kingyy
15-10-2007, 07:44 PM
Why where turbo timers invented:
Many years ago when turbo chargers where invented, they where not as refined, balanced or efficient as today's turbocharger units, and when spooled up, the oil-coated brush-bearing units would get almost white-hot with very little effort required.
Now while the engine is running, the oil will spend only a limited amount of time on this white-hot metal, before boiling, foaming, and flowing away down the drop-pipe and back to the sump to cool again before starting the flow again.
Now imagine for a minute, you go for a little drive, accelerate off the lights a few times and spool up hard, get to the shops and just shut the engine down.
The mechanical oil pump stops, the oil flow stops, the oil that is sitting on the tubocharger bearings boild, but very quickly burns (much like leaving 2 minute noodles on the stove). Now think about how hard it is to clean the burn black crap off the bottom of the pot with the burnt noodles, and imagine this as a sandy sort of feel, this is what will eat and grind your turbochargers bearings out, much like sand paper.
The reason why Turbo timers are not 'realy' required today:
These days turbochargers have become very refined, balanced, and some of the newer charger units use different bearing systems than the old style brush-bearings.
These days, some cars also come with electronic oil pumps secondary to the mechanical pumps, therefore when a driver shuts the engine down after driving, the oil is still actually flowing through the turbocharger unit, therefore heating up, but flowing away before baking and causing a sandy substance to remain.
There are still new turbocharged cars with brush style bearing systems, but due to the refined engineering going into turbochargers, they dont heat up as fast, and also due to the developments in oils, they dont boil as readily, thus not as greater need for turbotimers.
Turbocharger bearings:
Brush bearings: Brush bearings are a style of bearing that is much like a solid piece of metal, but has a flow of oil across it. The bearing it's self doesn't roll or move, but has a very thin coating of oil that provides the lubrication and 'movement' of the item.
With regards to turbochargers, the spindal actually floats and spins on a fine film of oil, and the oil sits on the bearing, and the bearing floats on a fine film of oil on the bearing case.
This style of bearing system works very efficiently, and provides a lot of strength against movement, but is slow to spool up as it relys on good flow of oil. It also means that if you get a minor blockage, the bearing becomes dry and non-efficient, causing damage very quickly.
Ball/Roller Bearings: Ball Bearing turbo chargers use balls that come into contact with the turbocharger shaft and charger casing, using flowing oil to lubricate and keep the temperature down.
Ball bearings dont require as much oil as brush-bearings, but they do get hotter. Having said that, they also allow a turbhcarger to spin to the optimal boosting spool speed about 17 - 28% faster than the equivilant turbpocharger with brush-style bearings fitted.
hope you find this very intresting......
i work in the automotive trade and i am always coming across little tips like this....
very intresting read
my mate BRIAN from carfussion wrote this up... refer to this link
http://www.carfussion.com/viewtopic.php?t=535
Many years ago when turbo chargers where invented, they where not as refined, balanced or efficient as today's turbocharger units, and when spooled up, the oil-coated brush-bearing units would get almost white-hot with very little effort required.
Now while the engine is running, the oil will spend only a limited amount of time on this white-hot metal, before boiling, foaming, and flowing away down the drop-pipe and back to the sump to cool again before starting the flow again.
Now imagine for a minute, you go for a little drive, accelerate off the lights a few times and spool up hard, get to the shops and just shut the engine down.
The mechanical oil pump stops, the oil flow stops, the oil that is sitting on the tubocharger bearings boild, but very quickly burns (much like leaving 2 minute noodles on the stove). Now think about how hard it is to clean the burn black crap off the bottom of the pot with the burnt noodles, and imagine this as a sandy sort of feel, this is what will eat and grind your turbochargers bearings out, much like sand paper.
The reason why Turbo timers are not 'realy' required today:
These days turbochargers have become very refined, balanced, and some of the newer charger units use different bearing systems than the old style brush-bearings.
These days, some cars also come with electronic oil pumps secondary to the mechanical pumps, therefore when a driver shuts the engine down after driving, the oil is still actually flowing through the turbocharger unit, therefore heating up, but flowing away before baking and causing a sandy substance to remain.
There are still new turbocharged cars with brush style bearing systems, but due to the refined engineering going into turbochargers, they dont heat up as fast, and also due to the developments in oils, they dont boil as readily, thus not as greater need for turbotimers.
Turbocharger bearings:
Brush bearings: Brush bearings are a style of bearing that is much like a solid piece of metal, but has a flow of oil across it. The bearing it's self doesn't roll or move, but has a very thin coating of oil that provides the lubrication and 'movement' of the item.
With regards to turbochargers, the spindal actually floats and spins on a fine film of oil, and the oil sits on the bearing, and the bearing floats on a fine film of oil on the bearing case.
This style of bearing system works very efficiently, and provides a lot of strength against movement, but is slow to spool up as it relys on good flow of oil. It also means that if you get a minor blockage, the bearing becomes dry and non-efficient, causing damage very quickly.
Ball/Roller Bearings: Ball Bearing turbo chargers use balls that come into contact with the turbocharger shaft and charger casing, using flowing oil to lubricate and keep the temperature down.
Ball bearings dont require as much oil as brush-bearings, but they do get hotter. Having said that, they also allow a turbhcarger to spin to the optimal boosting spool speed about 17 - 28% faster than the equivilant turbpocharger with brush-style bearings fitted.
hope you find this very intresting......
i work in the automotive trade and i am always coming across little tips like this....
very intresting read
my mate BRIAN from carfussion wrote this up... refer to this link
http://www.carfussion.com/viewtopic.php?t=535