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Jon - CLou
Joined: 02 Nov 2003 Posts: 316 City/Region: Port Angeles
State or Province: WA
C-Dory Year: 1986
C-Dory Model: 22 Angler
Vessel Name: C-Lou
Photos: C-Lou and Pee Wee
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Posted: Sat Jan 22, 2005 7:56 pm Post subject: |
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Quote...Did you notice any straight line steering differences?
The boat pulled to the right only when I backed off the throttle quickly. I did leave my two portside weights at home (Cynthia and the 90lb kicker), so, leaning to the starboard side could of caused that. |
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katkt
Joined: 27 May 2004 Posts: 243 City/Region: Pensacola
State or Province: FL
C-Dory Year: 2003
C-Dory Model: 24 Tomcat
Vessel Name: Katie Kat
Photos: Katie Kat
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Posted: Sat Jan 22, 2005 7:59 pm Post subject: |
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Mike,
Yes, I went with the factory recommendation and installed
the twin 90 Hondas. I don't know why there would be a
problem with them on twins as per Charlie above. The forum
I was following before I bought mine, had alot of guys with
twins, and alot of them gage a boat by how long it takes to
break it, and if it will run 50.
One of the interesting side lines I was following had to do
with raising the motors a hole or two, to reduce drag. This is
apparently made possible because, the foil holds the water
over the prop better. Just throwing that out for thought.
Its my opinion but I would think that if the foil flexes you
probably aren't getting its real worth. They have been selling
them for awhile, if motors are being torn up I can't think of
anyone who would be bashful about getting the news out.
Gordon |
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C-WEED
Joined: 14 Mar 2004 Posts: 338 City/Region: New Brockton
State or Province: AL
C-Dory Year: 2000
C-Dory Model: 22 Cruiser
Vessel Name: C-Weed
Photos: C-WEED
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Posted: Sun Jan 23, 2005 12:29 am Post subject: |
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How about one tested on a dingy? _________________ Chris |
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Mighty Bite
Joined: 02 Nov 2003 Posts: 456 City/Region: Fairbanks, Alaska
State or Province: AK
C-Dory Year: 2004
C-Dory Model: 16 Angler
Vessel Name: Mighty Bite
Photos: Mighty Bite
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Posted: Sun Jan 23, 2005 3:41 am Post subject: |
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Already tested it on me. _________________ Mark on Mighty Bite |
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katkt
Joined: 27 May 2004 Posts: 243 City/Region: Pensacola
State or Province: FL
C-Dory Year: 2003
C-Dory Model: 24 Tomcat
Vessel Name: Katie Kat
Photos: Katie Kat
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Posted: Sun Jan 23, 2005 11:48 am Post subject: |
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I hope I'm not violating a rule here, but if you do a search for
The Hull Truth, scroll down to the vendors forums you'll
find a QandA with feed back under Permatrims, I had already
ordered some of the plastic whale tail thingies when I found
these.
This is as close to an endorsement as you'll get out of
me until I have a chance to install them and try them out.
Gordon
3rd Byte, I had to read that 3 times before it clicked,
I'm slow  |
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SeaSpray
Joined: 12 Mar 2004 Posts: 1009 City/Region: Brentwood, CA
State or Province: CA
C-Dory Year: 2004
C-Dory Model: 22 Cruiser
Vessel Name: SeaSpray
Photos: SeaSpray
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Posted: Sun Aug 07, 2005 10:38 pm Post subject: |
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After installing my Permatrim a few weeks ago I finally got to give it a real try. (Last time out the water intake got clogged with sea grass and I lost one of the plastic intake screens - but that's another story.)
Although conditions were not the best for assessing any changes I could not tell that much difference. I did notice that at higher speeds if I trimmed up the boat would start to porpoise. I don;t think it did that with the smaller foil. Hs anyone else noticed this?
I did do some hard turns and it does seem that the stern will not slide or wash out with the permatrim.
Steve |
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Sea Wolf
Joined: 01 Nov 2003 Posts: 8650 City/Region: Redding
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Cruiser
Vessel Name: Sea Wolf
Photos: Sea Wolf
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Posted: Sun Aug 07, 2005 11:58 pm Post subject: |
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Steve- I think the increased tendency to porpoise comes from the greater EFFECTIVE range of trim available with the hydrofoil. Although the angular range is the same, the foil increases the effect of the trim angle through the action of the foil plate. Thus you can trim the bow up enough to make it so light as to be unstable. (The plate gives you more at the other end of the trim range, too, to force down the bow.)
The lesser ability to slide or wash out the prop and lower end comes from the insulating effect of the plate above the prop and, in the case of the Permatrim, the turned down edges of the sides of the plate.
JMHO and not at all costing you $0.02 even!!! Joe. _________________ Sea Wolf, C-Brat #31
Lake Shasta, California
 
"Most of my money I spent on boats and women. The rest I squandered'. " -Annonymous |
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Da Nag
Joined: 24 Oct 2003 Posts: 2832 City/Region: Port Angeles
State or Province: WA
C-Dory Year: 1995
C-Dory Model: 25 Cruise Ship
Vessel Name: Wilbur
Photos: Da Boats
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Posted: Mon Aug 08, 2005 10:50 am Post subject: |
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seabran wrote: | I did notice that at higher speeds if I trimmed up the boat would start to porpoise. |
Can't remember, Steve - do you have trim tabs?
If so, make sure at higher speeds your engine is trimmed so the thrust line is parallel with the hull bottom - I've got a mental note on my engine trim guage where that is. Then use the tabs to adjust the bow height. I've never had a porpoising problem with my Permatrim/tab setup doing this.
