Ball Bearing Vs. Journal Bearing....Differences
Ball Bearing Vs. Journal Bearing....Differences
07-18-2010, 05:24 PM
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you cant rebuild a BB turbo? WTF? how is that possible? I can see having to change bearings and shaft maybe. im gonna be pissed if thats the case.... say it aint so KB!!!
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07-18-2010, 05:29 PM
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I did mean plain or what Kyle said. I am no where near a guru in this field. I have just began the learning process. I am in the market for at PT76 if anyone has one.........Kyle?????
I would prefer a used one because of the budget but let me know what you have.
07-18-2010, 06:31 PM
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Advantages of Ball Bearing vs Journal bearing as per Garrett's website:
Garrett's dual ball-bearing turbos were originally designed for diesel engines. Diesels were known to produce throttle tip-in smoking. The smoke was the byproduct of a rich condition that occurs after the throttle is opened, but before boost is realized. Response was the goal because diesels don't rev very high. So ball-bearing turbos designed to spool-up quickly were developed that shortened the time between the pedal and the boost, which helped solve the problem. The highly responsive design was perfect for extreme motorsport applications, which eventually led to the HKS/Garrett GT lineup now seen on the street, as well as offerings from Turbonetics and other manufacturers.
1. Spools up to 15% faster fast faster throttle response, less tubo lag and allows a larger turbo to spool like a smaller unit.
2. Reduced Oil Flow - The ball bearing design reduces the required amount of oil to provide adequate lubrication. This lower oil volume reduces the chance for seal leakage. Also, the ball bearing is more tolerant of marginal lube conditions, and diminishes the possibility of turbocharger failure on engine shut down.
3. Improved Rotor Dynamics and Durability - The ball bearing cartridge gives better damping and control over shaft motion, allowing enhanced reliability of both everyday and extreme conditions. In addition, the opposed angular contact bearing cartridge eliminates the need for the thrust bearing, commonly a weak link in the turbo bearing system.
4. Most if not all ball bearing turbo's are water cooled which eliminates the need for a turbo timer to keep the oil trapped at the bearing from coking. I'm not sure if water cooling is an option on journal bearing turbo's so someone will have to chime in.
Generally, ball bearing turbo's are not rebuildable and require a replacement of the cartridge to re-build. The plus side is they have a 100,000+ mile life expectancy so if the time ever comes to rebuild, it's probably time to upgrade to a newer design billet compressor.
I think if you are running a large frame, single turbo on the street the issue may be pretty moot. You may find money is better spent on upgrading/dailing in your torque converter to mask the turbo lag. It seems to make a make bigger impact on smaller turbo's and twin kits. I know my throttle response with two small GT3071r turbo's is way less than a second to full boost so IMO, the ball bearing turbo's make the truck more streetable as a daily driver. Down side, it added $500-600 to the price of the kit.
On a "really doesn't matter" note, I do really like the sound of the spool down that lasts 75-120 seconds after I shut off the truck. It puts a smile on my face everytime I hear it. :-)
Rick
Garrett's dual ball-bearing turbos were originally designed for diesel engines. Diesels were known to produce throttle tip-in smoking. The smoke was the byproduct of a rich condition that occurs after the throttle is opened, but before boost is realized. Response was the goal because diesels don't rev very high. So ball-bearing turbos designed to spool-up quickly were developed that shortened the time between the pedal and the boost, which helped solve the problem. The highly responsive design was perfect for extreme motorsport applications, which eventually led to the HKS/Garrett GT lineup now seen on the street, as well as offerings from Turbonetics and other manufacturers.
1. Spools up to 15% faster fast faster throttle response, less tubo lag and allows a larger turbo to spool like a smaller unit.
2. Reduced Oil Flow - The ball bearing design reduces the required amount of oil to provide adequate lubrication. This lower oil volume reduces the chance for seal leakage. Also, the ball bearing is more tolerant of marginal lube conditions, and diminishes the possibility of turbocharger failure on engine shut down.
3. Improved Rotor Dynamics and Durability - The ball bearing cartridge gives better damping and control over shaft motion, allowing enhanced reliability of both everyday and extreme conditions. In addition, the opposed angular contact bearing cartridge eliminates the need for the thrust bearing, commonly a weak link in the turbo bearing system.
4. Most if not all ball bearing turbo's are water cooled which eliminates the need for a turbo timer to keep the oil trapped at the bearing from coking. I'm not sure if water cooling is an option on journal bearing turbo's so someone will have to chime in.
Generally, ball bearing turbo's are not rebuildable and require a replacement of the cartridge to re-build. The plus side is they have a 100,000+ mile life expectancy so if the time ever comes to rebuild, it's probably time to upgrade to a newer design billet compressor.
I think if you are running a large frame, single turbo on the street the issue may be pretty moot. You may find money is better spent on upgrading/dailing in your torque converter to mask the turbo lag. It seems to make a make bigger impact on smaller turbo's and twin kits. I know my throttle response with two small GT3071r turbo's is way less than a second to full boost so IMO, the ball bearing turbo's make the truck more streetable as a daily driver. Down side, it added $500-600 to the price of the kit.
On a "really doesn't matter" note, I do really like the sound of the spool down that lasts 75-120 seconds after I shut off the truck. It puts a smile on my face everytime I hear it. :-)
Rick
Last edited by Rick_Vor; 07-19-2010 at 02:25 PM. Reason: updated pricing difference on bb vs journal