Drop Fins On A Ranger 27

[j&lgray]

I have read the posts that sing the praises of Bennett Drop Fins that are added to the existing trim tabs. Brian and others have Cutwaters that are going 20 MPH and the drop fins make for a flatter ride.

I am wondering if an owner of a Ranger 27 with the inboard diesel had used drop fins to improve the boat's performance. If so, what were the results and would you do it again.

 

[rpmerrill]

I'm replying just to see the answers and get included in this thread.

 

[Rocky]

I did it in on a Ranger 29S. Inboard Diesel 13-15 knot cruise. I didn't get huge improvements in speed or fuel burn...maybe a little. I did get a lot more stable ride at cruise. I did get trim tabs that felt like they had a lot more authority. I am happy with the addition and would do it again.

Buying the kit and the bolts is about $50. It was a very nice mod for $50.

Maybe that helps.

Rocky

 

[tlkenyon]

I did the drop fins on a 25sc, which is very similar to a diesel 27. I can run at the same bow angle with less "tab angle" because of the effectiveness of the drop fins...and with less attendant drag. I did not pick up any speed on the top end, but did gain a few tenths of a GPH in economy...again, because of less drag. It is a success in my book. Go for it. Installation with the boat on a trailer was pretty painless...couple of hours.

 

[BB marine]

I have read the posts that sing the praises of Bennett Drop Fins that are added to the existing trim tabs. Brian and others have Cutwaters that are going 20 MPH and the drop fins make for a flatter ride.

Just a clarification. My WOT is 20 to 21 mph. The Ranger 27 is as fast if not faster than the C26. The performance at WOT really didn't change except when the boat was stern heavy ( dingy and motor) (Extra passengers) (Auxiliary fuel tank full) The R27 probably will not change WOT either.The Drop fins did help the C26 and I have heard from several R27 owners a 10 Kts to 15kt cruise range performance and handling improved. The drop fins trap water under the plane which adds to stern lift. A typical semi displacement hull design doesn't plane just digs a hole at the stern. The drop fins helps reduce the hole increasing the visibility forward. In my opinion drop fins will enhance the handling of theses narrow beam boats in all sea's except following.

John I know you are asking for R27 input which is a completely different hull design. The misconception that the C26, C28 or C30 have a performance hull design is not correct (my opinion ). I actually feel the Ranger's bottom design is faster. Horse power is the only component that could make a Cutwater faster. No matter what Ranger Tug or Cutwater model you own. Inboard or outboard the drop fins will help lift the stern. They all need that because of design.

I'm not a Naval architect or Marine engineer just a boater so critiquing a designers hull is just opinion. The Livingston hull designs have been around for a long time. Many of the 80's early 90's Bayliner's were designed under Dave Livingston's watch. These designs have proven themselves over time but all had one fault ( my opinion). Stern heavy !!! Bennett Trim tab designed and made what is now known as Bayliner drop fin trim tab planes. If you look at any older Bayliner you will find hanging on the back of them, Drop fin planes. All the Bayliner motor yacht line hulls ( great looking hulls) have drop fins installed because they were stern heavy. Some of them have three trim tabs installed port/starboard and a third in between the screws all drop fins. Maybe a few years from now the drop fins will be called Ranger/Cutwater drop fins 😀 .

I will be interested in the responses too. Of course I'm voting for positive reviews :shock:

 

[rpmerrill]

If I remember correctly, just from casual observation at the time, the trim tab "hinge" is simply an interlock bend built into the two pieces. I'm also guessing that, once the actuator is disconnected, the tab can simply be slid to the side to remove and replace it?

I've gotta go visit the boat and measure the existing tabs.

 

[Red Raven]

We have a R27 with a Volvo D3-200 without drop fins. While I don’t have much extra trim I do get to a point where dropping the bow further starts to feel a little over trimmed. At max trim the bow starts to hit the water a little further forward and I can feel the start of increasing drag. I usually back off just a hair from max trim. I don’t think the hull is designed to run any flatter.

Curt

 

[Pddayo]

We have a R27 with a Volvo D3-200 without drop fins. I don’t think the hull is designed to run any flatter.

Curt

Was getting ready to order drop fin tabs and then saw Red Raven’s post. Having a similar boat and experiencing the same issue of the bow plowing when trimming too far forward, decided to hold off. Thanks Curt!

 

[pleeson]

There is no doubt that any of these stern heavy semi displacement hulls benefit from these drop fins. I have a C28 and a friend has the R27. We both added them with noticeably less trim angle required which equals less drag, more speed for the same RPM, and more MPG. The best value for money out there but add a nylon block between the hydraulic ram and the tab to ensure at zero trim the tab is parrallel with the hull rather than angled up so that you are starting the trim action from zero degrees instead of minus 10 degrees. Yes, disconnect the Rams, use a chisel or screwdriver to open up the "pinch" on the hull mounted side of the "hinge" and the tabs knock right out to facilitate drilling and mounting the fins. Sliding them back in is helped by a little grease, silicon, dish soap or what have you. Too bad the Fluid Motion Engineers haven't increased the standard tab square footage, ensured they are flush and parallel with the bottom, and added fins as standard equipment. Without IPS drive we are all fighting the unfavourable drive shaft angle and high engine and fuel tank weights.

 

[Osprey]

I installed drop fins on my R27 without removing the tabs. Just used a hand electric drill with a bit designed for hard metal. The fin was held in place with a clamp and use a template to get the hole in the correct location. The tab metal is fairly easy to drill through.

 

[scross]

I installed my drop fins without removing the trim tabs as well. The drop fins come predrilled for the four holes on each fin which served as a template. Just used several extra large spring clamps to hold each fin in place for drilling the first two holes. A cobalt drill bit at slower RPM makes short work on drilling.
Still waiting delivery of my trim tab spacers from Bennett Marine to eliminate the negative angle on the trim tabs and get the tabs parallel to the hull in the “up” position.

 

[j&lgray]

Update:

Installed the drop fins when I pulled the Ranger 27 to change the prop shaft anode. Whole job took about 90 minutes. I immediately found that the trim tabs were more responsive. I did not have to fully tilt the tabs to get the trim I wanted. There was a tad more speed and a bit better fuel economy. My main reason was to compensate for the heavy transom when carrying people, cargo or a dinghy.