Impreza WRX & STI 94-00

Using GFB’s TMS technology the Mach 2 can help return the engine to peak boost up to 30% faster than a factory diverter valve when shifting gears (more information below).

• Recirculation model for direct factory replacement for performance without the noise
• Atmosphere venting kits to convert the recirculating valve if you want noise with your performance

Like the Respons and Deceptor Pro II, the Mach 2 is available in a range of bolt-on kits for most popular turbo models. And when we say “bolt-on”, that’s exactly what we mean! No additional adaptors, parts or vehicle modifications are required – simply remove the factory bypass valve and replace it with the Mach 2 – it’s that simple!

The Mach 2 is configured as a 100% recirculating valve (i.e. bypass, plumb back) and add on kits are also available to convert to 100% atmosphere venting.

Use the recirc model for direct factory replacement when you want the performance WITHOUT the noise! Add the conversion kit when you want some noise with your performance!

Factory bypass valves have two main shortcomings – one is that they are typically designed to start opening above a certain pressure to protect the engine, and the other is they are not optimised for throttle response. Oh, and you can’t vent them to atmosphere without stalling your engine…
The Mach 2 solves all of these issues. It can effectively hold unlimited boost (unlimited in that no turbo could ever produce enough pressure to damage it), and the TMS technology ensures maximum throttle response

Suits:

• 98-00 GT Forester
• 03-04 XT Forester
• 99-00 STI
• 98-03 Liberty GT & B4
  
  

Install Guide

Using GFB’s TMS technology the Mach 2 can help return the engine to peak boost up to 30% faster than a factory diverter valve when shifting gears (more information below).

• Recirculation model for direct factory replacement for performance without the noise
• Atmosphere venting kits to convert the recirculating valve if you want noise with your performance

Like the Respons and Deceptor Pro II, the Mach 2 is available in a range of bolt-on kits for most popular turbo models. And when we say “bolt-on”, that’s exactly what we mean! No additional adaptors, parts or vehicle modifications are required – simply remove the factory bypass valve and replace it with the Mach 2 – it’s that simple!

The Mach 2 is configured as a 100% recirculating valve (i.e. bypass, plumb back) and add on kits are also available to convert to 100% atmosphere venting.

Use the recirc model for direct factory replacement when you want the performance WITHOUT the noise! Add the conversion kit when you want some noise with your performance!

Factory bypass valves have two main shortcomings – one is that they are typically designed to start opening above a certain pressure to protect the engine, and the other is they are not optimised for throttle response. Oh, and you can’t vent them to atmosphere without stalling your engine…
The Mach 2 solves all of these issues. It can effectively hold unlimited boost (unlimited in that no turbo could ever produce enough pressure to damage it), and the TMS technology ensures maximum throttle response

Suits:

• 97-98 Impreza WRX

Install Guide

So how much more can you do with a blow-off valve? Well, the Deceptor Pro II takes the ‘Respons’ concept even further...

Deceptor Pro II features
Direct bolt-on for most vehicles available:

• Remote proportional venting bias/volume control- from silent to loud or anywhere in between
• Sleek, compact in-car BOV volume controller with backlit dial
• End point adjustment to control maximum vent to atmosphere bias setting
• Volume adjustment mechanism driven by a high-torque geared electric motor
• Durable, low-friction gear train supported by precision sealed ball-bearing
• Supplied with all parts and wiring required to have it up and running quickly and easily

Suits:

• 98-00 GT Forester
• 03-04 XT Forester
• 99-00 Impreza WRX & STI
• 98-03 Liberty GT & B4

Install Guide

So how much more can you do with a blow-off valve? Well, the Deceptor Pro II takes the ‘Respons’ concept even further...

Deceptor Pro II features
Direct bolt-on for most vehicles available:

• Remote proportional venting bias/volume control- from silent to loud or anywhere in between
• Sleek, compact in-car BOV volume controller with backlit dial
• End point adjustment to control maximum vent to atmosphere bias setting
• Volume adjustment mechanism driven by a high-torque geared electric motor
• Durable, low-friction gear train supported by precision sealed ball-bearing
• Supplied with all parts and wiring required to have it up and running quickly and easily

Suits:

• 97-98 Impreza WRX 

GFB's Short Shift kits are like no other. Until you feel the action of one for yourself, you won't believe the difference!

GFB's unique system means that not only is the shift throw distance fully adjustable, it can be reduced more than any other brand by a long shot (at the shortest setting, the throw from 3rd to 4th is a mere 55mm), whilst retaining the stock gearstick height.If you want a race-car feel when you change gears, look no further than a GFB short shift kit, the shortest throw shifter on the market!

GFB have re-designed their WRX lightweight pulley to provide even more benefits. It is now shaped to look exactly like the factory Subaru pulley, so it goes unnoticed in your engine bay - it even uses the factory belts! A significant amount of weight has been removed from around the rim for even better throttle response. The pulley weighs in at 578g (previously 790g), compared to the factory 2180g on the WRX and 2575g on the STI. This pulley will improve throttle response (particularly off-boost response) and allow the engine to rev more freely in the upper rev range.

It suits all Subaru EJ-series engines, and does not require additional belts

Featuring GFB’s patented venting bias adjustment system, the Respons allows you to precisely control how much air vents from each of the two outlets.

Why is this so important? Two key reasons:

Adjust how loud the blow-off sound is. Recirculate all of the air for silent factory operation, vent it all to atmosphere for maximum noise, or set it ANYWHERE in between to suit your preference.

Get a blow-off sound WITHOUT causing stalling, backfiring, or any other BOV-related issues, even on a car with a sensitive airflow meter (MAF).
Hold on, it gets better. The Respons isn’t just a noise-maker. It also;

• Offers better throttle response
• Faster boost recovery on gearshift
• Unlimited boost-holding!

For example, using GFB’s TMS (Turbo Management System) principle, tests show that the Respons can return the engine to peak boost up to 30% faster than a factory diverter valve when shifting gears.

Featuring GFB’s patented venting bias adjustment system, the Respons allows you to precisely control how much air vents from each of the two outlets.

Why is this so important? Two key reasons:

Adjust how loud the blow-off sound is. Recirculate all of the air for silent factory operation, vent it all to atmosphere for maximum noise, or set it ANYWHERE in between to suit your preference.

Get a blow-off sound WITHOUT causing stalling, backfiring, or any other BOV-related issues, even on a car with a sensitive airflow meter (MAF).
Hold on, it gets better. The Respons isn’t just a noise-maker. It also;

• Offers better throttle response
• Faster boost recovery on gearshift
• Unlimited boost-holding!

For example, using GFB’s TMS (Turbo Management System) principle, tests show that the Respons can return the engine to peak boost up to 30% faster than a factory diverter valve when shifting gears.