looks like torque roll causing this?

[JPriami]

This mornings test was a little inconclusive. First few mins of it looked better. The boat wasn't chining as much. I was able to hold WOT and make some decent passes. Then noticed the boat wasnt tracking straight and had to adjust the rudder trim to fix( I'm guessing because the force exserted on the hull isn't in the center line of the hull). After that it seemed to want to torque roll over on it side worse at low/mid speeds. But would still go ok at wot. Then there was a drive line failure. at first i thought it was lvc. But the boat wasn't moving. Then thought I lost a prop because i could still steer the boat. Sent out the rescue boat to get her back. Found out the collet started to slip on the shaft. It was pretty tight in there too odd how it lost the bite.
I think I'm going to move the strut & stuffing tube back over to center of the hull but keep it up a bit from the stock location.
Gps recorded 55.4mph on this run.

[Fluid]

Ive also heard that moving it up will cause problems because not as much water will be getting to the prop.

That statement was made by someone who does not have much experience with surface drive setups and has a poor understanding of them. Right now the hull is riding too high because it is riding largely on the prop. To settle the hull down into the water to reduce chine walk you need to raise the prop. The hull will ride lower but plenty of water will still get to the prop. Heck, the whole idea is to reduce the amount of water going to the prop!

Sorry you are getting wore out by the Spartan, but it is sometimes difficult ot impossible to turn a sow's ear into a silk purse.


.

[JPriami]

That's true Jay about turning it into something it not. I just want it to at least be a better one that how it came. I'm not giving up yet. But I know in the end it won't be a gem. Just better. Btw thanks for the help.

Honestly im ready to start my next project (just want to finish this one up first). Building a cat little larger than the one i have now with twins.

[Greg Schweers]

The next thing I would try - bending the outside corners down on the trim tabs a little bit to see if that helps. For an example: I ran my new Insame mono last week for the first time, and I also ran the stub shaft .400 thousanths above the bottom of the boat. I always backcut the props on my mono. With the first set of batteries I ran, the boat was chime-walking really bad. The next set of batteries, I turned the outside screw on the righthand trim tab down a 1/16" and the boat was perfect. The only time I've ever run the strut level with the bottom of the boat was in N-1 class, because you want the boat to run as loose as possible. All the guys in our club that run the SV-27 bend the trim tabs down in the corners to help limit chime-walking.

[JPriami]

That's a good tip. And trust me I tried that first. No dice. I've also tried various configs on battery and weight placement. I've gotten real close but in the end it will chine at WOT to some degree. I have gotten it to go away but only with the help of water conditions. it was med chop those times. I want it to be versatile and still run all out on smooth water as well as chop.

Okay i just re-read what u said. U bent the outside corners of the trim tabs down? I haven't tried that. Or are you reffering to adjusting them down with the set screw?

[Brushless55]

The next thing I would try - bending the outside corners down on the trim tabs a little bit to see if that helps. For an example: I ran my new Insame mono last week for the first time, and I also ran the stub shaft .400 thousanths above the bottom of the boat. I always backcut the props on my mono. With the first set of batteries I ran, the boat was chime-walking really bad. The next set of batteries, I turned the outside screw on the righthand trim tab down a 1/16" and the boat was perfect. The only time I've ever run the strut level with the bottom of the boat was in N-1 class, because you want the boat to run as loose as possible. All the guys in our club that run the SV-27 bend the trim tabs down in the corners to help limit chime-walking.

can you post a picture?
I'm trying to follow what you did
thanks

[Greg Schweers]

I don't have a picture, but if you pm Darin, I'm sure he has a pic of his SV-27 with this done to it. You just bend the corner of the trim tab on a 45 degree angle, probably about 5/16" in, using a pair of pliers.

[JPriami]

moved back over towards center but still a little higher than stock.

[chummer]

Here is Darrin's pic. This is what Greg is trying to describe. However, I think you will have to move the trim tabs inwards a little to take advantage of this.

[JPriami]

moved it back but up 1/8 from stock location. hope I can test it soon. covered up with work lately

[Brushless55]

Oh man!
I totally forgot about what your trying here.. let us know how it works man!!

[JPriami]

Ive been busy with work, and in the hospital one day and down over the weekend. now back busy with work.

[Brushless55]

Ive been busy with work, and in the hospital one day and down over the weekend. now back busy with work.

you ok??

[JPriami]

Having kidney stone issues. My first time. Seems to be dragging along too. Might have to go back to see a doc.

[Brushless55]

Having kidney stone issues. My first time. Seems to be dragging along too. Might have to go back to see a doc.

sorry to hear this!
I'll be praying for you

[dag-nabit]

sorry to hear this!
I'll be praying for you

Take care of yourself, health and family first.

Kevin

[JPriami]

Thanks guys.
I might see is I can run at lunch today. Rain coming in tho.

[chummer]

Take care of yourself. I have never had stones but I do know plenty of people that have had them and it sounds very painfull.

Keep this thread updated when you get a chance. I am very interested to see what can be done with this hull.

[shctexas]

Will wider (2 1/4) trim tabs stabilize the boat?

[JPriami]

Ive been wondering about this with the trim tabs. If someone has them I'd say give it a try just to find out if it helps or hurts. because I hear some say and reading that you need two sets of trim tabs on a vee. the outter set are for cornering & the inner set are for ride attitude and fine tuning. But I also hear some say and read that a good boat doesn't even need trim tabs.
So just to put caution to the wind and find out by trial and error. maybe they will or wont. Lets find out.

[shctexas]

Well, I have a set coming. On mounting them, shouldn't they be flush with the bottom of the hull? The stock spartan tabs are slightly above the bottom of the hull. Should they be centered between the strut drive and turn fins or biased one way or the other?

[JPriami]

It's to my understanding that trim tabs should be just a little above the bottom of the hull. So how they are on the Spartan is correct to my knowledge. I had that same question. But I did a bunch of reading and even reading on real vee hull setups with trim tabs. And even on a real vee hull it's recommended that the trim tabs be about 1/2" or more above the bottom of the hull. So on scale that would just be a little bit on an rc but looks about right on the Spartan. It has something to do with the fact that your just using the back edges of the tabs for correction. I won't go into grave detail.

[martin]

The tabs need to be above the bottom. Thanks.

[dag-nabit]

Ive been wondering about this with the trim tabs. If someone has them I'd say give it a try just to find out if it helps or hurts. because I hear some say and reading that you need two sets of trim tabs on a vee. the outter set are for cornering & the inner set are for ride attitude and fine tuning. But I also hear some say and read that a good boat doesn't even need trim tabs.
So just to put caution to the wind and find out by trial and error. maybe they will or wont. Lets find out.

'nuff said??
Kevin



As JP has already pointed out, there are differing opinions on trim tabs.

I read one opinion on the spartan, that because the vee is so deep when it comes onto plane at high speed it will be high enough out of the water the stock trim tabs will be running basically dry.

This individual suggested a second set of tabs closer to the strut would help provided stability when the hull is high out of the water.

If you look inside the hull you will see there are specific moldings in the plastic designed to hold mounting screws coming through the transom. It might be advisable to try to utilize those mounting points if at all possible.

JP had posted a photo of them early.

Kevin

[shctexas]

Yep, i recall the posts and photos. I've identified the tabs and it's going to be a tight fit. I won't know for sure until I have them in my hand. Thanks for the input.