Dana W

Yes I have to agree when I had the smaller prop on it ( 280 ) the boat didn't prop walk as much . But because this boat is still at it's testing stages I want to see what it can handle . The M-6 can handle the big prop no problem and at full throttle the boat is off the water and as soon as I straighten the rudder the boat is like a rocket and very stable . That's what I've been waiting for . Now I just need to control the prop walk which I think I'm almost there . My idea of a drag boat is to stay in your own lane from 0-100 or from start to finish without giving it any rudder . I'll have to get me a 6717-3 from Dasboata and see what happens . Thanks for all your input guys .


Not to change the subject BUT my DaVette SS has the strut mounted right in the center and with a stock 260 Zenoah & a 275 prop it doesn't have prop walk ( at least not that I noticed ) That boat will take anything you throw at it . Very kid proof .

martno1fan

Thats what its all about mate trial and error see what works best,as for props just ask chris what he recomends ,but having a few props to test is the best way to find which one works best so keep testing and having fun.As regards your ss thats an awesome boat i really like the looks of it pitty shippings so high right now.
Mart

rcboateric

Believe it or not, your runner boat is fine of the current strut position and the rudder blade, I asumed the tracking problem is from your bigger prop, a big prop doesn't mean that will give you a big speed, opposite, it would slow down your boat and bring you lots of trouble, you might also consider a Chris mod round ear cup 2716 15* prop, this prop would run 75 mph on my sprint cat and it'd also run fast for a mono and rigger, once you use a correct prop, the trouble will go away. here's an another method, kick in your tapered blade about 15 degree to the transom side, your runner will track more straight.

Dana W

Well so far the bigger prop has given me the most speed but at the same time most trouble . I agree it's a matter of finding the best prop but that can also run into the $$$ . I'll try this one more test with the new strut then i'll start playing with different props . I did try a Voodoo 6717-3 and it just dug a hole . The right prop has to launch the boat out of the hole and stay straight for 264 feet . When I accomplish that I'll be happy .

martno1fan

Dana my 6717/3 is similar in that it was slower on takeoff but once you gave a bit more throttle it took hold and the speed was very good,on the hydro it runs better not as much slip etc that said i orriginally had it in a vee with a clutch which would maybe explain the slip in fact im sure it does.Outa the hole i found the x472 prop pretty good even on a stocker but it was a tad slower on top end speed.You can but try mate ,3 blade props do tend to take longer to get going though so if its acceleration outa the hole you want maybe a 2 blader would be a better choice?.I would say the big prop would be much slower on takeoff and if its a drag race it could be over before it gets up to speed ?.Im sure Chris can help you out just give him a call or email him.If you watch my hydro videos froma standing start you can see how when i give a bit more throttle she suddenly takes off like a bat out of hell ,very fun to say the least .Try a few more props see how you go im sure you will get her running how you want in the end.
Mart

rcboateric

I just found a outside thread that was talking about his X482 prop that how hard to pull his boat to the right, check your PM for that link.

martno1fan

The x482 is a good prop for a weedy motor i wouldnt run it on a modded zenoah my self nor the 280 prather either without some serrious mods.That said i know the guys running the big sikk love the bigger props as its a lower revving motor but has lots of torque.
Mart

rcboateric

A big size prop does not mean the big speed to me, I did try a 2716 and a 2916 prop on my cat, the first one beat the second one by 6-7mph.

Dana W

did I mention that my 482 was modified by Dasboata ? The next video I'll show take off .

martno1fan

Nice one any idea what mods hes done,back cut ,rounded ears ,cupped? all 3 probably .Come to think of it i did read about this prop somewhere probably on another site lol.Keep us posted im loooking forward to seeing some more video of this one.
Mart

Dana W

Well I tested it again with the strut off set to the right 1/4" and there was no difference . I also tilted the rudder in and no difference . It still walks to the right . I received the new strut from Billy ( Top Secret Boats ) and noticed it was off set to the left . I didn't install it because you guys said to go to the right . I tried to get ahold of him but he';s not answering his phone . ( it's after hours probably ) I'm thinking about off setting the strut to the left 1/4 " from center and see what happens .

rcboateric

You should stop drilling holes on your boat, I told you it won't work but you just didn't believe me, all the problems are coming from your prop, Have you received your mod(round tip back cut) 6717 prop yet?

