Ball Bearing Turbos: Applied on STS Advanced
- Reduced Friction: Those tiny balls significantly reduce friction between the shaft and the housing. This allows the turbine wheel to spin more freely, especially at lower speeds.
- Faster Spool-up: Less friction means quicker response! You'll notice the boost building earlier in the RPM range, leading to improved acceleration and a more responsive driving experience.
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Higher Efficiency at Low Speeds: Ball bearings excel at lower speeds where oil pressure in a journal bearing system might not be fully established.
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Ideal for:
Daily drivers who want sharper throttle response. - Applications where low-end torque and quick boost are prioritized.
Journal (aka Bush) Bearing Turbos: Applied on STD/STS/STS55
- Robust and Durable: The oil film acts as a strong cushion, making journal bearings highly resistant to wear and tear, even under high boost and extreme temperatures.
- Cost-Effective: Generally, journal bearing turbos are more affordable than their ball bearing counterparts.
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Higher Efficiency at High Speeds: As oil pressure increases with RPM, the oil film in a journal bearing provides excellent stability and efficiency at higher speeds.The following source is from Garrett - Advancing Motion
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Ideal for:
High-performance applications where durability is paramount. - Motorsport or racing where the turbocharger is consistently pushed to its limits.
- Situations where budget is a major consideration.
Beyond the Basics:
- Oil Quality is Crucial: High-quality oil and regular oil changes are essential for longevity and performance for both types of bearings, but especially journal bearings.
- Hybrid Bearings: Some turbochargers utilize a hybrid design, combining ball bearing and journal bearing technology elements to leverage each advantage.