With 3 cam sails, the "minimum downhaul" is going to be the point at which you have so little mast bend that the cams won't rotate.
So, nothing at all wrong with letting your 3 cam GTXs be very fat in the front (more draft = more low wind power in virtually all situations) and run the minumum outhaul also. (min. outhaul will also be the point at which you get good cam rotation.
The only issues with doing this may be batten breakage if you don't get enough downhaul and outhaul to get the cams rotating freely enough.
Most racers who run adjustable outhauls have their sails resting on the boom for lighter conditions.
This is the idea behind the wide tail booms popular with formula racers.
A wide tail boom puts more distance between the boom arms, hence you can run your big sails fuller/with more draft.
For sure give it a try and then learn how much you can "detune" your sails to get the best early planing performance.
Or, better still, get an adjustable outhaul setup and run the min downhaul. Then you get the best of both worlds.
Slack the outhaul to make the sail very full to get going in marginal conditions, then put more outhaul on to lean the sail out and give you better top speed and handling.
Hope this helps,
Last edited by Roger; 25th July 2008 at 08:43 PM.