Dana W

LOL nope , didn't order one .

Paul M

Dana,

I think the Top secret strut is ANGLED to the left which would push the transom right to counteract the prop walk. But I agree that your tracking issues have to do with the prop as well. I am fighting the same problem with my drag cat. Give it a shot. I have had problems shimming my struts as at high speed the boat jumps left when I let off the gas. I don't think it would be a problem with the Davette but with the drag cat at 65 mph it definitely was. Chris tells me he shimmed his and did not have the same problem, but he's probably a better driver than me

The Davette is running better and better everytime I see it

Good Luck

martno1fan

Props too big mate as i said before as for the offseting to the right it does work but you have two major things working against it ,first your massive oversized in my opinion prop and that picckup hanging below the transom Drag drag drag get the idea .Also been a flat bottomed boat (apart from the runners) ie no vee i would think prop walk could be a difficult thing to overcome as the boat will slide very easyly compared to other boats.Ive ran 5 differnet monos with offset setups and none of them veer right they all track straight,drop a few sizes on your prop piccup a few rpm and your boat will track straighter.Another thing you might try is a subsurface setup which might suit that boat better than surface drive,less prop walk on that setup.If you stick with surface drive you might try the prop eric suggested its a good prop for a mono but id maybe go even smaller myself.
Mart

Dana W

nope , I'm not going smaller yet . Call be stubbarn if you must but I'm headed back out there now . I'm keeping the strut off set to the right and I added a anti-skid fin on the portside . If that doesn't work I'm going to shim the strut on the right just a tad . I'm not going to pull the water pick up just yet .

martno1fan

STUBBORN LOL !!just kidding mate hey go for it theres more than one way to skin a cat as they say , i dont like been told what to do or that im wrong either yes i am stubborn too .Im sure you will find what works for you just keep playing mate.
Mart

MrMikeG

If you want a great launch with an in-expensive prop try a X470/3 blade. The extra blade gives you more surface area than what your running now! For less prop walk with what you have reduce the diameter on the 482, I can't believe Chris didn't already do that for you! 3014's launch good too!

rcboateric

Shimming a strut did not work for me too, hey Pull, 65 mph of your drag cat, that was screamingggggggg..

Dana W

Well I'm back from the pond and I have to say the anti-skid fin ( turn fin ) on the left made a big difference . Still had to add alittle left rudder .Shimming the strut made no difference . So OK I'll talk to Chris ( Dasboata ) on Monday and see what he recommends . I don't mind going to a subsurface set up with a smaller prop and more pitch .

martno1fan

If you dont mind doing prop mods yourself just reduce its diam a bit round off the tips more or send it to chris and have him do it.You can also remove some tongue off the prop to allow it to spin easier as it reduces blade area ,Chiris is def the man to ask though so maybe just ask him what he recomends and explain what problems your having now.Mikes idea sounds good too the x470 2 blade was a great prop on my stocker so i would think the extra blade of the 3 blader on your modded motor would work really well.Sounds like your going in the right direction though so just keep playing and trying different props till you find the results you want.
Mart

Dana W

I talked to a good racer friend of mine in Medford , Ore and he said the same thing " I need to go sub-surface with a smaller / more pitch prop " . So this week I'll get the boat ready for sub-surface drive , keep the water pick up's in the rudder only & plug all the unnecessary holes in the transom .

martno1fan

Why not try the prop change first before you change everything else.

rcboateric

If a prop has too much pitch on it and your engine can't unload it, the prop would create the prop walk, your best bet is lend a mid size and pitch prop from other boaters and try it first before you order it.

Dana W

Because this last time I was out I tried a few different props that I had on hand 275 Texas Cut & a 280 stock and I still had to give it left rudder to keep it straight . On another runner bottom I have it set up as sub-surface drive and it tracked pretty good but I modified the bottom to get less wet surface . Now I have less wet surface but more prop walking . I'll get it figured out . I'm almost there .