Actually, looking up the specs of the oem unit again, and it is 2.1:1, which is the same as our standard Helical and the Quaife. The main reason to purchase an aftermarket over the oem type-r is for reliability under power, otherwise, the oem type-r is perfectly fine.
Our racepack upgrade changes the bias ratio to 2.5:1
Kozy: The main reason for quoting in % is because this is what the customer is familiar/comfortable with. If we quote ratios, most customers won't have a clue what it means. It's the same with power ratings for our gears. In real terms, quoting in hp means nothing, as it's torque that the ratings should go by, but most customers are more familiar with the "industry standard" hp ratings.