J/99 anyone have info beyond the teaser?
- Thread starter AndreasE
- Start date
Fastrak
Member
Gybe angles at 174-177 TWA in 14-29 TWS ?????? Really?????? Or am I not understanding how ORC works (being an IRC man)??
ORC does the same thing to many asym boats... unrealistic downwind angles.
ORR is pretty bad too
Some of the models are a bit flawed, and VPP needs to be calibrated. Typically I add 4% to most speed figures and adjust VMG angles downwind. Curves are pretty "flat" downwind so basically you just dial down the angles beyond the "real" TWA. I would guess the J/99 starts at 135 in light air and ends up at TWA 160 in TWS 16-18, then planing at TWA 150 until things explode :lol:
IRC, ORC, ORR and all other rules are flawed in different ways, but ORC does a decent job when you try to compare similar boats (like the two boats above).
Looks worse than it is, as the VPP undersetimates speed at real target TWA B)
ORC actually rates J/boats pretty fair. The J/112e won the last Worlds (as one of very few sprit boats), J/99 just won ORCi overall in RSYR, J/122e have been winning big races in Holland and we've posted some solid results with the J/111 both in Scaninavia and in the Med (ORC class wins in all races so far).
Our experience is that ORC can handle both our turbo config (with 155 m2 whopper, Jib 0 and a 50% code) as well as our more dialled down IRC mode.
i don't disagree - i was just commenting on the issue with the VPP and downwind angles.
i race on a boat with an asym and we do very well under ORC
if, for example, you want to use the ORC numbers as polars for routing in expedition, you should change the angles - even a guestimate is better than just using them out of the box.
mostly the issue is only with the numbers at higher wind speeds. the other numbers are more reasonable.
GHarring19
New member
Major Congratulations to Disko Trooper - so awesome to see a 99 with a massive win!!! It looks like there was a lot of breezy reaching involved, and the 99 for sure loves those conditions - well done Gentlemen!!!
Roleur
Super Anarchist
So 3 main differences.
Disko's main is 10% smaller.
Disko's jib is about 3% bigger.
Rum has a flying jib.
Sounds to me the flying jib was a rather big rating hit. Which might have been justified if they had a reachy year, but for this year, the smaller main on Disko was probably an advantage straight up, forget the rating advantage.
Disko actually mentioned they picked the J/99 because is was a good boat (rates well?) for up/down races, but no so good reaching.
I also heard Disko mention they carried a J4 and J5. I've never heard of a J5 for boats this size, but I suppose when you make sailcloth and are planning for a Sydney Hobart why wouldn't you have a J5?!
Roleur
Super Anarchist
Two thoughts...
1. The ORC downwind VPP numbers are crap - it has, for example forecast optimum VMG run TWA of 180 for some poled boats. And the J would be unlikely to ever sail deeper than 155 TWA.
2. For Hobart, shorthanded, you would have a 1, small reef to #3; off at around 23 TWS, 1 reef in main, then a 4/5 and a carbon sail about 2/3 the size of a max area storm jib, set on a stay.... and a three reef main.
1. The ORC downwind VPP numbers are crap - it has, for example forecast optimum VMG run TWA of 180 for some poled boats. And the J would be unlikely to ever sail deeper than 155 TWA.
2. For Hobart, shorthanded, you would have a 1, small reef to #3; off at around 23 TWS, 1 reef in main, then a 4/5 and a carbon sail about 2/3 the size of a max area storm jib, set on a stay.... and a three reef main.
I guess we're doing it wrong with target TWA of 158 at 14 kts and 160 at 16?
But we only put 10 years into it.
The ORC consists of a number of THEORETICAL models that ASSUMES perfect sail shapes for EVERY ANGLE and tries to approximate performance in boats from 20 to 200'. It's hard to nail the exact sweetspot VMG downwind, and that's not what you use the polars for.
If you just look at the actual VMG number, it's pretty close to the real number (just at TWA 155 instead of TWA 175). But that doesn't really matter for rating or routing purposes.
Roleur
Super Anarchist
To be fair, Blur has a much longer sprit and higher boat speeds, so it would seem that the best TWA for the J/99 should be smaller than the J/111, no?
Varan
Super Anarchist
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Black Jack
Super Anarchist
J Boats writes an article about how their new boat is great. Sure would be nice if there was knowledgeable, independent and critical journalism in Sail-World rather than advertisers writing their own copy or paying insider social media influencers to hype what should stand on their own merit.
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The "fully powered soaking angles" have been pretty similar on both J/109 and J/111, and also sailing the J/99 Calypso. Even the J/70 end up at TWA 160+. Biggest difference between designs are when wou're in stable soaking mode and when you start planing.
Speed difference between soaking J/99 and J/111 are just 10%, and as you're 20-25 degrees off dead downwind, sprit lenght makes little difference. A few degrees difference in TWA maybe?
Looking at this sequence from SH it behaves very similar to the J/111 (but needs a few more knots of wind to plane). We see "full-on plane" at TWA 150, and the "soaking mode in the lulls" at TWA 155-160.
Or maybe the boat really is great. The performance of the two J99s in the SH was impressive.
Your posts (here and elsewhere) are usually down on the costs of the sport but compared to most of the SH programs, the J99 guys did it pretty affordably. Stock boats, paneled sails in Disko's case, etc.
As an aside, I sold my J Boat for 88% of what I paid for it 16 years previously*. You know how much I raced it, and where. I think that's a great value compared to what I would have spent on other equipment-heavy pastimes.
* I sold it in 2018 (pre-Covid boat market). I probably could have gotten 100% or more today.
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To be fair, the article is attributed to J-Boats in the by-line, so no attempt to pretend…
and let’s be honest, and I say this as a “J boat” fan, one of the reasons for their success is they do a great job of “advertising” the success and performance of their boats…
Black Jack
Super Anarchist
No doubt great boats that really make sense. The J99 that sail near me in Alameda is very cool and is a witch on points of sail. Would love to catch a ride on one soon. It is my hope to charter one in France this summer for a weekend or more.
Your old J boat was pretty sweet too. I am sure the new owners are thrilled to have her. Covid has made things interesting through out the entire boat market as those who can afford a new or good boat have done well throughout it - I am quite certain that the boat I bought in early 2019 I could sell now for twice what I paid.
My point is that press releases are often seen as informative news. I like my news to come from more independent sources. That is why I like this forum because much of what we read here comes from differing view points.
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Too true! Ironically it’s these very same forums that is killing off sailing journals, and hence real journalists, as news and information travels faster via the forum than waiting for the magazine to be published…
