Product Details: GFB puts the key to boost control in YOUR hands!

All turbocharged vehicles utilize some form of factory boost control, most of which display a tendency to be conservative in allowing the boost to build up, and then taper away noticeably toward redline. A GFB Boost Controller however, not only allows quick and easy boost level adjustment, but it can also reduce the boost threshold (the RPM at which boost starts to rise) and maintain a rock-steady upper limit.

Fits:  

Ford Laser TX3 Turbo 4WD KE - KHII (1987 – 1993)
    -The TX3, like many turbo cars, is limited in the boost that it can safely use by the efficiency of its intercooler and turbo compressor and the capability of its fuel supply system. Boost can be increased to the limit of the turbo's efficiency, for a good power increase, provided that intake air temperatures are kept close to ambient and enough fuel is available.  Boost increases should always be made carefully, with the aid of an accurate boost gauge.

Ford Telstar TX5 Turbo AS - AV (1986 – 1991)
    -The TX5, like many turbo cars, is limited in the boost that it can safely use by the efficiency of its intercooler and turbo compressor and the capability of its fuel supply system. Boost can be increased to the limit of the turbo's efficiency, for a good power increase, provided that intake air temperatures are kept close to ambient and enough fuel is available. For smaller turbos, like the one used on the TX5, better results are often had by increasing boost just a couple of psi, rather than pushing it too high and taking the turbo out of its efficency range.

Holden VL Commodore Turbo (1986 - 1988)
    -The VL Turbo uses a screw-in factory pop-off valve on the inlet manifold, which is nothing more than a spring-loaded overboost protection device. Typically these leak significantly, and should definitely be removed and plugged if you intend to raise the boost level.

Mazda 626 and MX-6 Turbo (1986 - 1991)
    -The Mazda 626 and MX-6, like many turbo cars, are limited in the boost that they can safely use by the efficiency of their intercoolers and turbo compressors and the capability of their fuel supply system. Boost can be increased to the limit of the turbo's efficiency, for a good power increase, provided that intake air temperatures are kept close to ambient and enough fuel is available. For smaller turbos, like the one used on the 626 and MX-6, better results are often had by increasing boost just a couple of psi, rather than pushing it too high and taking the turbo out of its efficiency range.

Mazda RX-7 S4 & 5 (1986 – 1991)
    -The main factor limiting the maximum safe boost level of a 13B turbo are the standard 2 mm three-piece apex seals. Factory boost is 6.2 psi for a series 4 RX-7, and 8.2 psi for a series 5. The reliable limit of these engines is 10 - 12 psi. If the engine is rebuilt and fitted with more durable 3 mm two-piece apex seals, then the engine will safely handle a higher boost level, although at above 14 - 15 psi, the factory turbo becomes inefficient and those seeking more power should install a high flow or larger aftermarket turbo.

Mitsubishi Starion Turbo JA - JD (1982 - 1987)
    -GFB recommend that an intercooler is fitted to JA - JB Starions before attempting significant boost increases. Without one, the boost could probably be increased 1 or 2 psi fairly safely, but adding an octane booster to each tank of fuel would be a good measure against engine damaging detonation. Intercooled JD Starions could probably tolerate 2 or 3 extra psi using high octane (98 RON) unleaded fuel.

Mitsubishi Cordia GSR Turbo AA - AC (1984 – 89)

Mitsubishi CC Lancer GSR (1992 - 1996)

Mitsubishi Lancer EVO

Mitsubishi Galant VR-4 (1990 - 1993)

Nissan 200SX SR20DET S14 – 15 (1994 – 2003)
    -The 200SX typically responds well to a modest boost increase, but the small factory intercooler poses the first restriction in the quest for power, being unable to scrub sufficient heat from the intake charge to ward off detonation at higher boost levels.

Nissan S13 Silvia & 180SX CA18DET

Nissan S13 Silvia & 180SX SR20DET

Nissan Skyline GTS-t R32
    -Skylines typically respond well to a modest boost increase, but the small factory intercooler poses the first restriction in the quest for power, being unable to scrub sufficient heat from the intake charge to ward off detonation at higher boost levels.

Nissan Skyline GTS-t R33 and GT-T R34

Nissan Skyline GT-R R32 (1989 – 1993)

Nissan Pulsar GTi-R N14 (1990 – 1994)

N12 Pulsar ET (1984 – 1987)

Nissan Z32 300ZX Twin-turbo

Subaru WRX MY94-96
    -The factory ECU cuts fuel if it senses boost exceeding 16-16.5psi (1.08-1.12 bar) for more than about half a second. It is common for these cars to easily handle boost increases up to this level. Beyond this, the fuel cut can be lifted or removed, but the small factory intercooler will limit the amount of boost you can run through it.

MY97-98 WRX and Version 3-4 STi
    -On the WRX model the factory ECU cuts fuel if it senses boost exceeding 16-16.5psi (1.08-1.12 bar) for more than about half a second. It is common for these cars to easily handle boost increases up to this level. Beyond this, the fuel cut can be lifted or removed, but the smaller factory turbo will start to run out of puff beyond 15psi, particularly at high RPM. It is common to see these models drop back to about 12-13psi by redline, even if peak boost is set above 16psi.

MY99-00 WRX and Version 5-6 STi
    -On the WRX model the factory ECU cuts fuel if it senses boost exceeding 16-16.5psi (1.08-1.12 bar) for more than about half a second. It is common for these cars to easily handle boost increases up to this level. Beyond this, the fuel cut can be lifted or removed, but the smaller factory turbo will start to run out of puff beyond 15psi, particularly at high RPM. It is common to see these models drop back to about 12-13psi by redline, even if peak boost is set above 16psi.

MY01-02 (MY02-03 in the U.S.) WRX and STi ("bugeye")
    -On the WRX the factory ECU cuts fuel if it senses boost exceeding 18psi (1.22 bar) for more than about half a second. Boost can be quite safely increased by a modest margin, and this model shows the biggest improvements, thanks to a lethargic factory boost curve. Very good low and midrange gains can be had by the installation of a boost controller.
    -The smaller factory turbo will start to run out of puff beyond 16psi, particularly at high RPM. It is common to see these models drop back to about 12-13psi by redline, even if peak boost is set above 16psi.
    -A word of warning on this model, there is a catalytic converter placed before the turbo in the up-pipe, and it has been known to fail with increased power levels (Subaru deleted this cat on the MY03 model). There is also an exhaust sensor in the same position, which can sometimes trigger the check engine light with increased power levels. There are a number of companies making replacement cat-less up-pipes for these models, which is worth looking into if you plan to modify your car significantly.

MY03-current (MY04-current in the U.S.) WRX and STi
    -On the WRX model the factory ECU cuts fuel if it senses boost exceeding 18psi (1.22 bar) for more than about half a second. Boost can be quite safely increased by a modest margin, but keep in mind with the higher compression ratio of this model, large increases should not be made without proper modifications. This model uses a smaller capacity fuel pump and injectors than previous models, so the safety headroom is reduced.

Subaru Forester GT (MY98 - 00)

Subaru Forester GT (MY01 - 02)

Subaru Forester XT (MY03 - 04)

Subaru Forester XT (MY05 onwards)

Subaru Liberty/Legacy GT (MY03 onwards)

Toyota Celica GT4 ST205 (1994 – 1995)

Toyota Soarer JZZ30 Twin Turbo 1JZGTE

Toyota Supra JZA80 2JZGTE

Additional Notes:

*Boost increases should always be made carefully, with the aid of an accurate boost gauge*

*Recommend having large boost increases performed on a dyno by an expert*