Hey there,

New Irwin main, others I hear seem to get extra height, I cannot even match 16sq / 5.8's & others I race against.
Would love some ideas as to what to try to improve my angles.

Have played with rake, downhaul, outhaul, rotation, sheeting.
Maybe I need to rake more? batten tension? Prebend?
Centreboard / rudder angle / positions?

Seem to have trouble getting tell tales to fly especially bottom set.

Any suggestions would be welcome.....except a new boat or driver.......

Will add some pics, may help someone wiser with a suggestion?

Another pic as well.

Hi Drew,

Some great images.

If you are having trouble getting the lower leach telltales to fly then I suspect your foot is too loose. Your last image seems to confirm this.

The Irwin sail is very sensitive to foot tension. I have my outhaul fully tensioned then just backed off a little for the upwind work so it doesn't flap against the boom. It will definitely improve the airflow and will prevent it from being too powerful.

As for the Nacra 16sq, it is probably very difficult to match for upwind pointing. The lack of a boom seems to have a major effect.

Regards,

Peter

Is the goal to make the telltales fly or to point? Point until the speed drops off then sail it on the "peak speed" just before the speed drops.
I would be concerned if I couldn't point as high as other Mozzies, comparing yourself to other classes when their mast is metres longer then the Mozz and their centre of effort is much higher is not really a fair comparison. they fly a hull earlier then they pinch. How do you go against them in 15knots of breeze?.
If you can get hold of a Tactic I find them very useful for finding the settings on a new sail, only need it for a couple of sails so borrow if you can. My new Irwin is tacking through 86degrees but can go higher if necessary.

My settings are, mast just slightly aft of vertical (o.5 degree) referenced to top of the front beam, rotation pointed to the outer rear beam attach, downhaul cranked to get rid of most of the wrinkles, outhaul set to 10 cm of depth, traveller centred, diamonds set to 20mm forward of a ruler across the back of the mast.

I have noticed other boats have some variations on these settings, at 90kg I am trying to make the boat as powerful as possible. Lighter sailers would set their boats up a bit differently.

good pics by the way,
Darryn Bullet
1782

The pics I owe hugely to Paul, one of our sailors who was on start / safety boat duty, he chased us around and got plenty of pics that day. He should consider a career.

Thanks for suggestions, good to be able to get others points of view.

Will try the outhaul and Darryn's comments as a start.

I guess I am just trying to ensure I am getting best angles I can, understand I may not achieve same angle as others in our fleet but do not have any other mossie to sail against...... anyone want to come up for a visit?

In last races it appeared my upwind was where I lost more ground on the 16sq, downwind I could gain over half a leg. But net result was slipping further behind.

Was aiming for telltales to fly, would have thought indicates good flow, maybe I have wrong concept, using it as a guide to sail setting, trying to balance to maximise speed and angle.

Will do some angles from my GPS, we have quite a tidal current sometimes, will have to look at figures as sometinmes it appears we go backwards on one tack....

Will take a look at setup next racing in 10 days, gives me some places to look at, thanks so much.

What about Main sheet tension? It can be the forgotten factor, if these are boats you used to point with, perhaps the more powerfull sail is stopping you from pulling in the main as hard

I know my mainsheet loads are very high, (often pull the last bit in with my foot), but they can only be achieved, by depowering the sail. I couldn't possibly pull the main in as hard as I do, which gives plenty of leech tension, with out depowering first I would just blow over.

Generally with the Irwin sail I only use the power down wind, flatten the sail upwind. In the pictured conditions, it looks like you have more power than you need. Different crew weights make a difference, but the basis is the same, flatten sail to the point where you are not overpowered in the average conditions upwind and then sail up to spill a bit in the stronger patches (only dump sheet if you have to)and down in the lulls to keep hull flying and maximum speed.

Remember most of your height comes from keeping the speed on, but you should allways have some of the windward tell tales starting to break and continualy touching it up until it slows down, then back down again. This should be a smooth process although it doesn't sound it here, when you get the feel you actualy adjust before there is any real change in speed, you can just feel the pressure change in the rig.

Hope that helps