Best set-up for best cornering speed

[John Finch]

Right on!

John

 

[mtruex]

My thoughts on fin placement. Not saying you are all wrong , but my boats balance point resides on the turnfin with no fuel. Roughly around the rear 1/3 mark to tip w no fuel. I don't like the fin too far forward, I feel it just makes the boat darty on entry but does not turn any better at apex to corner exit. I don't think it changes the turn speed as much as the feel of the boat, at least for me. If the boat pushes I work on the fin size / curl/ depth. Just a few of my thoughts.

 

[Jerry Dunlap]

My thoughts on fin placement. Not saying you are all wrong , but my boats balance point resides on the turnfin with no fuel. Roughly around the rear 1/3 mark to tip w no fuel. I don't like the fin too far forward, I feel it just makes the boat darty on entry but does not turn any better at apex to corner exit. I don't think it changes the turn speed as much as the feel of the boat, at least for me. If the boat pushes I work on the fin size / curl/ depth. Just a few of my thoughts.

When rain washes out practice time, provides an opportunity to consider other interests.

Jerry

 

[Grimracer]

I have found massive gains in corner speed though chine rise angle and chine approach angle.

I personally hate a darty boat. I personally don't want a boat that feels like it requires correction in the straightaways. I am more then glad to drop MPH to gain handling.

Your results may vary.

Grim

 

[John Finch]

Martin,

Congratulations on breaking the D,E, and F oval records recently. You just told everyone where your turn fin was in relation to the CG so there is the proof where the fin should be for the fastest turn. Post answered!

John

 

[mtruex]

Thanks John!

That's what works for me on my boats and my driving style at least! Always more to try!

 

[dwilfong]

Martin

Do you think about this when you are stuck in the 200MPH traffic jam?

Seriously do you day dream about RC boats when racing?

I won't tell any one............

 

[timothy johnson]

David, Martin is all about boats on here and all about NASCAR at work. He keeps them separate!!!!

 

[John Beardslee]

Thanks John!

That's what works for me on my boats and my driving style at least! Always more to try!

As always there is more than one way to remove the epidermis of the feline creature, if you are working to do the best times on an oval then a set up for one boat on the course is the priority and that's for sure what Martin has. Now lets mix in the race water factor and now the non trip comes into play as well as the fore and aft angle of the notrip. Isn't this fun, not just a matter of re-surfacing the race surface but a truly variable changing track condition is what I most appreciate of the "Betke boats I run. These things boats really perform in race/ruffwater conditions! Thanks, Jerry & Mike Betke - soon to follow Rob Betke! No one runs their boats better than Rob.

Thanks, Johh

 

[Marty Davis]

When I used to run the nitro boats years ago I would set my needle valve a bit on the rich side to make the boat run faster in the turns. It was an obvious change in speed through the turns as the extra load naturally leans out the engine. Just an engine related effect to consider. Basically setting the needle for the turns and not the SAW. Longer pipe length is another turn speed helper. You might lose some SAW speed but we all know it is the fastest lap that wins, not the fastest SAW speed.

John

With the new radios, we can do that with mixing the rudder and tyhe mixture control. I do that on all my boats.

 

[Andy Greene]

When I used to run the nitro boats years ago I would set my needle valve a bit on the rich side to make the boat run faster in the turns. It was an obvious change in speed through the turns as the extra load naturally leans out the engine. Just an engine related effect to consider. Basically setting the needle for the turns and not the SAW. Longer pipe length is another turn speed helper. You might lose some SAW speed but we all know it is the fastest lap that wins, not the fastest SAW speed.

John

With the new radios, we can do that with mixing the rudder and tyhe mixture control. I do that on all my boats.

I started doing that a few years back on my 40 mono and scale- dependant on boat it may take 2 clicks

- i click up on mixture (needle dependant) when right input was applied- boat held rpms all the way thru the corner, with the Scale it was 2 clicks

 

[Mike Betke]

Thanks John!

That's what works for me on my boats and my driving style at least! Always more to try!

As always there is more than one way to remove the epidermis of the feline creature, if you are working to do the best times on an oval then a set up for one boat on the course is the priority and that's for sure what Martin has. Now lets mix in the race water factor and now the non trip comes into play as well as the fore and aft angle of the notrip. Isn't this fun, not just a matter of re-surfacing the race surface but a truly variable changing track condition is what I most appreciate of the "Betke boats I run. These things boats really perform in race/ruffwater conditions! Thanks, Jerry & Mike Betke - soon to follow Rob Betke! No one runs their boats better than Rob.
Thanks, Johh

Thanks John. Yes, with all the theory put there on this topic what makes our turn fin sponson desighn combo turn so well.

