
Ball Bearing Turbocharger Upgrade
for 1999.5 – 2003 Power Stroke 7.3 Ford Trucks
F250, F350 & Excursion PowerStroke Diesel
 |
Model Years 1999.5 – 2003 7.3L PowerStroke Engine |
 |
The GTP38R Turbo |
 |
A Garrett Exclusive Ball Bearing Cartridge for Unbeatable Response, Efficiency, and Durability. Elimination of the Thrust Bearing Eliminates Failures at Elevated Boost Levels |
 |
The 88mm GT Compressor Wheel Provides 33% More Flow than the Stock 80mm Wheel. Ported Shroud Housing Improves Compressor Flow Range for Surge Control |
 |
1.00 A/R Turbine Housing for Free Flowing Exhaust with Reduced Back Pressure and up to 200° F Reduction in Exhaust Gas Temperature |
 |
Maximum Recommended Boost Level is 40psi |
|
|
Stock Turbo |
Garrett Turbo Kit |
|
HP |
210whp @ 2700rpm |
290whp @ 3000rpm* |
Torque |
420lb/ft @ 2500rpm |
550lb/ft @ 2400rpm* |
* With Performance Chip and Exhaust Upgrade |


|
Turbo Glossary- Performance
|
A/R describes a geometric property of all compressor and turbine housings. Increasing compressor A/R optimizes the performance for low boost applications. Changing turbine A/R has many effects. By going to a larger turbine A/R, the turbo comes up on boost at a higher engine speed, the flow capacity of the turbine is increased and less flow is wastegated, there is less engine backpressure, and engine volumetric efficiency is increased resulting in more overall power.
|
|
|
|
The CHRA includes a complete turbocharger minus the compressor and turbine housings. |
|
|
|
When an angle is machined on the turbine wheel exducer (outlet side), the wheel is said to be ‘clipped’. Clipping causes a minor increase in the wheel’s flow capability, however, it dramatically lowers the turbo efficiency. This reduction causes the turbo to come up on boost at a later engine speed (increased turbo lag). High performance applications should never use a clipped turbine wheel. All Garrett GT turbos use modern unclipped turbine wheels. |
|
|
|
|
The GT designation refers to Garrett’s state-of-the-art turbocharger line. All GT turbos use modern compressor and turbine aerodynamics which represent huge efficiency improvements over the old T2, T3, T3/T4, T04 products. The net result is increased durability, higher boost, and more engine power over the older product line. |
|
|
|
On-center turbine housings refer to an outdated style of turbine housing with a centered turbine inlet pad. The inlet pad is centered on the turbo’s axis of rotation instead of being tangentially located. Using an on-center housing will significantly lower the turbine’s efficiency. This results in increased turbo lag, more backpressure, lower engine volumetric efficiency, and less overall engine power. No Garrett OEM’s use on-center housings.
|
|
|
|
Trim is an area ratio used to describe both turbine and compressor wheels. Trim is calculated using the inducer and exducer diameters. As trim is increased, the wheel can support more air/gas flow. Use these formulas when calculating trim:
|
|
|
 |
|
 |
|
|
|
A wastegated turbocharger includes an integral device to limit turbo boost. This consists of a pneumatic actuator connected to a valve assembly mounted inside the turbine housing. By connecting the pneumatic actuator to boost pressure, the turbo is able to limit its maximum boost output. The net result is increased durability, quicker time to boost, and adjustability of boost. |
|