G Series: A Turn Ahead Of The Competition

G Series G55 turbochargers feature the latest innovations in turbocharger technology. Advanced compressor and turbine aero offer a range of high horsepower performance boosting solutions for 3.0L – 12.0L engine platforms. 85mm, 88mm, 91mm, 94mm, 98mm, 102mm, 106mm compressor inducer sizes produce up to 2900 horsepower for today’s top drag race teams.

Turbine Stage:

The newly engineered turbine wheel with optimized G Series aerodynamics increases flow up to 15% (Compared to GTX Gen II, see graph below). The large 90 trim turbine stage measures 112mm at the inducer and 106mm at the exducer. G55 is offered with stainless steel turbine housings in:
V-Band Inlet: 1.24 A/R, 1.40 A/R
T6 Inlet: 1.00 A/R, 1.12 A/R, and 1.24 A/R, 1.40 A/R

Part Numbers

• 1.24 A/R: 761208-0069 (V-band inlet & Outlet)
• 1.40 A/R: 761208-0070 (V-band inlet & Outlet)
• 1.00 A/R: 761208-0071 (T6 inlet & V-Band Outlet)
• 1.12 A/R: 761208-0072 (T6 inlet & V-Band Outlet)
• 1.24 A/R: 761208-0073 (T6 inlet & V-Band Outlet)
• 1.40 A/R: 761208-0074 (T6 inlet & V-Band Outlet)

Center Housing:

One-piece aluminum center housing reduces supercore weight. The center housing is air cooled, features a 16mm ceramic dual ball bearing for premium rotor dynamics, and retains the oil inlet and outlet specifications from previous GTX designs.

Compressor Stage:

Garrett G55 compressor stages are offered in 85m, 88mm, 91mm, 94mm, 98mm, 102mm, and 106mm inducer sizes each with their own horsepower ratings indicated in the model name.

Turbine Housings:

Stainless steel turbine housings in T6 and V-Band inlet and V-band outlet

Short outlet (SFI certified not available)

V-band inlet: 4.25 inch (108mm) (same as GTX55)

V-band outlet: 5.15 inch (131mm) (same as GTX55)

Ceramic Dual Ball Bearing

An oil restrictor is recommended for optimal performance with ball bearing turbochargers. G55 turbochargers utilize a massive 16mm dual ball bearing cartridge with steel cages. An oil pressure of 40 – 45 psi at maximum engine speed is recommended to prevent damage to the turbocharger’s internals. In order to achieve this pressure, a restrictor with a 0.040” orifice will normally suffice, but you should always verify the oil pressure entering the turbo after the restrictor in insure that the components are functioning properly. Recommended oil feed is -3AN or -4AN line or hose/tubing with a similar ID. As always, use an oil filter that meets or exceeds the OEM specifications.