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View Full Version : 22 Classic w/o trim tabs?



Ghost
01-24-2010, 01:51 PM
Is there any such animal? I'm curious if anyone has or knows of a 22 Classic that he believes is perfectly fine without tabs of any sort.

And if so, is this predicated on max top end speed being under a certain threshold, counter-rotating drive of some sort, or whatever?

Interested in any and all opinions on this, pro or con.

Thanks,

Mike

Carl C
01-24-2010, 02:51 PM
You need them to control listing when the drive is not trimmed up.

RedDog
01-24-2010, 03:39 PM
... is this predicated on max top end speed being under a certain threshold...

When I run faster, I need no tab. I only use tab at more moderate cruise speeds to stop the porpoising

CHACHI
01-24-2010, 04:40 PM
When I run faster, I need no tab. I only use tab at more moderate cruise speeds to stop the porpoising
X2

Ken

MOP
01-24-2010, 05:07 PM
My 22 did not have them when I got it, I ran the tail end of one season without. I put set on that winter and would not be without to adjust for sea conditions and weight. Mine does not porpois at all since I moved the tank and a few other thing aft!

zelatore
01-24-2010, 05:13 PM
x2
ken
..x3

Planetwarmer
01-24-2010, 09:10 PM
They sure nice to have when the water gets rough, you can add some tabs and the boat will settle right down.

zelatore
01-24-2010, 11:26 PM
The thing that comes to my mind -

You don't have a 22, so why are you asking?

Are you up to something?

Ghost
01-25-2010, 12:06 AM
The thing that comes to my mind -

You don't have a 22, so why are you asking?

Are you up to something?

Congratulations! Good thinking.

But no, I am only doing some pondering, so far. Having driven some boats (with admittedly less deadrise) that show no signs of wanting tabs, I am left wondering if tabs are a necessary crutch for design problems.

At the same time, I wonder if my own boat, repowered with outdrives (twins, or a big single) instead of inboards, would still have any need for tabs. I see a slight tendency toward porpoising at certain speeds. Tabs can cure it, but so can throttle mgmt, done right.

A lot of 22 Classic issues that require tabs would seem to be mitigated by a duoprop. But some VERY high speed quirks, as well as some just-above-planing-speed quirks, would seem to cry out for them as well also.

Anyhow, I am interested in what people think. Having driven boats that do not need tabs, I am curious if there is a recipe for those of us with deepeer Vs that would eliminate the need. Well, at least, perhaps do so. Each hull is different.

Mikeh

Planetwarmer
01-25-2010, 12:28 AM
It seems to me that a majority of the fast boats that I have seen have tabs. I think it allows a pilot to customize the shape of the hull for varying conditions. I bet those boats that you rode in/drove with a less steep dead rise did not handle rough water as well. It would be difficult to design a hull that would be ideal in fast and slow, rough and smooth conditions. Tabs are used like ailerons on an airplane, not just porpoising preventatives. I would bet the porpoising issues could also be addressed by proper balancing of the weight distribution.

There are better designs out there now for sure, our hulls are from roughly circa 1960s. I'm a gadget guy. I dont mind using tabs, even if they are a crutch. It gives me something (else) to play with while on those long rough water rides.

VetteLT193
01-25-2010, 07:01 AM
Eddie's 22 requires no tabs at all. I find it easier to balance the load (i.e. move a person around) than it is to use the tabs. There is no porpoise at any speed.

They do help maintain a slow plane. They are excellent when it is rough and you need to get home. tab down the bow into the water and let the bow do the pounding.

So, with that said, I wouldn't have a 22 without them for the few times you want to use them. But... running a 22 without them is certainly very very doable.

On another note, Cuda's old 22 did not have them. I think Howard O has it now.

gcarter
01-25-2010, 07:24 AM
The Minx obviously wasn't a 22, but it was close in size and shape.
It did not need tabs except for cruising at 20 MPH (Elaine's favorite speed).
Everything was taken care of by drive trim. The handling was completely benign and in calm water at full speed (65 on a cool day) you could take your hands off the wheel (only to see if I could...not normal practice).
Like Bob said, it's easier to move passangers around.

