? for Mr John Finch on Wildthing trim tabs +turn fins

[riggerman]

Hi im in the process of builing the Wildthing mono to set up with electric brushless motor my ? I noticed on the stern view of the plan that both trim tabs and both turn fins are mounted fairly close to the keel .What are the advantages of having tabs and fins closer to the keel? I have been always advised to keep turn fins and trim tabs as close as possible to the outer chines.Regards Andris Golts.

 

[hugh hargett]

closer in they affect the ride in the straights wider out they affect the ride more when turning; I THINK :huh: You definitely want to leave enough space in between them to get whatever prop you may use between them. Most also mount them a 1/16th or 1/8th above the bottom edge of the transom. Got any photos?

 

[julianconde]

I has a wildthing just sitting here collecting dust I you are interested I can send you pictures.

Julian

 

[John Finch]

Anything closer than an inch and you will see the boat track left or right and not track straight. I like 1and 1/8th to 1 and 1/4 inch from the keel. This boat does not need an outside tab. Outside tabs make the keel dig in the corners for sharper turning. Not needed with the wild thing. Turn fins further to the chine make the boat bank more. Again, not needed with the wild thing. An inch from the side of the boat works fine.

John

 

[toyotatruckin]

I could almost bet that I was the last person to fully set-up and run JC's wildthing and can tell you exactily the good and bad on it ---run it JC--- DO IT!

 

[riggerman]

Thanks to all for repling to my post. Regards Andris Golts.

 

[Ron Olson]

John's Wild Thing .12 really doesn't need trim tabs or a turn fin if set up properly. One of my local boating bud's, Dave Homer built one and for trimming it we used one of John's tricks, a bead of medium CA along the very rear of the bottom. It actually made a noticable difference not to mention the money that was saved.

My little Wild Thing .12 built by Grimmie many years ago never needed either of the above. It needs a flat bottom and the CG in the right place.

 

[John Finch]

Ron,

You are so right! The ca trick works great doesn't it. I'm glad someone else has mastered it. That's how I trim my boats for record trials. Tabs are a 5 to 8 mph added drag when you are looking for all out speed.

John

 

[Ron Olson]

John, it's amazing as to how well it works and shows you also how important that last 1/4" or so the of hull bottom is in tuning any boat.

I suppose that we ought to give Steve Speas a little credit also.

 

[toyotatruckin]

RON I have good eyes and even I had to get close and squint to read that--font size 14 buddy lol

 

[Ron Olson]

Better Mike?

I'm wearing just my old bifocals and need a new set of trifocals and even I can sorta read it! This site picked the font size, not me.

 

[toyotatruckin]

lol

 

[Darin Jordan]

I respect the opinions of the Nitro guys who have run the Wild Thing hulls for decades, but I have been running Wild Thing hulls for FE for a few years now, and, after trying them without strakes, fins, or tabs, I run all my hulls with all three these days. My latest gained 3mph (with a VERY mild ROAR legal power system) by adding the trim-tabs and strakes (SAW Time-Trials)...

I have three 22" Wild Thing hulls, all with different strake configs. Strakes depend on the power being used and the finished weight. For my lower powered setups, I run strakes down closer to the keel. For higher powered, higher speed setups, higher up, the goal being to keep JUST the right amount of keel in the water at speed to retain control.

I place the trim-tabs to have the lower edge JUST about in line with the lowest strake. I only use the tabs to help balance the boat at speed and to control any chine-walking tendencies. Usually takes just a LITTLE bit. This is likely similar to using a beat of CA on the bottom, the effect being to provide a little more lift on the appropriate side of the hull to counter the prop torque.

I've attached a pic of my Time-Trial boats... The left one (white/silver) is setup for higher power, with a single strake, running parallel to the keel, about 1" up from the keel. This boat races at speeds over 40mph. (Current NAMBA SAW M2-Mono record holder at 41.something)

The center boat (wood finish) has three VERY small width strakes, evenly spaced, with the lowest being only about 1/2" up from the keel. This boat works very well with an N1 Power system.... ROAR legal BL motor on 2S Lipo... top speed around 40mph. (Current NAMBA SAW record holder for N1-Mono at 38.something... and 2-Lap record holder as well)

I get the boat as close as I can without using the tabs, then dial them in to get the finishing touch. Seems to work for me...

 

[David Bryant]

I respect the opinions of the Nitro guys who have run the Wild Thing hulls for decades, but I have been running Wild Thing hulls for FE for a few years now, and, after trying them without strakes, fins, or tabs, I run all my hulls with all three these days. My latest gained 3mph (with a VERY mild ROAR legal power system) by adding the trim-tabs and strakes (SAW Time-Trials)...

I have three 22" Wild Thing hulls, all with different strake configs. Strakes depend on the power being used and the finished weight. For my lower powered setups, I run strakes down closer to the keel. For higher powered, higher speed setups, higher up, the goal being to keep JUST the right amount of keel in the water at speed to retain control.

I place the trim-tabs to have the lower edge JUST about in line with the lowest strake. I only use the tabs to help balance the boat at speed and to control any chine-walking tendencies. Usually takes just a LITTLE bit. This is likely similar to using a beat of CA on the bottom, the effect being to provide a little more lift on the appropriate side of the hull to counter the prop torque.