 

[Mike Betke]

My thoughts on fin placement. Not saying you are all wrong , but my boats balance point resides on the turnfin with no fuel. Roughly around the rear 1/3 mark to tip w no fuel. I don't like the fin too far forward, I feel it just makes the boat darty on entry but does not turn any better at apex to corner exit. I don't think it changes the turn speed as much as the feel of the boat, at least for me. If the boat pushes I work on the fin size / curl/ depth. Just a few of my thoughts.

Well Martin's thoughts are in line with a lot of what I have experienced, even though the boats we run are totally different. I have found that as you move the fin forward toward the ride surface of the sponson, it will plant that sponson in the water more as it goes around the turn and suck that side of the boat down and have it go thru the turn with a quicker response (dart thru the corner) not necessarily faster as Martin has proven . As you get the fin in front of the ride surface of the sponson, that darty condition gets worse as it plants more of the ride surface of that sponson in the water. I set my 20 boat up like this as a test and the boat darted so fast in the turns I could not stand driving it in heat race conditions. Some people like a set up like this, but I personally don't, especially for heat racing as water conditions during heat racing can cause a darty boat to react the way you do not want it to. The set up that we have been running for years with the anhedral sponson and turn fin on the outside utilizes the fin to pull down the sponson and plant the entire boat down thru the turn instead of pivoting on the turn fin and the outside sponson. I went back to that on my 20 and it turned better with no darty tendencies at all. It works for us and our driving style.

I have not always put a lot of thought into C/G relationship to the turn fin in a free state. There are way to many other factors when the boat is being thrust forward involving prop type, shaft angle, sponson design and attack angle, ski or rear sponson design, hull bottom shape that factor into how the boat rides and turns at speed. It is a good way to benchmark measure where you need to be once you get your boat set up right, but in my opinion you need to get there first. Weight distribution can be a factor, but there are many others factors to look at as well. Look at all the different boats out there and how different the relationships are and they all turn very well.

 

[stan simpson iv]

Thanks John!

That's what works for me on my boats and my driving style at least! Always more to try!

As always there is more than one way to remove the epidermis of the feline creature, if you are working to do the best times on an oval then a set up for one boat on the course is the priority and that's for sure what Martin has. Now lets mix in the race water factor and now the non trip comes into play as well as the fore and aft angle of the notrip. Isn't this fun, not just a matter of re-surfacing the race surface but a truly variable changing track condition is what I most appreciate of the "Betke boats I run. These things boats really perform in race/ruffwater conditions! Thanks, Jerry & Mike Betke - soon to follow Rob Betke! No one runs their boats better than Rob.

Thanks, Johh

John are you planning on racing at the Twin Shootout in March?

 

[John Beardslee]

Hi Stan

It's on the calendar and I'm registered, good lord willing I'll be there.

Thanks John

 

[John Finch]

Mike,

I run the turn fin on the back of my sponson on my "scrap Lumber" boat much like yours and the fin shape is very similar to yours as well. I run anhedral on the left side of the right sponson and dihedral on the right half of the sponson. Did it by mistake while adding a new surface on the sponson bottom. Don't know if it is a good or bad thing but the boat is awesome in the corners.

John F.

 

[Lennard Cuenco]

I have found massive gains in corner speed though chine rise angle and chine approach angle.

I personally hate a darty boat. I personally don't want a boat that feels like it requires correction in the straightaways. I am more then glad to drop MPH to gain handling.

Your results may vary.

Grim

chine 'approach angle' Mike? what is that?

 

[JRXHydros]

I have found massive gains in corner speed though chine rise angle and chine approach angle.

So glad I don't have to worry about angles,I'm flat as a pancake & rippin the corners up! It's like don't worry be happy.

 

[Grimracer]

note.. I did not say angle was necessary.. or even wanted... ROCK AND ROLL!

Thinking....So.. flat as a pancake means you have 0 deg AOA?

Thanks

Grim

 

[JRXHydros]

note.. I did not say angle was necessary.. or even wanted... ROCK AND ROLL!

Thinking....So.. flat as a pancake means you have 0 deg AOA?

Thanks

Grim

its all good Grim...yes I have AOA on front & rear sponsons. I was eating blue berry pancakes & I guess it was on my mind when typing. So anyway flats for me & worry free.