Malibu RCB trunk delete

[escmanaze]

Also, I LOVE that you put the gas tank up front. To me, that is the most under-discussed and under-appreciated aspect of the new Nautique design is the better location of the gas tank as well as being able to fill it from both sides. In my opinion, that is really significant innovation that I can only hope the other manufacturers follow. For years we have literally picked the absolute WORST spot possible for our gas tanks on our ski boats.

[BlueSki]

@escmanaze My father in law had a 60’s tri-hull with an under helm gas tank to reduce draft for fishing shallows. It skied really well for an old outboard on open water.

[vtmecheng]

Really cool build. I bet the wakes are nice but tracking took a hit. Also, with a full tank and only two in the boat it probably wants to dunk the nose with even the smallest wake.

[robmollysilverlake]

@vtmecheng I get to drive his boat when he skis and I haven't noticed any problems with the tracking, we also usually ski in the morning so no surfers are out. We drive across the lake to get to the course and if it's windy the nose has never been close to dunking, but it's a closed bow anyways. Would be a different case if you were planning to bring your family out on the lake all day and there were big surf boats, but thankfully he doesn't have that problem since he has a couple other family boats, hopefully he'll post a picture of them too!

[MNshortliner]

I will have to post a ski video.

@DavidN Great looking Response, I’ve always loved red boats. What did you do to drop some weight? I did look through some of @DW builds from Malibucrew. He will have to chime in on tracking also. Don’t know why it would get worse as the rope connects right above the three tracking fins. The boat feels like it has a very good “Response” while driving.

@BlueSki I only skied it about 10 times last fall but I do remember a hard bump at 32 but it wasn’t very big. Now it barely feels like there is a wake. The only time I feel my ski jump at the wake is if I hit it flat after dropping into the trough. But there is almost no trough now also.

@escmanaze i really like how easy putting gas in this is now. I siphon my gas into all the boats. Put a towel down, put the can on the towel, put the hose in, squeeze the can, and just sit there for a minute.

@vtmecheng like @robmollysilverlake said this boat only gets used from about 7 to 8:30 in the mornings. Most of the time we literally have the lake to ourselves, but if you did come onto some rollers at 5mph or less you might get a free boat wash.

[Rednucleus]

Wondering if you would consider adopting a 62 yr old and try to pass on some your skills??! Very fine workmanship sir!

[ReallyGottaSki]

Double clamps on the fuel outlet, thoughtful!

 

Every tourny boat seems to respond positively to a diet, haven't heard the contrary yet.

Have long aimed to find an older rcb to hobby with in the next few years. Hopefully with a poorly winterized engine.

 

Finally scaled my dieted old supreme yesterday, 2380 with a full tank and two pair of skis under the deck. Skies quite good for it's vintage, and compared to its contemporaries.

[DW]

I have been very happy with my project, basically a pretty significant weight reduction effort (475 lbs so far) and have not seen any serious drawbacks. The tracking topic was a concern as I embarked on the project but tracking has actually improved and my theory on the reason, CG is moved forward putting more hull in the water and moving the actual pivot moment more over the fins. My boat has the water break farther forward than a typical Response, there are 3 on the lake so easy for me to compare. Wakes are really nice, very flat and the short line dip is also gone. It did not hurt the barefoot wake although I can't help comment on the trick wake or the wakeboard wake (fairly confident it sucks:-). A nice byproduct for me is the transom hole where the old tank went is now a ski locker and as been noted, the step over to the platform is very nice. Another humorous byproduct, my platform is much higher out of the water as I did not change the brackets:-) As for double clamping things, I also double clamp any water pressure line (raw water pump > circulation pump) and all the pressure fuel lines.

[VONMAN]

Great design and execution!! Love it when a plan comes together.

[MNshortliner]

This is a video of myself 34 mph 35 off.

 

https://www.dropbox.com/s/pq3f4cf1ougcxgm/trim.617103AE-C498-4F85-BD16-463F7F0278F4.MOV?dl=0

[vtmecheng]

That's really cool to improve essentially everything you want in the boat. Nice work and something to be proud of.

[MISkier]

Great video. Wake looks really nice. And, that is one tremendous spray leg sleeve you're wearing.

[MNshortliner]

@MISkier Thanks, yea I can tell you that leg never gets cold. Haha

[Zman]

@MNshortliner With that small wake you have now, don't you feel like you are cheating? LOL. Nice skiing!

[powbmps]

What wake? That is awesome.

