7.8 sail tuning for speed?

Sail is only one part of setup, what board -fin are you using?

More downhaul, go past the recommended downhaul max and see how you go

Thank you!
I think you're right on all counts!
flatter heavier windier!
mire downhaul makes sense, I don't understand the mechanics but if the sail can't exhaust fast enough it makes more drag?

I assume it matters where the leach releases?
I tried the lower clew to try to loosen the leach but that was slower.
more downhaul & the sail camber de-rotates/doesn't rotate fully/flattens off. Maybe there is another adjustment to counteract that?

Maybe it's the design wind range/speed if the sail?
The next sail down presumably has more release with less downhaul .

thanks again!

Post some pic's om how it's rigged

More downhaul than the recommended setting, 1-2cm as Mark suggested, also I find having slightly negative outhaul helps, again 1-2 cm and tighten the tack strap to get a bit of fullness low down and lock that power in.

Mast base position can be a massive factor in how fast you go as well so play around with that moving the mast base 1cm at a time back until you find that sweet spot. When moving it back you'll get to a point where the nose of the board is constantly getting raised in a gust and the board is harder to control, just slightly forward of the point you had it set at when that was happening is the sweet spot.

On your 107 you'll only really need the 37cm but on your 97 the 36cm is way too big and the 34cm slightly larger than I would use, a 32cm would be prefect

Another thing to try is when sailing along keep an eye upwind for gusts and get ready to bear off on one, something called a slingshot where you can use the extra wind speed of the gust and turn it into extra speed.

Don't worry once you've got your kit tuned perfect the extra speed will come

Nearly the same setup, only using a JP Slalom 71 with Z-SLM 37 S- and also 100 kg. 36 kn should easily be done for max speed. Fastest runs I get out of my setup are low to mid 38 kn with low 39 kn max speed.

Use a FLX 100 460 with a NP MXT 34 set to 20 cm extension. When downhauling the sail, sail flat on the ground without boom mounted, the loose leach should be bang on in the middle of the big NP logo near the leach. Ending right at the bottom mini batten. This should result in the loose leach being visible to about 5 to 10 cm off the luffpanel between the mast sock and sail panels.Bottom 3 battens should have plenty tension. Remove all wrinkles in the lower 3 panels and give each batten at least 1,5 turn extra. The top 5 battens (leach area) only tension just enough to remove the wrinkles in the batten pockets.For rougher water pull the tackstrap until you feel tension, for flatter water add another 2 to 3 cm extra tension to the tackstrap.Boom setup height wise, for me at 191 cm, about 10 cm from the top of the boom opening. The bottom of my boomhead is just above the midpoint of the boomopening. I use the lower clew with a boom length of 207,5. Outhaul pull to tension and add just 1 or 2 cm. When you pick up the sail and look at the sail body from the clew the body of the sail should just stay clear of the boom.

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Pipington said..
Hi
I often get stuck on 7.8 (NO Evo9) when the when the wind comes up. I seem to get stuck at 36 knots where 7.0 would have been a lot faster?
I've tried different settings. top clew, full until touching the boom at the harness lines, boom in the middle seems fastest.
An I missing something?
Is flatter possibly faster?
can 7.0 have that much better lift/drag to be 2-3 knots faster?
Thanks for any ideas/advice!

Even for a 100K sailor, getting 36 knots out of the gear that large is very good indeed. There are a few very experienced, large speed sailors at excellent venues who may go slightly faster, on that size gear, but not by much.

IMHO, you have most likely near maxed out that equipment, assuming you have got close to the ideal angle off the wind. There is definitely a point where a larger sail, and board, and fin, just create too much drag to go faster. I am a lightweight, shorty (about 73KG/175cm), and there is no way I can go anywhere near that fast on such large sails despite years of speed sailing experience and regular access to near ideal speed conditions. Generally speaking, the smaller the sail, fin and board I can get 'powered' up on, the faster I can go. Changing to the 7m sail most likely could get you an extra 2 or 3 knots of speed, compared with using the 7.8m, because:
1. You may be able to generate the same amount of power, with an efficiently rigged sail. but with less drag from the sail.
2. A lighter rig will also allow your board to 'fly' higher in the water (less drag from the hull) and
3. Enable you to use a smaller fin, which will also reduce drag.

