Trim Tabs or Permatrim

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DutchCs

New member
Were running twin 40 Mercury Big Foot engines on our Cruiser 22. Top end is about 22mph with two adults, full fuel, and rigged for trolling on Lake Superior. This is slower that we expected although not a big concern. When on plane at full thottle the bow seems high and falls off to either side quickly with slight wheel input. (no trim tabs installed) Tach is in the 5500-6000 range.
Will trim tabs or permatrim help lower the bow, track better, and increase speed? Or is this more of a prop issue?
 
I have a C-22 with twin 40's (hondas). When I bought the boat it had neither Trim Tabs or Permatrims. The C-dory is a very stern heavy boat, especially if heavily loaded, as I always seem to be. Trimming my bare motors had a barely noticeable effect on the trim of the boat. I initially installed trim tabs and was delighted with the changes. I could get the stern up and I got a marked increase in speed at the same Rpms. After 2 more years I installed permatrims and now I can trim the motors and the boat responds. The result is much improved control, comfort, economy and safety.
Your props may be an issue as well. I am sorting this out on Carpy now.

This subject has been much discussed in these pages and there is a wealth of information and opinion on this site. Check it out .

Bruce Cassal
Carpy
 
Either will help, but both will do it better. I would probably start with Permatrims, and if they do not add enough, then go to the tabs. Usually with single engine boats, the tabs are first, and then the Permatrim. With Twins, you may get away with just the Permatrims. Easier to install than the tabs.

You certainly should be getting higher speeds, and I suspect that you may be hitting the rev limiter of the engine if you regularly hit 6,000 RPM.
 
When I first bought my 22, I got it directly from the factory and the sales guy there at the time recommended against trim tabs or permatrims. I later came to understand that he was an idiot. After several years of operating with twin Honda 40's and no trim tabs or permatrims, I added permatrims. It made a huge difference. Without, when I pushed the throttle up, the bow would rise so high I could barely see over it for a few seconds. With, I popped up to on plane with minimal bow rise. I don't think I gained anything in speed but the transition to plane was much better as was the ability to push the bow down when going into chop.

As others have mentioned, you may be a tad under propped. With twin 40's you should be able to hit 25-27 with the boat loaded and close to 30 if the boat is light.
 
Engine mount height, which you can research on this site, is also in the equation. If too low, the engines can be brought up a hole or two and improve performance.

Check the height after mounting the permatrims: With the boat on plane and the engines trimmed parallel to the hull, the permatrims should ride at the water surface. I installed a permatrim on my Honda 90 this winter, and will soon be checking the engine height.
 
My experience is similar to what Bruce and Dr. Bob relate, but with a single Honda 90 on a CD22.

When I bought the new boat in 2003 it had trim tabs. They worked ok, and definitely provided the ability to control lateral trim and so-so pitch trim.

I wanted more ability to control the pitch trim (bow up/down) so I installed a PermaTrim. Wow, did it ever add to the pitch control! You add that 'big mother of a plate down on the cavitation plate and you'll Definitely get pitch control.

As I reflect back on it, since you (presently) have neither tabs or PermaTrim, I think I'd add the PermaTrim first (it's certainly cheaper...) and if you eventually want more lateral trim control possibly add 'tab's later. My guess is that with twin engines and PermaTrims you'll get a bonus of lateral trim control as well.

Best,
Casey&Mary
 
Thanks for the responses all! We hadnt though about engine mounting height which is another item to check out. We're probably going with permatrims and also evaluating mounting height. Hopefully ice-out is early, cant wait to get Aeolus on the water

Randy
 
We have both - but rarely use the trim tabs. With twins and permatrims - you have great control as you can move each engine separately. Plus my hand doesn't need to leave the throttle to adjust the bow (or side to side). The trim tabs are much harder to adjust as you are cruising.

I'd go with the Permatrims first - may be all you need.


Rogerbum

"recommended against trim tabs or permatrims. I later came to understand that he was an idiot. "
Click to expand...

Very funny...

I don't see how you could have a CD22 without one or the other.
 
I had the exact same experience as Casey except with twin 40Hp Hondas. I definitely want both. If starting with one, go with permatrim first. I started with trim tabs, enlarged them, and them made my own permatrim since the ready made ones would have interfered with my trim tab extensions. Your props appear to be correct if 6000 rpm is redline; getting better boat trim with permatrims may change WOT; if it goes higher, get props with an inch or two more pitch and you'll probably get between 25 and 30 mph (when light) which I consider the expected top speed. I normally run 12-18 mph but check WOT at the beginning of each season. Sorry, ice out is ages away, so be happy skiing for now.

Jay
 
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