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Trim Tabs on a VTX


rakr

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Ill head off the, "Just by a TXi" comments. I might look at one in a number of years, but right now the v-drive layout and higher freeboard is better for 80% of what we do. I know by adding tabs I won't get a TXi like wake.

I am thinking of putting some Bennett hydraulic tabs on my 2013 VTX to improve the slalom wakes. Right now ill ski at 34mph and 28 or 32 off, and the Slalom wake is ok, but I am pretty certain it could be better. In reading posts from Team Talk, and BOS, it seems that there could be a noticeable improvement. I am thinking about doing this in combination with some other weight reduction exercises, and have even considered removing the tower to save weight (and make it easier to get in and out of the garage), but removing the tower brings all sorts of other problems to solve. The couple of features on the new SN (Hydro-Gate and MicroTuners) got me thinking about adding tabs.

I am thinking the tabs are relatively low risk, if they make the wake worse, or don't make a noticeable difference, I am out $800, but can probably sell the kit on ebay, and spend a bit of money to have the gel repaired. BOAT...

https://www.amazon.com/Bennett-129atp-Hydraulic-Trim-Complete/dp/B07G7ZPGNM

1. Has anyone on here added tabs to improve slalom wakes?

2. For the folks that have after market tabs for surfing, if you put them down a touch while slaloming, is there a noticeable improvement in the slalom wake?

3. Does anyone have thoughts on placement, or possibly shape modifications that might be good for the 12x9 tabs. My schoolin' in hydrodynamics is a bit lacking. I have no idea what it will do to the trough, wake height, firmness etc. we will see!

4. Any thoughts on electric vs. hydraulic?

Thanks crew!

 

Edited by rakr
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Others with much more experience will no doubt reply, but you mention slalom wake and surf wake.  The surf wake could be improved with appropriate ballast and tabs on the sides (surf gates) of the boat (not the bottom) to skew the hull.

For the slalom wake, I'm not sure you can get much better.  I think I would start with trying some weight in the bow, and consider trying different line lengths to find the best wake for your speed.

But like I said, others have much more experience than I do with this.

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I'd imagine tabs won't help your slalom wake at all unless you can get a Tige-like TAPS setup that goes across the entire transom, effectively allowing you to tune the "hook" of the hull.  If you don't, each individual tab will have its own "wake" that the main wake will stack on top of.

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40 minutes ago, UWSkier said:

I'd imagine tabs won't help your slalom wake at all unless you can get a Tige-like TAPS setup that goes across the entire transom, effectively allowing you to tune the "hook" of the hull.  If you don't, each individual tab will have its own "wake" that the main wake will stack on top of.

thats a bit of what I was afraid of happening. One of the threads on BOS mentioned “the hook” and recommended building it with some epoxy. 

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12 minutes ago, rakr said:

building it with some epoxy.

I am gonna file this the Patently Bad Idea category.  You need to really understand hull design, fluids, etc. to not totally pooch things.  Look at some of the interesting things on hull design like chine lock, etc. and they were purportedly from people who do this as a day job.

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1 hour ago, Eagleboy99 said:

I am gonna file this the Patently Bad Idea category.  You need to really understand hull design, fluids, etc. to not totally pooch things.  Look at some of the interesting things on hull design like chine lock, etc. and they were purportedly from people who do this as a day job.

That would be at the bottom of my list. IIRC One guy said he created the hook with some “caulk” to give it a try and he said a minimal amount of hook made a difference and he ended up pulling the caulk off and putting epoxy down.

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34, 28-32 off using the center pylon, Bow filled. I watched the videos of you skiing those speeds/lengths on your VTX. My wakes look pretty similar, maybe a bit bigger but not much. 
 

My cousin has a NXT up in TC with the 3 tabs. he said the ski wake is better than he would have imagined and the tabs help a lot. I’m going to head up there (once we can officially get out of the house) to take a look at what outer tabs do to the wake. 
 