The oft' repeated myth that you will go fastest with the largest sail you can hang onto, simply is not true in most conditions (possible exception in very gusty, up and down wind conditions). You will go fastest, at the ideal angle off the wind with the best power to drag ratio. There is only so much power you can make maximum use of according to you height and weight. Getting that much power out of the sail with the lowest drag penalty will be the fastest. If you have to over downhaul the sail and over flatten it to reduce the power so you can keep it under control, you are carring too much sail, with too much weight and drag penalty to be ideal.

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John340 said..

sailquik said..

Pipington said..
Hi
I often get stuck on 7.8 (NO Evo9) when the when the wind comes up. I seem to get stuck at 36 knots where 7.0 would have been a lot faster?
I've tried different settings. top clew, full until touching the boom at the harness lines, boom in the middle seems fastest.
An I missing something?
Is flatter possibly faster?
can 7.0 have that much better lift/drag to be 2-3 knots faster?
Thanks for any ideas/advice!

Even for a 100K sailor, getting 36 knots out of the gear that large is very good indeed. There are a few very experienced, large speed sailors at excellent venues who may go slightly faster, on that size gear, but not by much.

IMHO, you have most likely near maxed out that equipment, assuming you have got close to the ideal angle off the wind. There is definitely a point where a larger sail, and board, and fin, just create too much drag to go faster. I am a lightweight, shorty (about 73KG/175cm), and there is no way I can go anywhere near that fast on such large sails despite years of speed sailing experience and regular access to near ideal speed conditions. Generally speaking, the smaller the sail, fin and board I can get 'powered' up on, the faster I can go. Changing to the 7m sail most likely could get you an extra 2 or 3 knots of speed, compared with using the 7.8m, because:
1. You may be able to generate the same amount of power, with an efficiently rigged sail. but with less drag from the sail.
2. A lighter rig will also allow your board to 'fly' higher in the water (less drag from the hull) and
3. Enable you to use a smaller fin, which will also reduce drag.

The oft' repeated myth that you will go fastest with the largest sail you can hang onto, simply is not true in most conditions (possible exception in very gusty, up and down wind conditions). You will go fastest, at the ideal angle off the wind with the best power to drag ratio. There is only so much power you can make maximum use of according to you height and weight. Getting that much power out of the sail with the lowest drag penalty will be the fastest. If you have to over downhaul the sail and over flatten it to reduce the power so you can keep it under control, you are carring too much sail, with too much weight and drag penalty to be ideal.

Daffy,
My experience at Lake George this year was somewhat different. My best 2sec speeds for each sail size were:
- 38.5 for 7.7,
- 39.5 for 7.0
- 39.8 for 6.2
I've given some thought as to why I can sail fast on big gear but not translate that speed onto smaller gear in higher wind conditions. I think it's because I'm better at maintaining the ideal angle off the wind and board and sail trim required to maximise speed in lower wind speeds and associated mirror flat water. So I'd modify the axiom as follows:

"You go fastest with the largest sail you can use while still maintaining the ideal angle off the wind and board and sail trim needed to go fast"

What were the 10 second times?

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sheddweller said..
What were the 10 second times?

37.8 7.7
38.4 7.0
38.7 6.3

Agree, much easier to go fast with big gear in perfect conditions like Lake George. Does show what the gear is capable of and has made me more aware of keeping on the bigger gear in some of the gustier days at my local spot, as you know you still can go quick on the big gear if you get a good gust.

I'm 96kg and my best speeds with bigger gear (113L board) at LG earlier this year were:

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I 'm pretty sure someone did 41knts on an 8.2 from memory at LG

Shannon Blume

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John340 said..

sailquik said..

Pipington said..
Hi
I often get stuck on 7.8 (NO Evo9) when the when the wind comes up. I seem to get stuck at 36 knots where 7.0 would have been a lot faster?
I've tried different settings. top clew, full until touching the boom at the harness lines, boom in the middle seems fastest.
An I missing something?
Is flatter possibly faster?
can 7.0 have that much better lift/drag to be 2-3 knots faster?
Thanks for any ideas/advice!