MOP
01-25-2010, 07:58 AM
Ah we have not brought to light the absolute best feature of having tabs on our boats! Hands off at idle speeds when you put the tabs full down, they eliminate the side to side wondering all single engine deep V's have. There is nothing else that eliminates the WAG not even hydraulic steering!

Carl C
01-25-2010, 08:12 AM
Congratulations! Good thinking.

But no, I am only doing some pondering, so far. Having driven some boats (with admittedly less deadrise) that show no signs of wanting tabs, I am left wondering if tabs are a necessary crutch for design problems.


They are needed due to the design of the hull but not because of a design "problem". These hulls have no pad and roll around on a rounded keel. This produces a list due to prop torque when the drive is tucked in such as when planing or running slowly. You will need to run some port tab to compensate. As you increase speed and raise the drive the prop torque goes away and you can lift the tab. The tabs are up for high speed running. Running at speed in rough water will require you to drop the drive a bit and the list will return so you need to drop the port tab a bit. You can lower both tabs to keep the boat running level in the rough also. Except for all out top end running I am constantly tweaking tab and drive positions for the conditions. The 22C is a driver's boat and to me the driver input and skill contibute to making it such a fun boat to drive. I can not imagine one without tabs. Mine would be dangerous without them as it would plane out with a severe list. Before planing I lower the port tab for 5 seconds (dual rams, no indicator). As the drive comes up so does the tab. They can also control porpoising but my boat does not have that problem. Some people claim to drive the 22C with no tabs but they are few and far between.

oledawg
01-25-2010, 08:19 AM
Carl C is right on the money!

CHACHI
01-25-2010, 08:52 AM
Ah we have not brought to light the absolute best feature of having tabs on our boats! Hands off at idle speeds when you put the tabs full down, they eliminate the side to side wondering all single engine deep V's have. There is nothing else that eliminates the WAG not even hydraulic steering!

This is the only way I get from "off plane" to my boat house with out wearing out my arms.

Ken

CHACHI
01-25-2010, 08:56 AM
Carl C is right on the money!

I will buy that explaination too.

Ken

Pismo
01-25-2010, 09:23 AM
They are needed due to the design of the hull but not because of a design "problem". These hulls have no pad and roll around on a rounded keel. This produces a list due to prop torque when the drive is tucked in such as when planing or running slowly. You will need to run some port tab to compensate. As you increase speed and raise the drive the prop torque goes away and you can lift the tab. The tabs are up for high speed running. Running at speed in rough water will require you to drop the drive a bit and the list will return so you need to drop the port tab a bit. You can lower both tabs to keep the boat running level in the rough also. Except for all out top end running I am constantly tweaking tab and drive positions for the conditions. The 22C is a driver's boat and to me the driver input and skill contibute to making it such a fun boat to drive. I can not imagine one without tabs. Mine would be dangerous without them as it would plane out with a severe list. Before planing I lower the port tab for 5 seconds (dual rams, no indicator). As the drive comes up so does the tab. They can also control porpoising but my boat does not have that problem. Some people claim to drive the 22C with no tabs but they are few and far between.


I am surprised by this. I have no list when planing and little use for tabs. I plane at 2000rpm or just above so lightly and slowly. I don't nail it to get on plane. I only use tabs to balance the heavy guy sitting in the passenger seat or to tip the V slightly into the chop on a windy day to improve ride. Above about 35mph I find them un-necessary for the boat levels out nicely and settles in nicely. Even more the faster you go. I can stop my porpoise with trim and throttle. So I never use them above about 35mph, esp at wide open, and below that only to level. I could fairly easily live without them all together by moving people around. I admit I am kind of an anti-tab mentality guy because they cause so much drag and make boats feel so heavy. I am more of a trim and throttle guy. 22s like trim and are very responsive to trim and throttle.

