Doel Fins VS. Trim Tabs--Which are better?

Doel Fins VS. Trim Tabs--Which are better?

Post by Duncan D. Sterli » Sat, 13 Jul 1996 04:00:00


I'm considering installing either doel fins or trim tabs on my 17 foot
runabout with a 100 hp outboard.

I've heard conficting reports as to which option is better for helping
a boat to plane sooner.  Which works better, and why?

Thanks in advance...

 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by Ted Park » Sat, 13 Jul 1996 04:00:00

I have a 17.6' modified deep vee hull with a 90 hp and a  9.9 kicker
and 4 gas cans stored under the rear well of the boat. Probably not the
greatest weight distribution. I installed a Doelfin last year to help get on
plane faster. It seems to have helped a little, but it certainly wasn't a
"wow" type of improvement.

However, the Doelfin was cheap, and it hasn't hurt the performance in anyway,
so what the heck.  There are so many variables, you won't really know
how a fin works until you try it.

I think trim tabs will outperform fins every time. I have heard that
the larger fins (stingray, etc.) put more stress on the leg than does the
doelfin.

Hope this helps,
Ted



Quote:
>Subject: Doel Fins VS. Trim Tabs--Which are better?
>Date: 12 Jul 1996 15:41:08 GMT
>I'm considering installing either doel fins or trim tabs on my 17 foot
>runabout with a 100 hp outboard.
>I've heard conficting reports as to which option is better for helping
>a boat to plane sooner.  Which works better, and why?
>Thanks in advance...


 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by Eddie Moo » Mon, 15 Jul 1996 04:00:00



Quote:
>I'm considering installing either doel fins or trim tabs on my 17 foot
>runabout with a 100 hp outboard.

>I've heard conficting reports as to which option is better for helping
>a boat to plane sooner.  Which works better, and why?

>Thanks in advance...

Bob's Machine Shop in Ruston Fl. makes a trim plate that bolts to the
cavitation plate . It doesn't stick out to the side like Doel fins and
is a lot better looking product. I have had one on my boar for the
last five years with no problems in the stress area. It gets out of
the hole a lot faster and makes the boat handle like a larger boat.
Trim tabs will knock a little off your top speed (unless you spring
for the adjustable ones) and in my experiance didn't help get out of
the hole . A friend who has a drag boat recommended the plates to me
and I have been well satisfied.. If you are interested e-mail me and I
can find the phone number, if I remember correctly it was about $30.


 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by G Gotlie » Mon, 15 Jul 1996 04:00:00

Quote:

> I have a 17.6' modified deep vee hull with a 90 hp and a  9.9 kicker
> and 4 gas cans stored under the rear well of the boat. Probably not the
> greatest weight distribution. I installed a Doelfin last year to help get on
> plane faster. It seems to have helped a little, but it certainly wasn't a
> "wow" type of improvement.

> However, the Doelfin was cheap, and it hasn't hurt the performance in anyway,
> so what the heck.  There are so many variables, you won't really know
> how a fin works until you try it.

> I think trim tabs will outperform fins every time. I have heard that
> the larger fins (stingray, etc.) put more stress on the leg than does the
> doelfin.

> Hope this helps,
> Ted



> >Subject: Doel Fins VS. Trim Tabs--Which are better?
> >Date: 12 Jul 1996 15:41:08 GMT

> >I'm considering installing either doel fins or trim tabs on my 17 foot
> >runabout with a 100 hp outboard.

> >I've heard conficting reports as to which option is better for helping
> >a boat to plane sooner.  Which works better, and why?

> >Thanks in advance...

The Doel-Fins work a little bit. There was a slight improvement
getting on a plane at less RPM. The trim tabs are very expensive.
$300-$500. They bring the bow down fast. It just depends on what
you want to spend.
     Gregg        http://web.wt.net/~upsmn
 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by Larry A. Fishe » Tue, 16 Jul 1996 04:00:00

The trim tabs may be expensive, but they are well worth it if you want
your boat to trim out quickly and properly. This is one of those "you get
what you pay for" deals that is even more obvious as far as what works
best. I've tried both, and trim tabs are the hands down winners. I have a
used set of Doel Fins anyone can have for the shipping.

Larry Fisher

 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by marke.. » Fri, 19 Jul 1996 04:00:00

Quote:

> I'm considering installing either doel fins or trim tabs on my 17 foot
> runabout with a 100 hp outboard.

> I've heard conficting reports as to which option is better for helping
> a boat to plane sooner.  Which works better, and why?

