Tacking Performance

[Tim F]

Hello fellow CP sailors.

I had my CP16-3 out on Saturday in some sporty (to me) conditions. 12-15 kts, occasion gusts to 20, 2 ft waves. My wife and I had a great time and were able hold at basically hull speed (5+) for some pretty long stretches.

Our tacking performance has me a little confused though. We were flying a new full bat main and an old jib of approximately 100-110% size. We'd initiate a tack from a close hauled course while making good boat speed and the boat would come across the wind quickly. However each tack would result in the boat over tacking to about a beam reach and then settling back gradually to more close hauled course. We tried adjusting the sail balance and the timing on releasing the jib (backwinding it more vs. less) but got the same behavior pretty much every time.

I've already got the idasailor rudder so no need to recommend that.

Any advice on what variables to try out?

Fore/Aft boat balance? - Two adults in the cockpit and not much weight up front (no battery). The cockpit remained dry so I know the stern could not have been too low.
Mast rake? - I aimed for a vertical to slightly forward rake and since we are able to hold a course with only slight weather helm I think I got it about right.

After reading the archives I'm assuming this just a function of the boat design and our boats just don't want to tack through 90 degrees.

Thanks for any advice.

-Tim F.
Sailing in beautiful Bellingham Bay, North Puget Sound.

[jpfx]

maybe you're losing steerage way on the tack. Keeping speed up would improve this but how exactly I'm not sure.
Wider turn on tack should keep speed up but to be honest tacking through 90 degrees with a CP16 is expecting a lot, I couldn't do it myself, maybe 120 degrees if I was really lucky.

[kickingbug1]

 two things: first the jib. i too have a new mainsail and an old jib. and occasionally have the same tacking problem. i think that  a new crisp jib would help the both of us. second is weight distribution. a friend of mine and a great sailor said that the key to speed in a com-pac 16 is to keep your weight forward. i tend to believe him as i have never been able to catch the guy. those in the know can guess of whom i speak

[KPL]

How are you executing the tack?  Are you throwing the rudder way over?  Or are you easing it over and letting the jib backwind just to start pushing the bow, but then quickly bringing it home on the new tack?

I found that if I try to tack to quickly in an effort to keep boat speed, I actually overshoot the next tack by a lot.  A slow, steady turn works much better for me.

[Salty19]

With the foiled rudder, you don't need to backwind the jib.  It will make it oversteer during tacks.  been there, done that.

Try it, I think it will solve your problem.

[philb Junkie19]

Tacking when the wind is up, particularly with a reefed main and 110% jib, my 16 II wants to bear off if I cleat the jib in right away.  I briefly let it run a little free and then adjust it in as I head off the new tack head. I think this is due to forward mast rake and an original 1986 jib putting the center of pressure forward of the ideal.

[Tim F]

Thanks for the advice everyone!

-Tim

[Bob23]

Salty:
  Oversteer? I thought only VW's and Porsche's did that. I guess I still backwind my jib a bit out of habit...certainly you are right and it's not neccesary with the new sails and foiled rudder. Although the 23's don't turn on a dime and current and wind speed play a part in how fast she tacks through.
Bob23

[Salty19]

Bob:  God love 'em for oversteer.  Steering with the throttle is an every day event around the traffic circles in the Miata.  Pretty well balanced though, not like the old MR2 that would slip her back end every chance she could.  'Course 275hp in a 2800lb car known for snap oversteer will do that  

All great advice here, and in the other current thread talking about this too.  Billy made a point that should be repeated..more jib or less main gives less weather helm. More main/less jib more weather helm.

Gotta say, if anyone is on the fence about the foiled rudder...do it...you'll look back and ask "How did I ever sail without it?!" It's really that good.
Homemade for around $50 or buy one from IDA. NACA0012 for better top speed/less drag, NACA0014 for better response at lower speeds. Almost splitting hairs between them, the IDA choose NACA 0012 because of testing performed with help from this sites' owner and chief bottlewasher, CaptnK. Either work great on Com-pacs.

[B.Hart]

Hi salty, funny to see talk about high performance mr2's on a sailing site. We built a 1991 mr2 for my son (jdm 3gse, suspension, etc) then he totals my wifes 2001 spider by spining out on a wet road and hitting a pickup head on going backward, luckly every one walk away ok, but the motor was in the cubby behind the seats. sorry to hijack, I also sail with a new main and wore out jib(no ida rudder) and have to backwind the jib to tack.  Happy Sailing    BILL

[deisher6]

There is a really good thread on windward performance in the C23 section with some current posts.  I was just out for our 3d and best sail so far in cour '89 C16 with original rudder and sails.  10-20 kts of wind.  I tacked downwind for 8-10 miles then tacked back.  Up until I thought about the outing, I was fairly happy with my baggy sails.  However, when beating close to the shore the amount of leeway made was very (very) apparent.  Everything else mentioned in this forum was also there; weather helm, rudder stalling, heeling rather than accelerating, belly of the sail to far aft, unable to tighten the jib enough to get the scallops out of the luff of the jib

It is new sails and Ida Sailor rudder for me next season.

What an enjoyable sail though, first time with a crew.  Our daughter was home on leave. (+;

Soon may be the boss will come out with me.

regards charlie

[skip1930]

As Rich Hutchins always said, " People tend to crab into the wind too much."

It is what it is. skip.

[Bob23]

Salty:
   A brief note on foiled rudders: I recently retrofit a Hobie 16 blade to my Force 5. What a difference. Faster, comes about quicker although she will round up faster in a gust...not a bad thing.
   Another note: Anyone out there notice that our keels are foiled shaped? Duh....there is a reason why. Buy the foiled blade, make one, steal one but dang it_ get it!
   I may make my next blade to NACA 0012. I made my wood blade to 0014 shape. I don't think Koinonia will know the difference.
bob23

[JBC]

A brief and useful discussion on tacking/sailing to wind in light air appears on The Sailboat Company Q&A website, the 9/20/11 post:  http://www.ipass.net/sailboat/

[Salty19]

B.hart---very cool...I had the '91 model as well. I drooled over them for years until I bought one in 2005.   I was running it around 12psi of boost--crank it up to 16 and there wasn't much out there that could keep up with it! It did well in the curves but you do have know how to drive it..as your son found out!  Easy to crash them if you're not familar with oversteer.

Bob..your idea is EXACTLY my thoughts as well.  What you need to find out is the maximum width of the foil on a CP23 (1 1/4" for a CP19, but yours is probably fatter) to get the right width for the application.  From there, I can probably help you with a template as I have a NACA0012 cross section. I could trace it, then blow up the trace to proportion on a copier.

Also pay extra special attention to the angle of the blade and the distance from the rudder pivot to the tip of the the blade.  I suspect even a fraction of an inch difference in these dimensions makes the difference between a light helm and a moderate one.

The NACA0012 should make your boat a tad faster, the careful placement of the foil should help with decreasing weather helm.

Kick is right abuot weight distribution.  Makes a big difference overall to how she sails.