Engine Control Components: Turbocharger: Notes
The dual boost turbocharger used on the wide frame vehicles is a 3 wheel design with a single turbine and 2 compressor wheels placed back to back. The 2 compressor wheels are similar to each other. They have the same diameter and are optimized to reduce pressure differences that could cause noise or air flow issues. The standard 2 wheel design is used on the narrow frame vehicles.
The turbocharger uses variable vanes that surround the turbine wheel to dynamically adjust turbocharger speed using exhaust gases. During engine operation at low speeds and load, the vanes are closed to accelerate exhaust gases across the turbine wheel to help quickly increase turbo wheel speed. At high speeds the vanes open to prevent turbocharger overspeed conditions.
The turbocharger uses a ball bearing cartridge that surrounds the turbocharger shaft to help provide a decrease in spool up times. Separate oil and water feeds flow through the turbo mounting pedestal to lubricate and cool the turbocharger to eliminate as many external connections as possible. The front of the pedestal houses the turbocharger oil filter.
The turbocharger provides up to approximately 206.84 kPa (30 psi) boost at up to 130, 000 RPM.