[CR1]

Nice fab work! I understand everything except the swim platform. A) Why would you want to get ride of beautiful teak for industrial looking metal B) Why is is so far off the water? That's got to pose an unnecessary challenge to get back into the boat.

[ReallyGottaSki]

Hazard of a light boat...

 

[escmanaze]

Dude, that wake!!! That is the exact goal you were looking for. That is so cool!!!!

[DavidN]

@CR1

Boat came with a fiberglass platform. The whole purpose of @MNshortliner ’s modifications had been to reduce weight (mainly in the back of the boat) to flatten out the slalom wake.

Judging by the video, it seems he accomplished that goal with bravado.

The fiberglass swim steps that Malibu build are unnecessarily heavy (they weight more than the teak ones)!

That’s almost certainly the reason why he build his new platform.

If it had been my project, I would have sourced a Nautique fiberglass platform and had it mounted to the boat. They are super lightweight.

[MNshortliner]

@cr1 I didn’t have a teak platform and at the time my labor was cheap. I did wrap it with the EVA so if I didn’t tell you it was aluminum you would have never known. It isn’t any harder getting up on this platform than a water level one right now, but ask me in 20 years and I might have a different answer for you.

I have not skied any other newer boats so I don’t really have anything to compare it to but it is absolutely a non factor while skiing in the course.

@ReallyGottaSki nice Supreme. What year is that one. My neighbor just bought a ‘91 but I have not skied it yet.

[DW]

For those asking on wake effect of reducing weight, and particularly at the transom, on an older ski boat, it can / does improve the wake to the level of the newer offerings. Depends on how aggressive you want to get. That first hole is the hardest one to drill:-)

 

@CR1 - teak is gorgeous when taken care of, I made a lightweight carbon fiber platform to reduce weight at the transom. Is it as pretty, no although it does help the wake and takes no maintenance so for me a win.

[ReallyGottaSki]

@MNshortliner thanks!

It's an 82 that was a rescue, an abused turd that I polished. split at the rub rail to rebuild, and improved over the last 25 years, great slalom boat, minus the side spray ,that is still to be addressed. It will now get to 30 in 2.8 s and 40 in 4.6 seconds and with a clean bottom has topped as high as 51.5, it's a hoot.

 

It suits me well, has impressed anyone who has skied behind it. only a short list of older boats tempt me, though the right 20 year old and neglected RCB I would stray in a moment to rescue and hobby with into a stellar tug, and documented projects like yours do enhance the want.

 

Let us know how that 91 skis. Seems these boats are all over the map depending on how loaded, propped and saturated they are.

[Garn]

@DW How did you make a carbon fiber platform?

[DW]

@Garn - simple layup over a piece of corecell (hard foam board). Cut and sanded the core to desired shape. It is super stiff and complete with brackets and hydroturf top is 9 lbs.

 

I used same process to make carbon fiber engine dog house.

[UWSkier]

@DW not to hijack too much, but how'd you handle the curves of the dog house? That seems far more complicated than the platform.

[DW]

@UWSkier - It is, thus platform was first experiment:-) Echelon dog house less curvy compared to Response therefore easier. Curves done by multiple slits in the foam core to allow it to 'bend'. Much less critical for nice surface as dog house is fully covered in soft materials that hide a lot of sins.

[Kevin89MC]

Wow, awesome work @MNshortliner ! That wake looks awesome! Very cool!

[Garn]

@DW for somebody (me) who is not smart at this type of thing, can you show how you made your deck? And where do you get carbon fiber?

[Zman]

@DW Sounds cool. New thread with pictures of your carbon fiber swim deck?

[MNshortliner]

I have all the weight total numbers for removed parts.

Truck lid-18

Trunk floor-18

Trunk back panel with pockets-8

Seat back rest-38

Old floor and misc.-10

Gas tank-38

I am going to court 5 gallons of gas-40

Difference in new platform-25

So that totals 195# removed behind the motor.

The new floor is 10

The new back panel is 5

The new side panels are a lot lighter than the old but are a wash as far as weight lost behind the motor.

So all said and done 180# lighter all behind the motor coupled with the extra weight of the gas tank as far forward in the bow as possible really changes the attitude of the wake and the boat in general. Driving the boat, it feels very light and very responsive. But I don’t pull many people so it is hard to say if tracking is better or worse than before.

 

On another note I skied my first 38 off 34mph pass today. No video evidence but it felt great and can’t wait to do some more skiing and try it again.