VetteLT193
01-25-2010, 10:12 AM
I am surprised by this. I have no list when planing and little use for tabs. I plane at 2000rpm or just above so lightly and slowly. I don't nail it to get on plane. I only use tabs to balance the heavy guy sitting in the passenger seat or to tip the V slightly into the chop on a windy day to improve ride. Above about 35mph I find them un-necessary for the boat levels out nicely and settles in nicely. Even more the faster you go. I can stop my porpoise with trim and throttle. So I never use them above about 35mph, esp at wide open, and below that only to level. I could fairly easily live without them all together by moving people around. I admit I am kind of an anti-tab mentality guy because they cause so much drag and make boats feel so heavy. I am more of a trim and throttle guy. 22s like trim and are very responsive to trim and throttle.

+1

The 22 shouldn't take but a few seconds to get on plane anyway. I would be on plane before having a chance to lift a tab up.

I have to guess this whole issue comes down to specific boat setup and driver skill for a specific boat.

Dr. David Fleming
01-25-2010, 11:15 AM
If we might take a parallel from aircraft design, the modern wing on a comerical jet has a leading edge that moves forward and an elaborate set of flaps that extend the rear of the wing. This provides great lift and low air speed and allows the wing to lift more than it could in high speed configuration. These wings are sometimes called "magic carpet wings."

Tabs on a high performance hull might be considered in the same light. The tabs help control the plane of the hull rising out of the water and under certain mind range load conditions. General advice is to not use them at extreme speed.

This however brings in another aspect of trim tabs that Chris Cxxxxxx the donzi engineer told me about. The tab makes the boat act as a longer hull. Tabs extending parallel to the hull at high speed add to the water drag but also make the hull act longer, as if a 23 foot hull was planing instead of a 22 foot hull.

In this context they have a dynamic effect. If the hull is a performance problem at high speed lowering lowering the tabs can calm the hull performance and can dramatically effect the performance. Sometimes for the good and sometimes not. It can cause the hull to trip in certain high wave conditions at speed leading to stuffing. Yah!

AR-Cougar
01-25-2010, 03:54 PM
Had the opportunity to test mine with and w/out.
Bought the forum's suggestion to install a pair of Bennett's.

Huge difference when running in rough/choppy waters! I get better speed/smother ride by combining tabs+trim than by just adjusting trim. Even at WOT.

Under certain weather conditions its definitively safer to ride with tabs.

In my case, gas level (bow weight) is also a factor. Probably my humble 260HP is also something to keep in mind.

IMO, even if you don't generally use them, it's worth having the option.

zelatore
01-25-2010, 03:59 PM
.

IMO, even if you don't generally use them, it's worth having the option.

And there you go.

If you are really considering converting your rig from inboard to stern drive, the added cost of tabs is insignificant and it would be very well worth it to add them. You don't need to pop for K-planes, just a set of Bennets will work fine. Unless you've got some crazy plans for power I don't know about, I don't see you pushing that hull much past 65. Aren't you running mid 50's now with the inboard small blocks?

Also, fwiw, I think a single big motor with a duo-prop might be pretty kick-ass on that thing. Maybe 550 or so hp, though you might want to check with some of the experts about how well the duo-prop handles that kind of load.

mc donzi
01-25-2010, 04:13 PM
And there you go.

If you are really considering converting your rig from inboard to stern drive, the added cost of tabs is insignificant and it would be very well worth it to add them. You don't need to pop for K-planes, just a set of Bennets will work fine. Unless you've got some crazy plans for power I don't know about, I don't see you pushing that hull much past 65. Aren't you running mid 50's now with the inboard small blocks?

Also, fwiw, I think a single big motor with a duo-prop might be pretty kick-ass on that thing. Maybe 550 or so hp, though you might want to check with some of the experts about how well the duo-prop handles that kind of load.