Even for a 100K sailor, getting 36 knots out of the gear that large is very good indeed. There are a few very experienced, large speed sailors at excellent venues who may go slightly faster, on that size gear, but not by much.

IMHO, you have most likely near maxed out that equipment, assuming you have got close to the ideal angle off the wind. There is definitely a point where a larger sail, and board, and fin, just create too much drag to go faster. I am a lightweight, shorty (about 73KG/175cm), and there is no way I can go anywhere near that fast on such large sails despite years of speed sailing experience and regular access to near ideal speed conditions. Generally speaking, the smaller the sail, fin and board I can get 'powered' up on, the faster I can go. Changing to the 7m sail most likely could get you an extra 2 or 3 knots of speed, compared with using the 7.8m, because:
1. You may be able to generate the same amount of power, with an efficiently rigged sail. but with less drag from the sail.
2. A lighter rig will also allow your board to 'fly' higher in the water (less drag from the hull) and
3. Enable you to use a smaller fin, which will also reduce drag.

The oft' repeated myth that you will go fastest with the largest sail you can hang onto, simply is not true in most conditions (possible exception in very gusty, up and down wind conditions). You will go fastest, at the ideal angle off the wind with the best power to drag ratio. There is only so much power you can make maximum use of according to you height and weight. Getting that much power out of the sail with the lowest drag penalty will be the fastest. If you have to over downhaul the sail and over flatten it to reduce the power so you can keep it under control, you are carring too much sail, with too much weight and drag penalty to be ideal.

Daffy,
My experience at Lake George this year was somewhat different. My best 2sec speeds for each sail size were:
- 38.5 for 7.7,
- 39.5 for 7.0
- 39.8 for 6.2
I've given some thought as to why I can sail fast on big gear but not translate that speed onto smaller gear in higher wind conditions. I think it's because I'm better at maintaining the ideal angle off the wind and board and sail trim required to maximise speed in lower wind speeds and associated mirror flat water. So I'd modify the axiom as follows:

"You go fastest with the largest sail you can use while still maintaining the ideal angle off the wind and board and sail trim needed to go fast"

Excellent speeds John! For a sailor of your skill and experience in those idea conditions I am not surprised at all.

And I am always in Awe of Dave's (AUS04) fantastic speeds!!

Shannons 41 on an 8.2 is simply extraordinary!

Nevertheless, I think your and Daves above examples nicely support my supposition that you can ultimately go faster on smaller gear, once you have all the power you can convert, due to less drag.

I have witnessed with great respect how you guys from up North, especially Queensland, can get so much speed from larger gear. I think this is because you get so much practice in those type of conditions and have consequently refined your equipment choices, setup and technique in those conditions to a very high degree. It's not at all as common for you to get much time to refine your skills and setup on smaller gear in stronger winds.

Dave is simply, IMHO, an extraordinarily gifted sailor, who can go very fast indeed, in all wind strengths!

And I totally agree about the importance of the ideal angle off the wind, but I still maintain that too large a sail for your size/stature will come with a drag penalty, and possibly a control penalty, and limit your top speed. A larger board is not so much of a drag handicap at LG due to the extraordinarily flat water, but the basic principles still apply.

I came from a very different development background, having access to very regular 30-40 kt winds and an ideal speed course. It has taken me quite a while to learn the ideal angles for the moderate wind speed sailing at LG. I think I am getting there, but I still have a long way to go in that area.

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sailquik said..

sheddweller said..

choco said..If you're a sail maker LG would probably be one of the best spots to test race sails, no chop or anything to hindrance the evaluation of the designs.

It would be the very best place to test sails designed for LG.
Not real world testing useful for other places!

For many of us in Australia, LG type conditions ARE 'Real World'. It's not our only speed venue like this.

But I agree, for many places on the rest of the world, those conditions are very uncommon, and other design factors come into play.

At present sails are tested mainly open water, so how do they know any changes/tweaks were beneficial if they have to contend with large chop swell etc too many other variables affecting the feedback, flat water like LG would give instant feedback.

Shannon's 41.6 2 sec on 8.2 sail 120 board