Hunter 340 Genoa upgrade?

[Cheeky Monkey]

Bought a 1996 340 2 years ago and all the rigging and sails are original with heavy use so I am replacing the sails for sure and maybe the lines. I would like to add a little more power to the boat which seems to lag in the 4-5 kts range for most sails in 10-12 knts of wind. I know max hull is about 6.5 but since I am replacing the sails will a 120% genoa work and what sort of improvements can I expect? The boat has a running track for the lines so I can pull those back to accomodate the difference in length. Anyone have any experience in this?

 

[Alan]

First, your theoretical hull speed is nearly 7.2 knots not 6.5.

The limiting factor of the rig on your boat is the location of the chainplates. They sit out on the toerail making proper sheeting of an overlapping headsail impossible. You may be able to squeeze a 120 and still sheet inside the shrouds but that is probably the limit. Your sailmaker will be able to tell you the absolute limit.

Because you have a fractional rigged boat the main driving force (the engine) is the main sail. Have your new main designed with maximum roach, loose foot, cunningham cringle and be sure to have a good vang setup. Upgrade your halyards to high modulus low stretch line that will improve sail shaping ability.

You may also want to consider an asymmetrical spinnaker for off wind sailing performance improvements.

 

[Cheeky Monkey]

Wow, that was brilliantly concise. If the theoretical hull is 7.2 then I definitely need new sails because I have never been close to that.

I was planning on replacing the halyard on the main as I think I have stretching and at the very least it isnt catching as effectively as I would like. I never feel like I have it tight.

As for the spinnaker, well, let's just say I've spent this years sail budget but I definitely would like to add one.

Thanks for the post.

 

[Todd Smith]

Do you have a clean bottom ?
Carrying a couple of thousand pounds of extra weight ?
Is the rig reasonably tuned ?

There are other reasons than sails for slow speed.

 

[RichH]

Along with what Alan suggests and if you want top performance in the lower wind ranges ...
for the jib consider a 'radial cut', cut somewhere between a 'cruising cut' and a 'flattish' racing cut ... and consider to have the panels near the luff constructed with a lighter weight material than the panels near the leech which would be a heavier weight. This will provide a better and tighter 'roll' when at reduced SA, will enable less energy to keep the important luff area 'full' when in light winds ... and when 'reefed' will only have the heavier weight panels exposed.

I'd also suggest for the jib an 'over the top' leech line control system ... so that you can easily adjust the leech tension when the sail is 'reefed' and when the clew is 'well off' the centerline ... and can be adjusted from near the furling drum/forestay (in addition to the standard leech position')

All this shouldn't increase the total cost of the sail all that much (in comparison to standard 'radial cut'), but will build a more 'versatile' and longer lasting, better performing sail over a wider wind range. Your not going to get something like this from a mail-order store.
If interested discuss in detail with your sailmaker.