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Author: Jason Cosler
Subject: IRC Rule
Info: (3942 views) Posted: Thursday 1-6-05 01:44:29 PM
You must enter a name Message not posted due to errors. Author: Subject: IRC Rule

As a PHRF racer thoroughly dissatisfied with the "rule" I've been waiting to see what an Expresses IRC rating would be. Be careful what you wish for?

The IRC rule uses time-on-time correction (i.e. you multiply your total elapsed time by the correction factor to get your corrected time - much simpler than computing time allowance and then subtracting like PHRF). So there really isn't anyway to transfer the rating to seconds per mile. We race against a J/27 and a J/29 on Tuesday's and so I did some comps on several races this year and the Express comes out on the losing end for almost the entire range of corrected times. On a race that we corrected over the J/29 by over a minute, our advantage goes to about 6 seconds with IRC (wha? we killed them that race). Similar with the J/27. In most cases with the J/27, the time they owed us was just about cut in half. I've got to believe that 0.933 is a masthead rating. The reason being that the PHRF spread between us and the J/27 is 15 sec/mile with a frac setup and 9 sec/mile with a masthead, or just about half. I'm just curious enough that I might pay the $75 or whatever just to see what Partial Magic would rate today.

Do I still support a change from PHRF? I'm inclined to say yes. At least with IRC this BS politicing about ratings would go away. That and I think their approach to one-design ratings is a good one. PHRF issued one-design ratings in order to simplify the arduous (?) task of actually writing down a boats dimensions on the application). The problem is that you're then saddled with the class one design rules and if the class decides not to remain current with technology, you suffer while all of the other non-OD rated boats are free to do so. I'm talking about something like mylar sails and spinnaker cloth weight. The Express class rules are a good example. Technically, I'm probably out of compliance with my PHRF certificate since our kite is Airx 600, which is closer to 0.50 oz than the 0.75 oz class rule which isn't even geared at a fabric like Airx, it's geared at polyester, which is rapidly being replaced these days.

I know Block Island is planning to use IRC this year, so I'll be watching that closely to see if an Express shows up. I'd be interested in hearing how things shake out in Detroit.

-Jason

:: I received the following reply to my inquiry to the
:: RORC:
::
:: "We rated one Express 27 back in 2001, her rating was
:: 0.933. Bear in mind that this was just one boat (not
:: necessarily standard) and that the ratings will have
:: altered slightly in the last 3-4 years.
::
:: "I am attaching a list of ratings (2004) for some well
:: known designs, I hope this helps."
::
::
::
:: Here are some of the ratings from the RORC list:
::
:: Laser 28-.915;
::
:: Contessa 33-.935;
::
:: Dehler 34-.940;
::
:: J27-.940;
::
:: J29-.945;
::
:: J80-.970;
::
:: J105-1.02;
::
:: Mumm 30-1.09
::
:: Anybody know how these ratings translate into seconds
:: per mile? Or how they can be equated to PHRF ratings?
::
:: I would be inclined to take issue with the relationship
:: between the E27 rating and the Laser 28 rating. My
:: impression is that the two boats are pretty close in
:: performance in typical medium air conditions.

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