QUOTE(smj @ Jun 16 2009, 02:21 PM)
I'm picking up a variety of opinions -- shocking!
I've got an Accusump from the 944S I retired, sitting around doing nothing. I thought it might eventually be useful in a teener.
Sounds like everybody feels a Type IV benefits from an Accusump, but a 6 with a well positioned oil tank shouldn't for street applications, might for track applications.
Fair summary?
I believe my -6 will only see the track a couple times for grins, and will be setup for agressive street use. So it looks like I won't need the 'sump there, when I finally get around to cleaning it up.
The dry sump is setup for POSITIVE oiling under all conditions (assuming a correct installation). Dry sumps are used for a couple of reasons:
1.) Positive Oiling
2.) Reduction of oil volume in the case (or sump) to avoid parasitic drag of oil droplets in the rotating assembly (takes horsepower away)
Hell, Aerobatic capable planes use a dry sump system to fly upside down (at least for a few moments anyway).
Wet sump systems suffer from a couple of problems:
1.) Loss of oil pressure when the oil moves away from the oil pump pickup in hard cornering / hard acceleration or deacceleration.
2.) Parasitic drag on the rotating components of an engine robbing horsepower. That spinning crank assembly creates quite a storm over the lake of oil in the sump. Deep pans, specially modified pans with baffles, crank scrapers and windage trays were developed to overcome this horsepower robbing drag.
On a small 4 cylinder racing engine, I was once told that the dry sump system would add about 5 hp from the lack of the lake of oil ... maybe true, maybe not.
Ok, that's enough. Wanna know more ... visit a library.
Oh, an Accusump is a trade name ... the correct terminology is hydraulic accumulator ... the ones we used on the race cars were HAs from a Boeing 707 hydraulic system.