Greddy or blitz

[Blown_xa]

There are good and bad points of each kit.

The Blitz is a Roots type design and makes an awesome sound.
This supercharger pulley is clutch driven and is has a switch for engagement at different throttle positions, or off. I never liked the feature myself though, and never saw gas mileage benifits of turning it off probably because of the restriction of the roots blades. The Roots blades are also made of a composite material I believe, which will withstand water methenol injection. The supercharger is driven by a longer than factory 4pk wide belt.

The Greddy supercharger kit is a screw type supercharger (Magnacore).
I like the fact it comes with an emanage. I like the fact that it is driven by a 6pk belt piggy backed off the alternator. I don't like the fact that the supercharger blades are teflon coated and have been known to delaminate if you ever choose to add water methanol injection.
I don't know if this kit would fit the Yaris, as the supercharger unit is larger and modification may be required to the hood and core support.