If you don't have tabs, well...the TrimMasters are on sale.  _________________
Will, C-Brat Nerd  |
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SeaSpray
Joined: 12 Mar 2004 Posts: 1009 City/Region: Brentwood, CA
State or Province: CA
C-Dory Year: 2004
C-Dory Model: 22 Cruiser
Vessel Name: SeaSpray
Photos: SeaSpray
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Posted: Tue Aug 09, 2005 12:15 am Post subject: |
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Bill - I do have the trim tabs. I have not really looked at the motor angle while on the trailer. I am wondering if you can tell when the thrust is parallel to the bottom when on the trailer? I don't think I could tell while motoring - by feel.
It seemed that my trim gage was just above the midpoint when it started the porpoising. I also wonder if the range of trim has been off set so that I will now need to run with trim set below gage midpoint for normal conditions.
Steve |
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TyBoo
Joined: 23 Oct 2003 Posts: 5328 City/Region: Warrenton
State or Province: OR
C-Dory Year: 1996
C-Dory Model: 25 Cruise Ship
Vessel Name: TyBoo
Photos: TyBoo
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Posted: Tue Aug 09, 2005 12:34 am Post subject: |
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Da Nag wrote: | If so, make sure at higher speeds your engine is trimmed so the thrust line is parallel with the hull bottom |
Is that how you meant to say that? I have found it to be the most efficient to keep the "thrust line" parallel with the water surface or slightly trimmed under. The hull line is usually up a bit in the front when on step.
Seabran wrote: | I don't think I could tell while motoring - by feel. |
On my CD22, the motor trim gage was pretty close to common sense acurate (~level at half scale). On the CD25, the transom angle is not as great, so the motor trim gage is essentially worthless, because the motor is always trimmed nearly full down. It doesn't tuck under much at all. The easiest way for me to tell if it is trimmed square to the water is to glance out the door at it. The top of the cowling is eyeball parallel to the prop shaft, and when at cruise I trim the motor so the line of sight over the cowl is parallel to the water. I like to use the tabs to set the hull attitude, and then trim the motor square to the water. Doing so gives me optimum economy.
I am going to try one of those PermaTrim jobs, I think. I need a little more lift aft without shoving the bow down more. I wonder if Jon still has the PermaDork? _________________ TyBoo Mike
Sold: 1996 25' Cruise Ship
Sold: 1987 22' Cruiser |
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SeaSpray
Joined: 12 Mar 2004 Posts: 1009 City/Region: Brentwood, CA
State or Province: CA
C-Dory Year: 2004
C-Dory Model: 22 Cruiser
Vessel Name: SeaSpray
Photos: SeaSpray
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Posted: Tue Aug 09, 2005 12:40 am Post subject: |
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Thanks Mike,
I will try that method next time I am out. It does make sense for the motor to be parallel with the water surface.
Steve |
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Big Mac
Joined: 02 Nov 2003 Posts: 189 City/Region: Chehalis
State or Province: WA
C-Dory Year: 2001
C-Dory Model: 22 Cruiser
Vessel Name: Mary Ellen
Photos: Mary Ellen
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Posted: Tue Aug 09, 2005 1:24 am Post subject: |
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Might as well throw in my two cents worth. The Mary Ellen has twin 40 HP Hondas. The only complaint I had was the ability to get lateral trim without going to trim tabs. I ordered a set of Honda SST hydrofoils and did not like the way they mounted(didn't even drill any holes, just held them up and did not like the looks). I had just about given up when I stumbled on to the Permatrims. I have now had them going on the second season and really like the way the boat handles. Just a touch on the trim button and the side to side trim is corrected. I am concerned with the following sea potencial handling problem but have never encountered any problem yet. I wonder if the fact that the Permatrim is deeper in the water would help to minimize the effect? As far as quality and how they look I could not be happier. It also seems to handle better at slow speeds around the dock, it's more responsive. |
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Falco
Joined: 20 Dec 2004 Posts: 164 City/Region: Flagstaff
State or Province: AZ
C-Dory Year: 2004
C-Dory Model: 22 Cruiser
Photos: Bucking Coho
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Posted: Tue Mar 07, 2006 12:09 pm Post subject: |
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The US rep for Permatrims (shipyardisland.com) had no info about Permatrims and broaching in following seas, but here's what the manufacturer of Permatrims (in NZ) says about broaching in following seas:
Permatrims work differently to trim tabs and should not make a boat more susceptible to broaching in a following sea, they will help to stop your boat from broaching by giving your more trim control so you can hold your bow up, this is one area were permatrims differ from trim tabs, trim tabs cannot lift your bow only lower it.
I hope that helps explain the difference. If you need any more info please email me and I will try to help out.
Thanks for your enquiry.
Regards
Colin Chapman
I did some research on the Net, but couldn't find anything directly linking trim tabs (or accoutrements like Permatrims) to broaching in following seas, but numerous references (Bennett and Lenco owner's manuals) state that trim tabs should be kept up (retracted) in following seas "to improve handling" and/or to prevent the bow from "digging in" (to the next wave). My personal experience is that extended trim tabs in large following seas (6-10 feet) WILL cause a boat to broach -- and it happens very violently and rapidly, without warning and is uncontrollable. Colin's point above makes sense. If kept trimmed down in a following sea, a Permatrim equipped outboard should function to really keep the bow up - important to prevent digging in to the next wave... |
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