After a period of intensive development and testing, eight years ago we proudly announced the launch of the brand new and exclusive POWERVALVE Variable Tone Boost Actuated range of exhaust systems. With the introduction of this UNIQUE ‘game-changing’ technology, in one fell swoop. Powervalve Exhausts Ltd has taken the concept of the high-performance stainless steel performance exhaust system to a new level, by adding exhaust flow valve technology into its exhaust systems to greatly enhance their performance and audio characteristics. Exhaust flow valve technology has been around for a long time, with OEM manufacturers controlling the sound of their exhaust systems by diverting gasses into acoustic chambers on rear silencers to reduce sound levels to meet noise emission legislation.
Where the POWERVALVE design differs uniquely is that we use turbo boost pressure to control the opening and closing of our valves, which provides a constantly fluid environment for the exhaust gas to operate within. However, as the accelerator is depressed and the turbo starts to spool up, boost pressure is generated to further increase power, which enables us to harvest some of the boost pressure to activate our exhaust valves, this, in turn, opens areas of the silencer to allow a far more efficient low-pressure route for the exhaust gasses to flow through, resulting in the most optimum gas flow possible. In addition to the power gains offered by the POWERVALVE, the need to create the best-sounding system available was paramount in our thoughts. To this end, we refined the silencer design to reflect the need for the sound of the exhaust to change to mirror the demand for increased power. This is achieved by allowing the gasses to pass through an unsilenced section of the exhaust, once the frequency has passed beyond the level at which low-pressure bass waves are present.
So how does that work in application? Well put simply when the vehicle is operating off boost, gasses are circulating through a high-pressure part of the silencer, maintaining low down torque (a feature often lost in the past as bottom end torque was sacrificed for high-end power) and enabling, therefore, this highly efficient section of the exhaust system to meet strict noise emission levels. The exhaust sound transfer range varies between 74db and 98db and is ultimately controlled by the driver based on his driving style. Q. So why choose a POWERVALVE Exhaust system? A. Well, It’s all about passion Put simply, whilst production of our conventional stainless steel performance exhaust systems was going on we devoted time and energy to a completely new and radical concept of a variable tone exhaust system that whilst relying on the current technology found in exhaust gas control valves, did more than direct sound into acoustic chambers in rear silencers. Our design would be radical in that it diverted gas away from a direction that took it into an environment designed to reduce the sound to an OEM level, and into a section bypassing this entirely. In addition, this would also need to open the system fluidly to allow maximum flow of the exhaust gas to enable the new design to still outperform its rivals.
Crucial to this concept was the control of the valve. A high-performance turbo operating under the control of the ECU has its output and gas flow maintained under strict tolerances, perfectly balanced to match the finite gas flow volume that the OEM exhaust system can handle. Of course, once a performance exhaust has been installed and the ECU remapped to take account of the increased gas flow everything changes and boost pressures are able to be increased without overstressing the turbo. However, there are dangers at this sort of performance level in allowing control of, and the sudden transition of exhaust gas pressures into the hands of the driver. Imagine the scenario the car is running on a stage 2 + map pushing out huge bhp and it is decided that it might be fun to change the exhaust note by closing the gas control valve when the car is running at full tilt… No, the answer was to devise a new system that was boost controlled, thereby taking the control of both the power and sound out of the driver's hands in a sense, and transferring it to his right foot. With this system as the ECU responds to the drivers demand for power by creating boost, by careful control of diameters and valve spring pressures the gas flow is opened to maximum levels at just the right time, moving in an extremely linear fashion from essentially OEM gas flow levels to maximum levels in under a second. Nothing too technical there then you may think – until you consider the loss of torque sometimes experienced on mapped cars at low rev ranges as the time taken for the turbo to spool up and ‘pressurize’ the system is taking place. The POWERVALVE eliminates this by its transference of emphasis between low down running and high-end power, and of course, the best product of this process is the sound, which morphs from OEM levels to a full-on ‘Group N’ rally sound immediately the car starts to develop boost. As the boost drops off and the need for power reduces the sound returns to quiet levels, wonderfully addictive when entering and exiting islands, perfectly quiet on cruising. The POWERVALVE system is the embodiment of the popular phrase – ‘to have one's cake and eat it’ The POWERVALVE System is available for a variety of performance vehicles. Please contact us for pricing and application details, or alternatively why not review our range by searching for your vehicle from our exciting range…