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ahopkins22LSV

Have you tried without the bow filled? Honestly the wake should be better on your boat over our 19. No way it should be bigger. What prop are you running. Do you have any video or pictures?

Do you always have a huge group of people and gear? These boats are really weight sensitive especially for skiing. The less the better.

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1 hour ago, rakr said:

34, 28-32 off using the center pylon, Bow filled. I watched the videos of you skiing those speeds/lengths on your VTX. My wakes look pretty similar, maybe a bit bigger but not much. 
 

My cousin has a NXT up in TC with the 3 tabs. he said the ski wake is better than he would have imagined and the tabs help a lot. I’m going to head up there (once we can officially get out of the house) to take a look at what outer tabs do to the wake. 
 

I'd try skiing behind it yourself, that would be the first report I have ever seen saying that an NXT is very good to ski behind.  While I don't ski shortline I believe that the wake on my VTX is as good as my inlaws 04 LXI at 15 off once you get up to 32 MPH

Edited by oldjeep
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I dont know about the newer VTX, but my 07 has a better wake than my 99 Lxi.  Everyone that skis behind it cant believe it's a V-drive.  I dont fill any ballast, and only like to run driver with one passenger.

 

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2 hours ago, mrothwell said:

I dont know about the newer VTX, but my 07 has a better wake than my 99 Lxi.  Everyone that skis behind it cant believe it's a V-drive.  I dont fill any ballast, and only like to run driver with one passenger.

 

Not that I'm going to dump my RLx any time soon... but at what line lengths/speeds is the comparison being made.  I ski 34/32-35 off but the rest of the fam-jam... not quite.  More like 32 mph/15-22 off

 

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Thanks For the feedback. Maybe I am second guessing my direction. I’ll hold off until I get a bit more info and post some videos. 
 

1. I have tried no bow weight and it doesn’t seem to make that big of a difference. 
2. I’ll make sure to ski the NXT and maybe bring up my VTX and do a side by side. 
3. I’ll try to ski without people and take video once we are off lockdown. Right now I only have a video skiing in a bit of chop with 4 people in the boat. I have skied with only a driver and that is what I am basing my observations on. 

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22 hours ago, Eagleboy99 said:

Not that I'm going to dump my RLx any time soon... but at what line lengths/speeds is the comparison being made.  I ski 34/32-35 off but the rest of the fam-jam... not quite.  More like 32 mph/15-22 off

 

I ski at 34 mph, and tow people that like to ski closer to 32.  We all run at 15 off.

 

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@rakr I didn’t see it mentioned, what hull is on your VTX (wake or diamond)? 
 

I have a scarpa suppression plate (SSP) and have used it on my previous boat (2002 Sunsetter) and my current boat (2009 Response LXI). If your not familiar with the SSP, it’s a manually adjustable “trim tab” that attaches to the manual wedge bracket.  My experience with it is that at 32 MPH or higher it flattens the table between the wakes, makes the wake a tad smaller but firmer. Below 30 MPH it makes the wake smaller. 
 

So what does this all have to do with the VTX? Based on what I’ve observed using a central “trim tab” on boats that are slalom oriented, I think that you will find the expense and labor will result in a very marginal change for the speeds you are skiing. Slower speeds, if they are of interest, might benefit from them.  

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@Wayne Diamond hull, good question though, but to be 100% certain I will post pictures of the Hull along with the video of the slalom wake. When I was buying the boat, I asked the dealer to confirm with Malibu that it was a diamond hull, and he sent me a screen shot of the S# lookup.

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I test skied 2012 or 2013 VTXs with both hulls. If you try to cross a wake hull like your were skiing in a slalom course you will be airborne well past the second wake. Its easy to tell the difference, look at the back of the hull (transom) among the bottom edge as it meets the vertical sides. If there is a downward hook where the side meets the bottom it’s a diamond hull. If the angles of just come to a normal intersection it’s a wake hull. 
 

If it’s a wake hull there isn’t much you can do to improve the wake for skiing. If you have a diamond hull then I would focus on weight. Anything that is not needed take out of the boat, everything else move to the storage area under the spotters seat. Make sure all your ballast tanks are empty and keep the crew to a minimum. 

