Specific Product Information

The T9488 VTA is a performance blow-off valve solution for Mercedes vehicles


If You Want Sound With Your Performance (Or Performance With Your Sound!), GFB’s T9488 VTA Delivers!


By combining atmosphere venting with the proven performance benefits of our ground-breaking DV+, the VTA delivers an aggressive blow-off sound, improved throttle response, as well as superior boost holding and reliability.


With its low-profile integrated solenoid and compact design, installing the T9488 is a breeze. Just swap out your factory diverter valve with the VTA, and you’re good to go!


Key features and benefits:

  • Blow off sound AND better performance
  • Reliable boost holding
  • Sharper throttle response, faster boost recovery
  • Low-profile integrated solenoid for seamless installation
  • Australian-made, backed by a lifetime warranty

T9488 is a direct bolt-on for most Mercedes turbo petrol vehicles. Twin-turbo engines typically require two valves.


Why Choose A VTA Over A “BOV Spacer”?

Whilst “BOV spacers” might offer a cheap way to get a blow-off sound, they fail to tackle the fundamental performance and reliability issues associated with the OEM diverter valve – all they do is redirect the vented air.


The VTA offers more than just sound. By replacing the OEM diverter valve you also get enhanced performance and reliability.


Reliable Boost Holding

Despite some improvements in reliability by the latest generation of OEM diverter valves, the performance trade-offs continue to grow. By locating the diverter valve on the intercooler piping rather than the turbo compressor cover, the risk of heat-related failures is reduced. However, boost leakage is significantly greater due to the plastic OEM diverter valve piston failing to seal on an uneven plastic seat.


The VTA effectively addresses this issue by incorporating an integral piston seat machined into its body, ensuring a reliable seal even on irregular plastic OEM seats.

Sharper Throttle Response, Faster Boost Recovery

OEM electronic diverter valves are binary in operation – they’re either open or shut. Your throttle, however, isn’t. When you make small throttle adjustments, the binary operation of the factory diverter results in abrupt changes in power delivery, which is the very definition of poor throttle response.


GFB’s patented “pilot actuation” system allows the VTA’s piston to open and close progressively, thereby smoothing the power delivery during throttle modulation, and ultimately improving throttle response.


Unrivalled Longevity, Backed By Our Lifetime Warranty

The combination of precision manufacturing, attention to detail, and robust materials means the VTA will last a lifetime. So does the warranty!

About this range

VTA Performance Blow-Off Valve Solution

US Patent Number 10077709

Chinese Utility Patent Nos:  CN206054094U & 206129406

PCT Patents Pending

The VTA is a performance blow-off valve solution for Audi, VW, Skoda and SEAT vehicles with an electronic factory diverter valve.

If you want sound with your performance (or performance with your sound!), GFB’s VTA delivers just that! By combining the proven performance benefits of our ground-breaking DV+ with atmosphere venting, the VTA delivers an aggressive blow-off sound, improved throttle response and boost recovery, as well as superior boost holding and reliability in extreme conditions.

The VTA shares the successful DV+ design philosophy:

“Keep what works, replace what doesn’t”

This means we retain ECU control and the solenoid from the factory diverter to ensure the fastest possible response time, without the added and unnecessary cost of replacing the solenoid like some brands do.

The weak part of the factory diverter has always been the plastic valve mechanism – this is the part we replace. The VTA features CNC machined billet components that last a lifetime, and we also change the valve operation method for better performance. The factory diverter valve can only operate in two states – open, or closed. When it opens fully at low boost, or during a partial throttle lift mid-corner, it causes increased lag and a noticeably non-linear boost transition.

GFB pioneered the use of “pilot operation” in the DV+, which works by re-purposing the factory solenoid to control the pressure behind the piston rather than the piston itself. This allows the solenoid stroke to be much shorter, speeding up the response time and increasing the actuation force. More importantly, it allows the piston to open and close progressively in response to the amount of boost pressure present, which smooths boost transitions and reduces the lag caused by the factory diverter valve.

It is this design philosophy that makes the VTA not only the best performing blow off valve solution, but also the best value on the market.

Key features:

  • TMS Technology for faster boost recovery on gearshift and during throttle modulation
  • Improved boost holding ability
  • Atmosphere venting for blow-off sound
  • Retains ECU control
  • Simple, direct bolt-on kits include everything you need to install
  • Manufactured in Australia in accordance with ISO 9001

VTA or DV+?

Depends if you want sound or not. Both valves are constructed with the same quality materials and valve mechanism, and both offer the same performance and reliability benefits. However, the VTA vents to atmosphere for sound whilst the DV+ recirculates the air to keep it quiet.

Why choose a VTA over a “BOV spacer”?

“BOV spacers” are cheap and they make sound. But that’s it. All the inherent performance and reliability issues you get with the factory diverter valve remain, because a spacer doesn’t change the diverter valve in any way. The VTA improves the operation of the diverter valve for sound AND performance.

Why choose a VTA over a kit that includes a solenoid?

Because there’s no performance benefit to replacing the factory solenoid, only a much higher price! If a VTA with the factory solenoid can open in a couple of hundredths of a second, why pay more than you need to?

Downloads & Installation

Vehicle Applications

VTA T9488 Suitable for Mercedes models also suits:


  • AMG GT 4.0TT (2019-On) Two Valves Required
  • A45 AMG (Facelift Models Only) (2015 - 2018)
  • GLC 200/250/300 (2015 - 2021)
  • GLC43 AMG 3.0TT (2019-On) Two Valves Required
  • GLA-Class X156 GLA180/GLA200/GLA220/GLA250 (2014-2019)
  • CLA-Class C117 CLA180/CLA200/CLA220/CLA250 (2013-2019)
  • CLA-Class C118 CLA180/CLA200/CLA250e 1.3T (2019-On)
  • CLA45 AMG (Facelift Models Only) 2016 - 2018
  • A-Class W176 A180/A200/A250 Turbo (2012-2018)
  • A-Class W177 A160/A180/A200/A250e 1.3T (2018-On)
  • B- Class W247 B160/B180/B200/B250e (2018-On)
  • B-Class W246 B180/B200/B220/B250 (2011-2019)
  • C-Class C300 2.0T (2019-On)
  • C-Class C180/C200/C250/C300 Turbo (Not Kompressor) 2011-2018
  • E-Class W212 E200/E250 (2009-2016)
  • E-Class W213 E200/E250/E300 (2016-2019)
  • E-Class W213 E200/E250/E300 (2016-2019) Note : M270/M274 ENGINES ONLY
  • S-Class S400 Note : Two Valves Required
  • SLK 200/250 (R172)
  • GLB-Class X247 GLB180/GLB200 (2018-On)
  • C63 & C63 S AMG 4.0TT (2016-On) Two Valves Required
  • S63 AMG 4.0TT (2018-2020) Two Valves Required
  • GLC63 & GLC63 S AMG 4.0TT (2018-On) Two Valves Required
  • E63 & E63 S AMG 4.0TT (2018-On) Two Valves Required
  • G63 AMG 4.0TT (2018-On) Two Valves Required
  • CLA35 AMG 2.0T (2020-On)
SKU T9488
Brand gfb