This is a very odd niche market you are considering. If you aren't talking about a whole new rack & pinion, then you must be talking about gearing the steering column itself. Unless tolerances are very tight, this will add play to the system, reducing steering precision some.
Let's consider possible customers:
Street racers - basically straight line racers
Straight line racers - why would they care?
Autocrossers - this modification would land you in a very diffucult class - SM or something similar - definitely not worth doing on its own if it kicks you out of your present class. There are only a few hundred SM Honda's in the country.
Road Racers - I'm sure that if the system were precise enough, they might appreciate it, but I don't know about their class rules.
What price point are you considering for this? How much might it cost to make this device, and what volume are you considering?