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John C in PA
12-07-2010, 02:17 PM
Guys, are the Bennett M80's OK or should I go for the ST9's?

John C

MOP
12-07-2010, 06:51 PM
IMO either will do the job, the M80's are a tad longer that may be a benefit not sure. I had the ST9's on my 16 they did a good job, one thing you will be very pleased with the added control.

Phil

LKSD
12-08-2010, 10:03 AM
Correct, both are good & will work. A twin ram set up tho is a little overkill on the 16.. A single ram for each tab will usually respond a little quicker too, as there is less fluid for the single pump to move.. :) Jamie / Lakeside

John C in PA
12-08-2010, 11:56 AM
John C

LKSD
12-08-2010, 02:53 PM
Sorry, about that.. lol

I forgot they do offer the single ram in that series too. I only took a quick glance in our book earlier at them.

Personally I like Lenco's stuff or going into an all out K plane style tab better. But I opinions are subjective and some of that stuff in all honesty (like the K plane) is Waaayyy overkill for your 16.. :)

IMO.... I like Lenco's set up because they are pretty quick, there is no hydraulic pump or hydraulic lines to worry about and they seem to from our experiences to date hold up just as well. Despite what Bennett claims. Also I like their switches & indicators better. It is a bit more simplistic but effective setup & design.

:) Jamie / Lakeside

bertsboat
12-08-2010, 03:25 PM
There is still a set at The Marine Connection in Stuart ASK FOR THE MODEL 110. They come with pumps attached. Pricey I must admit $1300

Just Say N20
12-08-2010, 03:37 PM
Bennett has about the best customer service you will ever encounter anywhere.

I bought the M80 without any indicators for $428+ shipping for my 16. To try something different, I mounted them horizontally and up a little to make sure there is no dragging.


Can be seen in my signature.

John C in PA
12-08-2010, 06:29 PM
John C

glenncal1
12-09-2010, 08:41 AM
John C-I have a new in box set of Bennets M80EIC (electronic indicator control) for $500 plus shipping if you are interested. Jim


Popular opinion seems to be that Bennett CS is the best. I have to assume that doesn't mean that their parts break a lot :eek:. From surfing this and a few other boating websites I sure don't see too many guys promoting Lenco's (except maybe that boat restorer guy in PA, Jamie sumpthin' or other :wink:). Overall most folks seem to like Bennetts.

The us vs. them comparisons on the supplier webpages bring up interesting points, most of them (to me) favoring Lenco. However, I like the way a good hydraulic system can be manipulated. The ST9's still seem to be the best for my little boat as they are rated to 60 MPH. Bennett's literature doesn't rate the max MPH for M80's.

Bill, do you think your install provides the same handling as tab plates which are parallel to the deadrise? Better? worse?

John C in PA

John C in PA
12-09-2010, 09:51 AM
John C

Just Say N20
12-09-2010, 10:40 AM
Bill, do you think your install provides the same handling as tab plates which are parallel to the deadrise? Better? worse?

John C in PA

I called Bennett and they recommended the ST9 for my application (16' Donzi Ski-Sporter with a projected top speed of mid-60s).

I decided on the M80 because I have had (2) Donzi 18 2+3's that both had single hydraulic ram Bennett trim tabs. One ran 58, and the other ran 64. I never experienced any trouble of any kind with them. I also HYPOTHOSIZED (meaning I don't know, but it seemed logical) that the single ram would react more quickly because the fluid was moving one, not two cylinders. In this case, I preferred faster.

Regarding the way I mounted them, it is somewhat of a test. The boat is not reassembled, so I have not yet run it.

Both my previous boats had the tabs mounted parallel to the bottom of the hull. I never had any problems with their performance. On this hull, because it is a relatively small hull, and after talking to many high performance people, I decided to try a horizontal mounting. I think it should give me more precise control because it would be a gradually increasing amount of tab surface area coming into contact with the water, the further the tab is deployed.

Equally important, there was an obstruction on the inside of the hull that would have created a mess had I installed them parallel to the bottom because of where the top of the cylinder hit the transom, and where the resultant holes would have gone through the transom.

I would have been fine mounting them parallel to the bottom, but decided to try this. Spring 2011, when the boat finally gets run, I will post as to how it works.

Just Say N20
12-09-2010, 10:43 AM
Another thought. If I had been building a boat that I knew was going to run 70+ mph, I would have probably bought the ST9 tabs.

If you aren't planning on going that fast, I would jump on the tabs offered by glenncal1 in a heartbeat. That is a great price for the M80 with the electronic indicator control.

John C in PA
12-09-2010, 12:40 PM
John C

Just Say N20
12-09-2010, 01:23 PM
Come next spring I will know for sure.

As I have thought about the effect of the tabs on chine-walking, I think these might actually be better. And I realize this is pure speculation.

If there is only a mild chine walk oscillation, then only a mild correction should be needed. With the tabs mounted horizontally, initially only the outer most edge of the tab will come into contact with the water, so the amount of force exerted will be small. If the side to side action is more pronounced, then a greater amount of the tab will be forced into the water, providing a greater force to stabilize the boat.

Therefore the greater the force exerted by the chine-walking onto the trim tab, the progressively greater amount of counter force will be applied, as more and more surface area of the tab is forced into contact with the water.

When the tabs are mounted parallel to the bottom, the entire tab hits the water, regardless of the severity of the chine-walk oscillation. It would seem to me that in this situation, you would have to change the amount of force by extending/retracting the tab, until the correct balance is obtained. From first hand experience, fine tuning a trim tab setting while trying to drive a boat that is chine-walking, is difficult at best.

Or, I could be full of órap.

yeller
12-09-2010, 02:02 PM
Thx Glenn, but the ST9's are still on top of the list. I don't expect to be buying any tabs for a coupla months so you never know.

John CIf your planning on waiting, contact me when you want to buy. I will probably have my set off by then and willing to sell. They will come complete with pump as well as the Bennet indicators.

I don't have a great picture of them, but you can see the one in the attached pic.

Work great, I'm just going bigger.