zef
Drag Racing Champion
I wanted to update this thread to discuss accumulators, what I have learned, and why they're important specifically for our platform when taking them to the track.
First off, what is an accumulator?
"The Accusump is the original automotive oil accumulator. It is a cylinder shaped aluminum storage container that acts as a reservoir of pressurized oil, to be released when there is a drop in the oil pressure. The Accusump is connected to the pressure side of an engine's oiling system and is charged by the engines own oil pump. Its simple, efficient design revolves around a hydraulic piston separating an air pre-charge side and an oil reservoir side. On the oil side of the Accusump it has an outlet that goes into the engine's oiling system, controlled by a valve. On the air side it's equipped with a pressure gauge(on oil accumulators only) and a schrader air valve, which allows you to add a pre-charge of air pressure to the Accusump.
Accusumps Oil Accumulators are designed collect pressurized oil from your engine and store it so it may be discharged later. At the time the engine is shut off and the Accusump valve closes any oil pressure in the Accusump is held there. On engine start-up when the valve on the oil side is opened the pressurized oil is released into the engine and therefore pre-lubricates the engine prior to start-up.
After the engine is started and the oil pump has taken over, oil is pumped back into the Accusump. This moves the piston back and pressurizes the Accusump until it equalizes with engine's oil pressure. While driving, if the engine's oil pressure is interrupted for any reason, the Accusump releases its oil reserve again, keeping the engine lubricated until the engine's oil pressure comes back to normal. This release of oil could last from 15 to 60 seconds, depending on the size and speed of the engine. In racing or hard driving conditions, the Accusump will automatically fill and discharge when needed as you corner, accelerate and brake."
Why is this important for our platform?
The TSI has documented issues of oil starvation under hard cornering. Oil essentially sloshes to one side of the oil pan away from the pick up tube, causing a drop in oil pressure, which can cause engine damage.
Not every MK6 will suffer this--many of us track without them without much issue. However, once R compounds, bigger turbos, and stiffer suspension setups are put into play, it becomes much more of a probability.
It also depends on the track. Tracks with long sweeping corners (Thompson Speedway, for example) are more likely to cause this to occur even on street tires.
What can be done about this?
As mentioned before, there are some great benefits to the accumulator. They can pre-oil your engine prior to start up, reducing "cold start" wear on the engine internals. But one thing to note is that if you choose to build out your own kit, the accumulator can only be "armed" while driving. If you leave the accumulator on all the time, when you come to a stop light, your oil pressure naturally drops to a low level due to the low load on the motor. However, once the oil pressure drops below the determined threshold (based on the pressure switch of your choosing), the accumulator will start dumping oil into your oil pan, which can overfill your engine, causing the crankshaft to "aerate" the oil, reducing its lubricating properties.
The alternative is to get your hands on APR's OPS System, which is essentially an accumulator with a built in module that communicates to the accumulator when to "arm" and "disarm" based on RPM.
Note that the APR OPS kit uses a 37 PSI pressure switch. If you are choosing to put together your own kit, I'd recommend using this as a start point for your own setup.
I will continue to update this post as I learn more.
First off, what is an accumulator?
"The Accusump is the original automotive oil accumulator. It is a cylinder shaped aluminum storage container that acts as a reservoir of pressurized oil, to be released when there is a drop in the oil pressure. The Accusump is connected to the pressure side of an engine's oiling system and is charged by the engines own oil pump. Its simple, efficient design revolves around a hydraulic piston separating an air pre-charge side and an oil reservoir side. On the oil side of the Accusump it has an outlet that goes into the engine's oiling system, controlled by a valve. On the air side it's equipped with a pressure gauge(on oil accumulators only) and a schrader air valve, which allows you to add a pre-charge of air pressure to the Accusump.
Accusumps Oil Accumulators are designed collect pressurized oil from your engine and store it so it may be discharged later. At the time the engine is shut off and the Accusump valve closes any oil pressure in the Accusump is held there. On engine start-up when the valve on the oil side is opened the pressurized oil is released into the engine and therefore pre-lubricates the engine prior to start-up.
After the engine is started and the oil pump has taken over, oil is pumped back into the Accusump. This moves the piston back and pressurizes the Accusump until it equalizes with engine's oil pressure. While driving, if the engine's oil pressure is interrupted for any reason, the Accusump releases its oil reserve again, keeping the engine lubricated until the engine's oil pressure comes back to normal. This release of oil could last from 15 to 60 seconds, depending on the size and speed of the engine. In racing or hard driving conditions, the Accusump will automatically fill and discharge when needed as you corner, accelerate and brake."
Why is this important for our platform?
The TSI has documented issues of oil starvation under hard cornering. Oil essentially sloshes to one side of the oil pan away from the pick up tube, causing a drop in oil pressure, which can cause engine damage.
Not every MK6 will suffer this--many of us track without them without much issue. However, once R compounds, bigger turbos, and stiffer suspension setups are put into play, it becomes much more of a probability.
It also depends on the track. Tracks with long sweeping corners (Thompson Speedway, for example) are more likely to cause this to occur even on street tires.
What can be done about this?
As mentioned before, there are some great benefits to the accumulator. They can pre-oil your engine prior to start up, reducing "cold start" wear on the engine internals. But one thing to note is that if you choose to build out your own kit, the accumulator can only be "armed" while driving. If you leave the accumulator on all the time, when you come to a stop light, your oil pressure naturally drops to a low level due to the low load on the motor. However, once the oil pressure drops below the determined threshold (based on the pressure switch of your choosing), the accumulator will start dumping oil into your oil pan, which can overfill your engine, causing the crankshaft to "aerate" the oil, reducing its lubricating properties.
The alternative is to get your hands on APR's OPS System, which is essentially an accumulator with a built in module that communicates to the accumulator when to "arm" and "disarm" based on RPM.
Note that the APR OPS kit uses a 37 PSI pressure switch. If you are choosing to put together your own kit, I'd recommend using this as a start point for your own setup.
I will continue to update this post as I learn more.
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