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We just traded our 2011 vtx, after 6 years. This is the only pic i have of the wake handy, 32 mph, not the best water. Front ballast full around 3/4. Me and my 12 and 13 yo boys were in the boat.  Probably 1/2 a tank of gas. 20190813_121308.thumb.jpg.f27e56a4561631ae9e4347ccc4f86152.jpg

while it was good to ski behind for a v-drive, our Lxi was far better. The VTX wake was soft, but the bump was bigger at 28 & 15 off, inside of that, especially at 34/36 mph, it was pretty good, though the trough seemed firmer the more weight in the boat.

One of my boys went to camp where they used 2019 NXT22's last year.  My son didn't even consider skiing while he was at camp after getting one look at the wake from the NXT. Even the camp owner said you could ski behind it, if you wanted to, but compared to the VTX, well you can if you want to.

As @Wayne mentioned above, when its time to ski, if its not actually required in the boat, take it out, especially extra people. Try more weight in the bow, and double check you speeds with gps, consider bumping up the speed a little. I think you will find it. An be pretty good.

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  • 4 weeks later...

Thanks for the replies. I should be getting the boat back in the next few days and can confirm the prop and hull, but again I am 99% sure it is the diamond hull (I do have the 3D sticker on the transom if that helps confirm as well) and I am betting it is the Acme 537 (I believe that was stock). I reached out to Eric @ OJ and he recommended WAKEPRO V-4 15 X 14 LH 1 1/8” 4-blade, #1951-MF, he said he would take it back if I didn't like it. I saw another post that seemed to confirm that a prop change could make a noticeable difference. to be a bit more clear on where the issue is, it is 100% the rooster tail. It seems gigantic. The rooster tail is pretty substantial from 22 to 32 off (I haven't tried 35...), 28 seems to be particularly bad. moving from the rear pylon to the center doesn't seem to make that much of a difference.

I have tried to remove all weight I can in the back, run with driver and observer only, and fill the bow ballast. I know the PNP bags that came with the boat never drain all the way, so 2-3 gal of water in each could make a difference. I am going to keep them out for my next set of "trials". Ill also try to remove everything I can from the boat in general, but particularly in the back.

The rooster tail on my wake is infinitely more pronounced than @snowman's pic above. I would love to have that wake. I could be exaggerating, but it seems that mine is 6-8" higher, and it feels like a kicker even when I am on edge and relatively balanced on the ski. There really isn't any "flat" between the two wakes.

I have tried to see if the wedge was dragging, and I seem to recall it does a touch. If it comes to it, Ill remove the wedge to see if that make a difference.

I hope to get a morning session here soon to be able to run through a bunch of different lengths and get some pictures.

Thanks all!!!

 

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2 hours ago, rakr said:

@snowman do you recall what prop you were running on your VTX?

We ran a 1273, which i have for sale. I chose that because it maintained the best higher speeds, while allowing heavily loaded surfing. We never experienced hitting a limit with the 1273.   

Also, if you have that 3D sticker, its a damond hull. Which is what we had.

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@snowman I might take you up on it. I want to wait to pull the trigger on anything until I get minen back and see what prop I have on there. I ultimately might buy a couple and see what is best and resell/return what doesn't work. I didn't see the 1273 listed in the classified (I might have missed it), do you want to PM me a price?

Thanks!

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4 hours ago, rakr said:

@snowman do you recall what prop you were running on your VTX?

"Stock" for skiing would have been a 1939.  It is what I run on my 2012.  The 537 is an older prop that would have been stock on the older vtx

Edited by oldjeep
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7 minutes ago, rakr said:

@snowman I might take you up on it. I want to wait to pull the trigger on anything until I get minen back and see what prop I have on there. I ultimately might buy a couple and see what is best and resell/return what doesn't work. I didn't see the 1273 listed in the classified (I might have missed it), do you want to PM me a price?

Thanks!

Pm sent.

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