> Thanks in advance...These are two different animals.  I have both on my 23 footer.  Trim

tabs are great for leveling the nose in a low speed plane as when making
a long passage into a head sea.  Drive trim won't do this as well.  Trim
tabs also level the boat in side winds, quartering seas and in uneven
load situations.  They do this well and Doel fins don't do it at all.  
The trim tabs provide almost no lift at low speeds but simply add drag
so are very little help in getting on plane.  The Doel fin and it s
imitators are airfoil shped and provide lift at low speeds.  Again,
these are two completely different products for two different purposes.
 A well found craft I/O or outboard, will have tabs, fin and drive trim,
as only drive trim raises the nose on plane and is a must to plane down
large breaking seas without bow steer or burying in the trough.  If you
don't take your small boat onto big water, it probably doesn't matter,
but if you go out with the big boys, you will need tabs and drive trim,
but not hte Doel fin.
Russell Schneider
 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by Larry A. Fishe » Sat, 20 Jul 1996 04:00:00

Part of this dissertation is just not true. Trim tabs certainly do
provide lift at slow speeds. What you describe as drag is the lifting
force of the trim tabs. It is simple physics and force vectors. As soon
as forward progress starts there is an upward force on the tabs. The
force is enough to prevent the rear from "digging in" when full throttle
is applied when taking off. And while a Doel Fin did indeed have a
dramatic effect on my last boat with a 50 hp motor, it provided nothing
noticeable on my latest boat with a 112 hp motor. I'm sure this is up for
debate, but I've been there and done that and spent a fair amount of time
and money to find out how to make my tunnel drive perform right and run
and take off in very skinny water. Doel Fins, or any of their
counterparts simply do not have an effect on any of the large bay boats
running the coast of Texas.

Larry Fisher

 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by Mark Craf » Sat, 20 Jul 1996 04:00:00

Don't forget that a Doel Fin will improve the ride in rough water
considerably...

        Mark

--
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
Mark Crafts                                                   Melbourne FL

 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by John A. Rafe » Sat, 20 Jul 1996 04:00:00

A recent article in Powerboat reports said that Doel Fins ( and all the
other brands) had absolutley no effect on boat performance , unless the
boat was grossley underpowered

 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by marke.. » Sat, 20 Jul 1996 04:00:00

Quote:


> > I'm considering installing either doel fins or trim tabs on my 17 foot
> > runabout with a 100 hp outboard.

> > I've heard conficting reports as to which option is better for helping
> > a boat to plane sooner.  Which works better, and why?

> > Thanks in advance...These are two different animals.  I have both on my 23 footer.  Trim
> tabs are great for leveling the nose in a low speed plane as when making
> a long passage into a head sea.  Drive trim won't do this as well.  Trim
> tabs also level the boat in side winds, quartering seas and in uneven
> load situations.  They do this well and Doel fins don't do it at all.
> The trim tabs provide almost no lift at low speeds but simply add drag
> so are very little help in getting on plane.  The Doel fin and it s
> imitators are airfoil shped and provide lift at low speeds.  Again,
> these are two completely different products for two different purposes.
>  A well found craft I/O or outboard, will have tabs, fin and drive trim,
> as only drive trim raises the nose on plane and is a must to plane down
> large breaking seas without bow steer or burying in the trough.  If you
> don't take your small boat onto big water, it probably doesn't matter,
> but if you go out with the big boys, you will need tabs and drive trim,
> but not hte Doel fin.
> Russell SchneiderI agree with all the responses to this post and it really depends on the

boat, power, use, and sea condition.
 
 
 

Doel Fins VS. Trim Tabs--Which are better?

Post by 1329C1000-Garry Heon(MT40 » Sat, 20 Jul 1996 04:00:00

Quote:


>> I'm considering installing either doel fins or trim tabs on my 17 foot
>> runabout with a 100 hp outboard.

>> I've heard conficting reports as to which option is better for helping
>> a boat to plane sooner.  Which works better, and why?

>> Thanks in advance...These are two different animals.  I have both on my 23 footer.  Trim
>tabs are great for leveling the nose in a low speed plane as when making
>a long passage into a head sea.  Drive trim won't do this as well.  Trim
>tabs also level the boat in side winds, quartering seas and in uneven
>load situations.  They do this well and Doel fins don't do it at all.  
>The trim tabs provide almost no lift at low speeds but simply add drag
>so are very little help in getting on plane.  The Doel fin and it s

Oh really.  My boat planes alot faster with the K-planes dropped half
way.  They also provide enough lift to the boat up on plane at slow
speeds.  For the boat in questions a set of Bennets would be prefect.

Quote:
>imitators are airfoil shped and provide lift at low speeds.  Again,
>these are two completely different products for two different purposes.
> A well found craft I/O or outboard, will have tabs, fin and drive trim,
>as only drive trim raises the nose on plane and is a must to plane down
>large breaking seas without bow steer or burying in the trough.  If you
>don't take your small boat onto big water, it probably doesn't matter,
>but if you go out with the big boys, you will need tabs and drive trim,
>but not hte Doel fin.

That's right, you'll never see a Doel Fin on any of the "big boys".  You'll
probably not see Bennets either.  You will see K-planes though.

Quote:
>Russell Schneider

Garry Heon
First Stepp

My Opinions....Lucent's Network.