This is a must have for those building a high rpm, high horsepower Subaru. Unlike the stock stamped steel crank pulley, the Fluidampr is internally balanced and covers a much broaders spectrum of frequencies emitted from the crank during a combustion cycle. This ensures safe operation even under the most extreme conditions.
These pullies are remarkably simple, yet simultaneously ingenius. They are made of steel (the keyway section as well, ensuring zero long term issues), feature a very durable zinc finish. The pulley is filled with silicone and sealed via laser welding. The silcione and internal inertia ring covers a significantly broader range of frequencies vs the stock pulley, which has a thin, glued in external elastomer ring (which has been shown to separate, crack, and degrade as the cars age, particularly on built engines with higher than stock rev limiters).
It weighs in at 6.9 lbs, and has an outer diameter of 5 3/8". By comparison a stock pulley weighs 5.2 lbs. Yes, this weighs more. The pulley is filled with silicone and as such, it covers a significantly broader range of frequencies vs the stock pulley, which has a thin, glued in elastomer ring (which has been shown to separate, crack, and degrade as the cars age, particularly on built engines with higher than stock rev limiters).
There is no comparison to be made to the various aluminum pullies out there. Yes, aluminum weighs very little. These pullies can make the engine respond a bit faster vs the stock unit. However, they do not have any ability to balance out vibrations, which is why the natural byproduct is often check engine lights (especially when mated to a lightweight flywheel, and especially when the rev limiter has been increased) as well as noise from the accessories (since you no longer have the elastomer ring there to dampen out the accessories). Each component that makes up the pulley is zero balanced, ensuring zero machine work or modifications are needed when installing it, unlike many of the aluminum ones on the market, which if put on a balancer, reveal their true colors. While suitable for a stock engine, they can be a risk on those running built engines with higher than stock rev limiters
If you are building an engine this winter, or in the near future, this is a fantastic addition. Even with an ultra lightweight flywheel, your car will idle quieter, engage gears smoother, maintain more torque over a broader rpm spectrum vs the various aluminum pullies, and not fall apart or separate over time like the OEM pulley can.
We have these in stock, priced at $355 shipped in the 48 states. We also can provide new belts for those who need those as well