and the metal valve stem that slides in the plastic cap can stick. When it opens at low boost, or during a partial throttle lift mid-corner, it causes increased lag and a noticeably non-linear boost transition, which is noticeable as a distinct step down in power as you roll off the throttle and the valve opens.
Tags: GFB VTA T9460 DV+ Performance Blow Off Valve Sound by GFB