Have read either here on the board or in Volvo literature that their DPX drive will handle up to 600 HP without any mods. Love my 454-385 DPX. BTW, mine has short(12") K-planes...hardly ever use 'em.

MOP
01-25-2010, 05:15 PM
Pismo if you are alone you will not have noticeable list, but put a passenger of near equal weight and the boat will lean from prop torque. I need the port tab down 1-1/4" which I measured once just to see where it has to be when Bonnie is with me, unless I run into sea conditions warranting a change I just leave it there as I don't get out much by my self!!!

CHACHI
01-25-2010, 06:19 PM
Unless I am out on the water at 6 in the morning I never run in smooth water. Between the river current, waves, and wind blown chop, I am always using my tabs.

Even when I had my Minx, I used my tabs.

Now that I have installed a tab guage, more often than not, I have one tab a tad lower to maintain additude.

We even installed tabs on my Father in laws Grady.

Bottom line, they work.

Ken

Conquistador_del_mar
01-25-2010, 06:42 PM
I have personally always had or installed trim tabs on every deep V hull I have ever owned. There are too many uses for them to leave them out of the equation in my book. I find them particularly useful when taking waves diagonally. You can lean the boat slightly away from the incoming waves to let the V do the cutting instead of slapping the sides of the bow - makes for a much better ride and lessens the blows. I drove my 1971 18' Donzi for about 4 years in the early 70s without tabs, but after I installed them, I never went without them again. My two cents, Bill

Ghost
01-25-2010, 08:15 PM
And there you go.

If you are really considering converting your rig from inboard to stern drive, the added cost of tabs is insignificant and it would be very well worth it to add them. You don't need to pop for K-planes, just a set of Bennets will work fine. Unless you've got some crazy plans for power I don't know about, I don't see you pushing that hull much past 65. Aren't you running mid 50's now with the inboard small blocks?

Also, fwiw, I think a single big motor with a duo-prop might be pretty kick-ass on that thing. Maybe 550 or so hp, though you might want to check with some of the experts about how well the duo-prop handles that kind of load.

I already have tabs, actually. Was wondering if I could dump them if I went to a drive with trim.

I'm only at mid 40s right now, but think I could get to 47 or 48 with my sick carb rebuilt.

But on to dreams. You have my thoughts pegged. I was thinking 550 and a DPH drive would be pretty awesome. Maybe even 500 or 525 would do, but 550 was what I pictured. Maybe a DPX. Not sure I'd need it. (For those who I have confused with this, my boat is a Nova Marine 24 with twin small blocks and v drives.) I'm guessing the 800lb+ weight savings and efficiency gain with an outdrive would see top end of 60-65. Which would be pretty bada$$ for a Nova.

But that aside, I am interested in the continuing discussion of 22 Classics and the need or lack thereof for tabs. Especially interested in the duoprop owners' views.

Thanks,

Mike

Just Say N20
01-25-2010, 08:58 PM
My first 18 had them, and I used them all the time. Second 18 didn't have them, and after running the boat without them for a short time, I installed a pair. My 16 doesn't have them, and I am going to install them.

Do you NEED them? You could look at it like this. Do you NEED good shocks on your car? I'm sure all of us would say, "yes!" But we have all seen cars bouncing down the road, as if they had no shocks at all.

Just as a car can operate (although it would be questionable how safely) with dead shocks, a boat will operate without trim tabs. However, just as new shocks will improve the performance of a car, trim tabs will improve the performance of the boat in the ways many have illustrated above.

As a group, I would say we tend to want to get the most performance out of our boats, and tabs provide another tool that allows us to fine tune the boat for the water conditions, speed, load, etc.

So, do you NEED them? Not necessarily, but they sure are nice to have. :biggrin:

realbold
01-26-2010, 03:11 PM
Mike, if you go with a single I/O you're ok with tabs. I don't believe theres enough room for tabs on your transom with twin I/O's (without modifying the transom). I know, mine's the same.
Duoprop or B1 your boat would be kick a$$ with a single BB.