New oversize kite for J/111

[George Dewey]

I have seen @Blur and others here talk about using an oversized kits on the J/111 for more speed (fun), but as I search I can't find the right thread. I currently have an A1.5, A2 and an A3, all class legal, and I'm thinking my inventory could benefit from a bigger asym. I'm sailing mostly in Charleston, SC and we're not seeing San Fran type winds, although it's not super light either. What would you guys suggest as a good sweet spot for more speed in medium winds vs PHRF hit?

 

[Roleur]

I have seen @Blur and others here talk about using an oversized kits on the J/111 for more speed (fun), but as I search I can't find the right thread. I currently have an A1.5, A2 and an A3, all class legal, and I'm thinking my inventory could benefit from a bigger asym. I'm sailing mostly in Charleston, SC and we're not seeing San Fran type winds, although it's not super light either. What would you guys suggest as a good sweet spot for more speed in medium winds vs PHRF hit?

The PHRF hit will depend on the region.  In the PNW we all run kites that are around 143sqm, versus 130sqm.  That is only a 3 sec/mile hit, so well worth it in our often light air venue.  In our region going any bigger nets a 6 sec/mile hit.  

You'll have to check your local PHRF rules to see how they address oversized spinnakers.  Up here it is very clear and you can build a kite down the square meter and know exactly what your rating will be, before building it.  

 

[George Dewey]

Thanks @Roleur Here the PHRF rules are not so clear. I emailed our handicapper what the change would be and he replied. Its keyed to ORC, which I know very little about.

If you wish to go larger or smaller than one design spinnaker size, your rating will be adjusted by the change that it makes on the “all purpose ORC rating”. ORC is not perfect, but is very good at modeling what a change in sail size makes to a conventional keel boat. Much better than typical PHRF procedure of 3 or 6 sec for every 10 % midgirth etc.

If you do not have an ORC certificate yet, it is easy to run a test certificate to see what difference the change would make for a few dollars.

 

[Roleur]

Hold that thought. I am planning to run the test certificates for both sizes mentioned above. Trying to decide on kites for a specific race with a unique rating for that race only. 

 

[Roleur]

Actually this might be easier than that. Go to the ORC database and look at the J/111 ratings. Find two boats that are very similar except kite size. Compare ratings. 

 

[George Dewey]

Actually this might be easier than that. Go to the ORC database and look at the J/111 ratings. Find two boats that are very similar except kite size. Compare ratings. 

Okay but... How does an ORC rating translate to a PHRF rating? 

 

[Roleur]

One of the ORC numbers provides a seconds/mile difference between ratings.  It used to be GPH.  I forget what they are calling it this year.  Something new.

 

[Roleur]

That didn't end up working.  The only J/111 in the ORC database with a big kite is our local boat and that is a Club certificate.  The weights of the boats vary so much, it is hard to compare.  

Very interesting that the ORC ratings for the boats that raced in the last Worlds are have about a 12 sec/mile spread.  I didn't look closely, but seems to be entirely due to weight.  As best I can tell some of boats sail at minimum class weight, but my suspicion is you can't get to minimum weight without some extraordinary mods/removals.  

 

[George Dewey]

That didn't end up working.  The only J/111 in the ORC database with a big kite is our local boat and that is a Club certificate.  The weights of the boats vary so much, it is hard to compare.  

Very interesting that the ORC ratings for the boats that raced in the last Worlds are have about a 12 sec/mile spread.  I didn't look closely, but seems to be entirely due to weight.  As best I can tell some of boats sail at minimum class weight, but my suspicion is you can't get to minimum weight without some extraordinary mods/removals.  

Well Dobbs Davis told me:

As you investigate you will see all these J/111’s have slightly different ratings because:

- measured sail sizes are slightly different

- crew weights entered may also be slightly different

- the boats themselves vary in weight - by up to 100 kg, possibly more

A variance of 220 pounds boat to boat surprises me, and makes me wonder if the measured boats are really completely stripped of stuff. That would make a difference in one design as well as handicap, obviously.

Dobbs and I were discussing this because I was looking at getting an ORC cert for Charleston Race Week. Today I decided against that. It would cost at least $750, and worse be a major pain in the ass to get the boat stripped down and moved to the measurement site. Plus the scratch sheet only has about 4 or 5 ORC boats registered across 4 different ORC classes. 

As far as what can come off? Well I guess the floor boards could be made of carbon, the door to the head is heavy and in the way. There is the whole nav table. There are wooden covers on the bunks. My boat also has pipe berths on both sides above the standard bunks. I did add an 18 pound compressor to convert the ice box to a fridge, gotta keep the beer cold for the crew!

I really have no idea what my boat weighs though. It's a 2011 so I would expect it to be heavy. Also, I'll bet France built boats are very different than Rhode Island built boats.

 

[Roleur]

I see 300kg difference in measured weight. Interestingly Blur is one of the heaviest ORCi boats and it was built in France. 

Some boats have a fridge, hot water tank, pressure water, and a table. Some have none of those things. 

Our boat is getting measured for ORCi in a few weeks. Very interested to find out the weight. 

 

[Blur]

My advice here, having "optimized" for IRC, ORCi, ORC Club, SRS (Sweden), DH (Denmark), and analyzing ORR-numbers... (I should probably get a life).

The standard OD configuration is probably pretty close to optimal. Some rules might penalize the long sprit and the big roach on the OD main. But no biggies, and pretty fair in my opinion.

Going for an oversized "whomper" A2 or any of flatter codes (mid-girth between 50% and 75%) will cost on rating, and you need to be sure that you reap the benefits. So it comes down to the specific race area or conditions in a specific race.

The rationale behind the 155 m2 A2 was: summer breeze in Scandinavia is generally very light, ie sail area is always nice. But more importantly, the sea breeze is 16-18 knots, so with the whomper, we could get on a plane in the typical sea breeze. That added a few knots and made it worthwhile.

If your only concern is the really light stuff, I'd consider a full-size flatter/lighter A1.5 or A3. Better VMG <6 knots and less hit on any rating.

 

[Blur]

I see 300kg difference in measured weight. Interestingly Blur is one of the heaviest ORCi boats and it was built in France. 

Did some research into IRC numbers a few years back, and here are the weights. Mainly Euro boats. Lightest are the inshore UK boats Journey Maker and Black Dog . Blur is pretty much on par with the other offshore boats and the benchmark J Lance at 4409 (raced by Didier who runs J/Composites in France).

• IRC is emty boat in crane = 4460 kg.
  
• ORC is emty boat, floatation test in water = 4420 kg.
  

 

[Boomerang]

I have a used oversized Quantum A1.5 and A2 that I would like to sell.  The A2 is about 162sq M.  I think the A1.5 is slightly smaller.  I sail in Hawaii and don’t need or use oversized kites.