Sleeves prevent the rubber from burning since it'll be in contact with the hot engine.
The Vent to atmosphere helps release some of the crankcase pressure, similar to the breather caps. It's not too big am issue on stock turbo but hybrids and big turbos can benefit from the release of excess pressure.
The Vent to atmosphere helps release some of the crankcase pressure, similar to the breather caps. It's not too big am issue on stock turbo but hybrids and big turbos can benefit from the release of excess pressure.