I've attached a pic of my Time-Trial boats... The left one (white/silver) is setup for higher power, with a single strake, running parallel to the keel, about 1" up from the keel. This boat races at speeds over 40mph. (Current NAMBA SAW M2-Mono record holder at 41.something)

The center boat (wood finish) has three VERY small width strakes, evenly spaced, with the lowest being only about 1/2" up from the keel. This boat works very well with an N1 Power system.... ROAR legal BL motor on 2S Lipo... top speed around 40mph. (Current NAMBA SAW record holder for N1-Mono at 38.something... and 2-Lap record holder as well)

I get the boat as close as I can without using the tabs, then dial them in to get the finishing touch. Seems to work for me...

very cool, thanks. I run similiar straked hull (as the image on right) but 40 inches using .45 engine. Very fast and smooth handling. I've found that I prefer running conventional sub-surface drive (strut set approx. 5/8in deep), seems to operate more stable in turns.

 

[John Finch]

John, it's amazing as to how well it works and shows you also how important that last 1/4" or so the of hull bottom is in tuning any boat.

I suppose that we ought to give Steve Speas a little credit also.

Yes, Steve gets credit for that too. He is the one who mistakenly let the cyanacrolate drip under the hull while we were testing the day we found out how it worked. Steve and I have learned a lot together and much of it by mistake. It's learning from the mistakes that matters most. He is a smart person and sometimes sees things most people miss.

 

[John Finch]

I respect the opinions of the Nitro guys who have run the Wild Thing hulls for decades, but I have been running Wild Thing hulls for FE for a few years now, and, after trying them without strakes, fins, or tabs, I run all my hulls with all three these days. My latest gained 3mph (with a VERY mild ROAR legal power system) by adding the trim-tabs and strakes (SAW Time-Trials)...

I have three 22" Wild Thing hulls, all with different strake configs. Strakes depend on the power being used and the finished weight. For my lower powered setups, I run strakes down closer to the keel. For higher powered, higher speed setups, higher up, the goal being to keep JUST the right amount of keel in the water at speed to retain control.

I place the trim-tabs to have the lower edge JUST about in line with the lowest strake. I only use the tabs to help balance the boat at speed and to control any chine-walking tendencies. Usually takes just a LITTLE bit. This is likely similar to using a beat of CA on the bottom, the effect being to provide a little more lift on the appropriate side of the hull to counter the prop torque.

I've attached a pic of my Time-Trial boats... The left one (white/silver) is setup for higher power, with a single strake, running parallel to the keel, about 1" up from the keel. This boat races at speeds over 40mph. (Current NAMBA SAW M2-Mono record holder at 41.something)

The center boat (wood finish) has three VERY small width strakes, evenly spaced, with the lowest being only about 1/2" up from the keel. This boat works very well with an N1 Power system.... ROAR legal BL motor on 2S Lipo... top speed around 40mph. (Current NAMBA SAW record holder for N1-Mono at 38.something... and 2-Lap record holder as well)

I get the boat as close as I can without using the tabs, then dial them in to get the finishing touch. Seems to work for me...

You get good control with the tabs. I just recently experimented with a gas mono that works better with the tabs because the boat is over powered and it's faster with the tabs because the boat is better controlled. When you get to running SAW with only an inch of the keel touching the water and the whole boat flying on top of the water the strakes and tabs will not help. Then you adjust the ride with the rudder and last 1/4 inch of the hull. That is when the boat gains another 8 mph. For heat racing without tabs you need a forward CG to keep the boat trimmed, but that also gives you the ever looming occasional stuff! I would rather give up a little speed, run the tabs, and not have a boat that stuffs. Drive it like you stole it!

 

[Michael Caruso]

I respect the opinions of the Nitro guys who have run the Wild Thing hulls for decades, but I have been running Wild Thing hulls for FE for a few years now, and, after trying them without strakes, fins, or tabs, I run all my hulls with all three these days. My latest gained 3mph (with a VERY mild ROAR legal power system) by adding the trim-tabs and strakes (SAW Time-Trials)...

I have three 22" Wild Thing hulls, all with different strake configs. Strakes depend on the power being used and the finished weight. For my lower powered setups, I run strakes down closer to the keel. For higher powered, higher speed setups, higher up, the goal being to keep JUST the right amount of keel in the water at speed to retain control.

I place the trim-tabs to have the lower edge JUST about in line with the lowest strake. I only use the tabs to help balance the boat at speed and to control any chine-walking tendencies. Usually takes just a LITTLE bit. This is likely similar to using a beat of CA on the bottom, the effect being to provide a little more lift on the appropriate side of the hull to counter the prop torque.

I've attached a pic of my Time-Trial boats... The left one (white/silver) is setup for higher power, with a single strake, running parallel to the keel, about 1" up from the keel. This boat races at speeds over 40mph. (Current NAMBA SAW M2-Mono record holder at 41.something)

The center boat (wood finish) has three VERY small width strakes, evenly spaced, with the lowest being only about 1/2" up from the keel. This boat works very well with an N1 Power system.... ROAR legal BL motor on 2S Lipo... top speed around 40mph. (Current NAMBA SAW record holder for N1-Mono at 38.something... and 2-Lap record holder as well)

I get the boat as close as I can without using the tabs, then dial them in to get the finishing touch. Seems to work for me...

Darin,

Thanks for sharing your hours of testing.

Mike Caruso

 

[Michael Caruso]

Anything closer than an inch and you will see the boat track left or right and not track straight. I like 1and 1/8th to 1 and 1/4 inch from the keel. This boat does not need an outside tab. Outside tabs make the keel dig in the corners for sharper turning. Not needed with the wild thing. Turn fins further to the chine make the boat bank more. Again, not needed with the wild thing. An inch from the side of the boat works fine.

John

Sorry John I ment JB from MI who's boat was called Lead Sled.

Hello John,

In the wayback time machine 1972-73 you raced your killer gear'd twin against Gene Klisnic's gear'd twin using HP.40 engine's in an Octura Wildcat .60 tunnel on a short 1/3 mile oval. Racing Dolphins club in IL. So glad to see that you are still having fun.

Mike Caruso